CN108819092B

CN108819092B - Preparation method of high-pore-density aluminum or aluminum alloy material

Info

Publication number: CN108819092B
Application number: CN201810663555.2A
Authority: CN
Inventors: 白林森; 梁莲芝
Original assignee: Wuxi Henglihong Industrial Co ltd
Current assignee: Wuxi Henglihong Industrial Co ltd
Priority date: 2018-06-25
Filing date: 2018-06-25
Publication date: 2023-05-30
Anticipated expiration: 2038-06-25
Also published as: CN108819092A

Abstract

The invention provides a preparation method of an aluminum or aluminum alloy material with high pore density, which mainly comprises the steps of mechanical polishing, chemical degreasing, anodic oxidation to obtain anodic oxidation mesopores, surface coating with a corrosion-resistant coating, laser engraving grooves to expose aluminum or aluminum alloy metal, electrochemical corrosion, freeze drying, chemical corrosion, heat treatment and the like, wherein the whole preparation method has simple process, high efficiency and strong cost performance, and the pore density of the surface of the obtained aluminum or aluminum alloy is as high as 10 ⁸ ‑10 ¹⁰ Individual/cm ² 。

Description

Preparation method of high-pore-density aluminum or aluminum alloy material

Technical Field

The invention relates to the field of metal surface treatment, in particular to an aluminum and aluminum alloy surface treatment method for obtaining a high-pore-density aluminum or aluminum alloy metal substrate and a method for nano injection molding on the metal surface.

Background

The japanese large plastic (Taiseiplas) corporation invented a Nano Molding Technology (NMT) in 2002, which is a nano molding technology integrating metal and plastic, and can integrally mold metal and resin, and is widely used for housings of thin, light, portable mobile electronic products, such as computer terminals and mobile phones.

In the prior art, the NMT treatment process includes the following steps: and (3) carrying out alkali liquor treatment, acid treatment, ester-amino acid weak acid treatment and water cleaning on the metals to be combined, and then drying and injection molding. The treated metal surface has numerous micropores with a pore diameter of about 20nm formed in the metal surface, that is, many minute concave-convex structures are formed on the treated metal surface, and the injected resin enters the concave-convex structures to generate an anchoring effect. The acid treatment and the lipo-amino acid weak acid treatment steps are the most critical two steps, wherein the main purpose of the acid treatment is as follows: (a) removing excess lye from the metal surface; (b) Forming a large number of corrosion holes on the metal surface, wherein the formation of the corrosion holes is mainly due to the corrosion reaction of acid and metal, the formation of the holes is completely dependent on the composition phase and impurity phase of the metal substrate, and the corrosion rate of the composition phase and impurity phase of the metal surface relative to the acid is different, so that the corrosion holes on the metal surface are directly caused, and the corrosion holes are distributed in disorder and disordered, have different pore depths and are in a completely disordered state; therefore, the resin on the metal surface is uneven, unstable, the large and deep holes have good adhesive property, the small and shallow holes have poor adhesive property, and finally the defects of obvious mechanical property, fatigue resistance, impact toughness, good heat resistance and molding processability are caused.

Secondly, as in the CN201711254332 patent of the applicant, heng Li Hong, practice limited, the name of the invention: a method for nano injection molding of high-binding force aluminum or aluminum alloy surface, which uses multiple corrosions, the pre-corrosions can improve the surface state, determine the density and distribution of corrosion pits, and the direct current electrified corrosions can form micro-nano corrosion holes with certain length and aperture on the metal surface; the direct current electrifying secondary corrosion further corrodes the inner wall of the hole to form an unordered nanometer inner wall hole, after multiple corrosions, the formed pore channels are visible to naked eyes, the pore channels are communicated with each other, the pore walls are connected, the more the corroded holes are, the more moderate the pore diameter of the pore channels is, the bonding force is critical, but the obtained micron-sized holes are completely unordered, and finally the peeling strength is limited to 250-290kgf/cm ² In the scope of the method, the peel strength is to be improved, and then the patent CN201711256603A is named as a metal surface nano injection molding method, and ordered micro-scale holes are prepared by a template preparation method: removing the nano-scale natural oxide layer on the metal surface by one treatment method of polishing, barreling, sand blasting or shot blasting; (2) Immersing the treated metal in an alkali metal cleaning solution for cleaning; (3) washing with pure water and drying; (4) Covering the surface of a metal substrate with a metal Ni, cr, cu or alloy corrosion-resistant metal template, wherein the metal template is divided into a blank area and a metal area; (5) Physically sputtering corrosion-resistant metal on the surface of the substrate of the metal template in the step (4); (6) Taking down the corrosion-resistant metal template, immersing the metal substrate subjected to physical sputtering treatment into acid etching liquid, and etching the substrate for a plurality of times to etch uniformly distributed micron-sized etching holes, wherein the etching times are more than or equal to 1; (7) Immersing the corroded metal substrate in weak acid solution mainly containing lipo-amino acid, Forming nano holes of 20-80nm on the inner surface of the uniformly distributed micron-scale corrosion pore canal, and then washing with pure water and drying; (8) And (3) carrying out nano injection molding on the base material to enable the resin to permeate into the pore canal through injection molding. Although ordered micro-scale pores are obtained, the following problems are still faced: (1) The corrosion-resistant sputtered metal cannot be effectively removed, and the binding force and the later stability can be influenced; (2) the template preparation difficulty is high, and the equipment cost is high; (3) complicated procedures and limited operation.

The invention patent CN 106363869A of Shenzhen Baozhen gold Utility Co., ltd provides a method for forming nano holes on the surface of a metal substrate, which comprises the following steps: 1) A metal substrate titanium hanger; 2) Removing oil; 3) Washing with water; 4) Acid corrosion; 5) Washing with water; 6) Neutralizing; 7) Washing with water; 8) First electrolytic corrosion; 9) Washing with water; 10 Adhesion treatment; 11 Water washing; 12 Secondary electrolytic corrosion; 13 Water washing; 14 Chelating treatment; 15 Hot water washing; 16 Drying. The method for forming the nano holes on the surface of the metal substrate and the method for combining the liquid metal and the nano plastic raw material realize uniform nano holes on the surface of the metal substrate, and the nano plastic raw material (PPS, PBT) injection molding is adopted to realize nano combination of the metal substrate and the plastic, so that the combining force strength reaches 200KGF/CM ² Above, because the electrolytic corrosion is performed to obtain disordered holes, the strength of the binding force is general, and the stability cannot be the same as that of uniformly distributed pore channels, for example, the patent CN105500600 (1) of the company limited by bidi corporation adopts mixed acid solution of two or more of sulfuric acid, citric acid and phosphoric acid to pretreat the metal matrix to form the metal matrix with irregular corrosion holes on the surface; (2) The pretreated metal matrix is put into alkaline solution for electrochemical corrosion, and the metal matrix has corrosion holes with the width of 100-50000nm and the depth of 100-50000nm, and the same problems are faced.

Furthermore, an invention patent CN104325597 a of bidi corporation provides a method for producing a metal resin composite, the method comprising the steps of: (1) Carrying out laser etching on the metal matrix to form a metal matrix with micron-sized holes on the surface; (2) Placing the metal matrix with the micron-sized holes on the surface into an acid solution and performing electrochemical corrosion; (3) And (3) placing the metal matrix obtained after the treatment in the step (2) into a mold, and performing injection molding by using the thermoplastic resin composition to form an integrated metal resin composite body. The metal resin complex with excellent binding force is prepared by combining laser processing and electrochemical corrosion, so that the defects that the inner side inclined angle of a product cannot be processed by adopting a single laser processing method is larger than 180 degrees, the processing speed of single electrochemical corrosion is slower, the corrosion depth is insufficient and the like are overcome, and although the laser etching can obtain uniformly distributed holes on the surface of a substrate, the inner wall surface of a pore canal is smooth, and the buckling of nano injection molding resin and the pore canal is not facilitated, namely the binding force is not improved. The binding force of the invention is not necessarily the same as that obtained by the preparation method of CN 101607446A, and the method ensures that the surface of the aluminum alloy generates holes with the size of more than 1 mu m and the depth of at least 1 mu m, and the holes have staggering property and multilayering property, thereby being beneficial to the adhesion of the thermoplastic resin to the aluminum alloy. When the molten thermoplastic resin is coated on the surface of the aluminum alloy, the molten thermoplastic resin is poured into the plurality of layers of staggered micron-sized holes, the thermoplastic resin to be molten is cooled and solidified, the aluminum alloy and the thermoplastic resin are tightly buckled with each other by the plurality of layers of staggered micron-sized holes, and the aluminum alloy and the thermoplastic resin cannot be peeled off due to the staggered characteristics of the holes, so that a combination of the aluminum alloy and the thermoplastic resin with high bonding strength is generated.

In addition, there is also a prior art that uses a heat treatment to remove moisture in the oxide film in order to improve long-term stability between the resin and the nanopore, such as a surface-treated aluminum material disclosed in UACJ Length Gu Chuanzhen, inc., a method for producing the same, and a junction of the surface-treated aluminum material/resin layer (CN 106460221A), and the moisture contained in the oxide film is made to be 10. Mu.g/cm by the heat treatment ² (i.e. 100 mg/m) ² ) The following heat treatment method: the time from the end of the ac electrolysis treatment to the time when the surface temperature of the aluminum material on which the oxide film has been formed in the atmosphere exceeding 150 ℃ reaches 150 ℃ is 24 hours or less, and it is not effectiveThe moisture in the oxide film is substantially higher than 10. Mu.g/cm ² The method for removing the moisture in the oxidation pore canal through heat treatment in the prior art still needs to be improved, and based on the content, the invention provides an improved heat treatment means and is used in the field of macroporous-mesoporous corrosion pore nano injection molding.

Disclosure of Invention

Based on the problems of the prior art, the invention provides a surface treatment method of aluminum and aluminum alloy to obtain a high-pore-density aluminum or aluminum alloy metal substrate and a method for nano injection molding on the metal surface, wherein the method is simple and convenient, can effectively improve the pore density of the metal surface and improve the binding force (peeling strength) between nano injection molding resin and the substrate, and is concretely as follows:

A method for treating the surface of aluminum or aluminum alloy metal, wherein the metal is treated by the following steps: pretreatment, surface coating of corrosion-resistant coating, laser grooving, electrochemical corrosion, freeze drying, chemical corrosion and heat treatment for removing moisture and coating in a metal substrate, wherein the heat treatment steps are as follows: placing the metal substrate subjected to chemical corrosion in a volume fraction of 2-5% H ₂ /N ₂ In the mixed atmosphere, the temperature programming process is 15 ^o C/min up to 160 ^o C, preserving the heat for 0.5-2 h, and then 5 ^o C/min up to 365 ^o C, preserving the heat for 2-3 hours, and then 20 ^o C/min up to 500 ^o C, keeping the temperature for 0.5-1 h, purging the mixed gas and cooling to room temperature, wherein the finally obtained metal surface contains electrochemical corrosion macropores and chemical corrosion mesopores, the pore diameter of the macropores is 1-200 mu m, the pore depth of the macropores is 10-90 mu m, the pore diameter of the mesopores is 2-40nm, and the moisture is lower than 30mg/m ² 。

Further, the pore diameter of the macropores is 50-60 mu m, and the pore diameter of the mesopores is 10-20nm.

Further, the pretreatment is alkaline degreasing pretreatment, the alkaline degreasing agent consists of 30g/L sodium carbonate, 30g/L trisodium phosphate, 15g/L sodium silicate and deionized water, and the treatment temperature is 50 ^o C, performing operation; or acid degreasing pretreatment, wherein the acid degreasing agent consists of 100ml/L of d=1.84 sulfuric acid and 25g/L of sulfuric acid The OP emulsifier and deionized water are combined, and the treatment temperature is room temperature;

further, the method further comprises polishing, buffing, rolling, sand blasting or shot blasting to remove the nano-scale natural oxide layer on the surface of the aluminum or aluminum alloy before chemical degreasing.

Further, the surface coated corrosion-resistant coating is a thermoplastic resin coating, such as one of polyvinyl chloride, polystyrene, polyethylene, polypropylene and polyamide, and the coating mode is spraying, and the thickness of the coating is 5-20 mu m.

Further, grooves obtained by laser are regularly and uniformly distributed on a metal substrate containing a coating, the aperture of the grooves is 1-200 mu m, the depth of the grooves is greater than or equal to the thickness of the surface coated with the corrosion-resistant coating so as to expose the metal of the substrate, parameters of the grooves are used for conducting electricity, and the grooves are etched by laser: the current is 5-10A, and the frequency is 2-4KHz.

Further, the electrochemical corrosion of the macropores comprises the following steps: taking pre-corroded metal as an anode, graphite as a cathode, and simultaneously soaking in a mixed corrosive liquid, and connecting a direct-current power supply, wherein the mixed corrosive liquid comprises 1-3 wt.% hydrochloric acid, 0.5-1 wt.% sulfuric acid, 0.2-1 wt.% oxalic acid and 0.1-0.15 wt.% AlCl ₃ The solution is assisted by ultrasonic treatment in the direct current power-on corrosion process, the ultrasonic frequency is 40-100 KHz, and the temperature is 30-40 ^o C, 3-5 min, and current density of 50-200mA/cm ² And then washing with pure water, wherein the obtained etched macropores have the same pore size as the grooves, the pore size of the macropores is 1-200 mu m, and the depth is 10-90 mu m.

Further, the freeze-drying step is as follows: placing the electrochemically corroded metal substrate at a temperature lower than 0 DEG C ^o C, placing the mixture in a refrigerator or a freezer for 0.5-5 h, then placing the mixture in a freeze dryer, and keeping the cold trap temperature at-50 ℃ under the vacuum degree of less than 10 Pa ^o And C, freeze-drying for 0.5-5 h under the condition of removing water in the holes.

Further, the process of chemically corroding the mesopores is to put the freeze-dried metal matrix into T liquid, and form chemically corroding the mesopores on the walls of the macropores by corrosion, wherein the main component of the T liquid is lipomine.

Then carrying out nano injection molding on the surface of the aluminum or aluminum alloy substrate prepared by the method, wherein the specific steps are as follows: (1) mechanical polishing; (2) chemical degreasing; (3) coating the surface with a corrosion-resistant coating; (4) laser engraving grooves to expose aluminum or aluminum alloy metal; (5) Electrochemical corrosion is carried out on the part exposed out of aluminum or aluminum alloy metal to obtain macropores; (6) freeze-drying; (7) chemically corroding to obtain mesopores; (8) heat treating to remove moisture and coating from the metal substrate; (9) And (3) nano injection molding, wherein the melting temperature of the resin of the nano injection molding is 200-300 ℃, the temperature of the nano injection molding is 70-90 ℃, the pressure of the injection molding is 70-130 mpa, and the speed of the nano injection molding is 400-900 mm/s.

Further, the heat treatment steps are as follows: placing the metal substrate subjected to chemical corrosion in a volume fraction of 2-5% H ₂ /N ₂ The temperature programming is carried out in the mixed atmosphere, and the temperature programming process is 15 ^o C/min up to 160 ^o C, preserving the heat for 0.5-2 h, and then 5 ^o C/min up to 365 ^o C, preserving the heat for 2-3 hours, and then 20 ^o C/min up to 500 ^o And C, keeping the temperature for 0.51h, and purging the mixed gas to room temperature.

Further, the mechanical polishing is selected from one of buffing, polishing, tumbling, sand blasting or shot blasting for removing the nano-scale natural oxide layer on the surface of aluminum or aluminum alloy,

further, the chemical degreasing comprises alkaline degreasing or acidic degreasing, wherein the alkaline degreasing agent consists of 30g/L sodium carbonate, 30g/L trisodium phosphate, 15g/L sodium silicate and deionized water, and the treatment temperature is 50 ^o C, performing operation; the acid degreasing agent consists of 100ml/L d=1.84 sulfuric acid, 25g/LOP emulsifier and deionized water, and the treatment temperature is room temperature;

Further, the freeze drying: placing the electrochemically corroded metal substrate at a temperature lower than 0 DEG C ^o C, placing the mixture in a refrigerator or a freezer for 0.5-5 h, then placing the mixture in a freeze dryer, and keeping the cold trap temperature at-50 ℃ under the vacuum degree of less than 10 Pa ^o And C, freeze-drying for 0.5-5 h under the condition of removing water in the holes.

On the basis of the uniformly distributed electrochemical corrosion macropores obtained by the surface treatment and the chemically corroded mesopores arranged on the pore walls of the macropores, further optimizing the surface treatment process to obtain the aluminum or aluminum alloy material with high pore density, wherein the high pore density metal substrate has a structure comprising mesopores and macropores, the mesopores are divided into anodic oxidation mesopores and chemical corrosion mesopores, wherein the anodic oxidation mesopores are distributed between macropores and macropores, the chemical corrosion mesopores are distributed on the pore walls of the macropores, the macropores are uniformly distributed on the surface of the aluminum or aluminum alloy, the macropores are obtained by electrochemical corrosion, the pore diameter range of the anodic oxidation mesopores is 10-90nm, the pore diameter range of the chemical corrosion mesopores is 2-40nm, and the macropores are large The pore diameter range is 1-200 mu m, the pore depth of the macropores is 10-90 mu m, and the pore density of the aluminum or aluminum alloy surface is 10 ⁸ -10 ¹⁰ Individual/cm ² The water content of the surface of the aluminum or aluminum alloy is lower than 30mg/m ² 。

Further, the anodic oxidation mesoporous has a pore diameter ranging from 30 nm to 50nm, the chemical corrosion mesoporous has a pore diameter ranging from 10 nm to 20nm, and the macroporous has a pore diameter ranging from 50 μm to 60 μm.

Further, the anodic oxidation mesoporous obtaining conditions are as follows: aluminum or aluminum alloy is used as an anode, inert metal or graphite is used as a cathode, an anodic oxidation solution is 10-20wt.% of mixed acid aqueous solution, the mixed acid is sulfuric acid and oxalic acid, and the mass ratio of the sulfuric acid to the oxalic acid is (1-1.5): 1, an operating voltage of 10-30V and a temperature of 20-30 ^o C, the time is 1-2 h.

Further, the conditions of electrochemical corrosion of the macropores are as follows: taking aluminum or aluminum alloy obtained through anodic oxidation as an anode, taking inert metal or graphite as a cathode, and simultaneously soaking in a mixed corrosive liquid, and connecting a direct current power supply, wherein the mixed corrosive liquid comprises 1-3 wt.% hydrochloric acid, 0.5-1 wt.% sulfuric acid, 0.2-1 wt.% oxalic acid and 0.1-0.15 wt.% AlCl ₃ The solution is subjected to direct current power-on corrosion assisted by ultrasonic treatment, the ultrasonic frequency is 40-100 KHz, and the temperature is 30-40 ^o C, 3-5 min, and current density of 50-200mA/cm ² 。

Further, the obtaining conditions of the chemically etched mesopores are as follows: freeze drying aluminum or aluminum alloy obtained by electrochemical corrosion, and soaking in T liquid with main component of lipomine for 0.5-2 hr at 20-50 deg.C ^o C。

Further, the aluminum or aluminum alloy is subjected to one treatment method of polishing, barreling, sand blasting or shot blasting to remove a nanoscale natural oxide layer on the surface of the aluminum or aluminum alloy, and then is subjected to an anodic oxidation operation after acidic or alkaline degreasing.

Further, after the aluminum or aluminum alloy is soaked in the T liquid, the temperature is raised by a program.

Further, the procedure of the program heating heat treatment is as follows: at normal temperature, 15 ^o C/min literTo 160 ^o C, preserving the heat for 0.5-2 h, and then 5 ^o C/min up to 365 ^o C, preserving the heat for 2-3 hours, and then 20 ^o C/min up to 500 ^o And C, keeping the temperature for 0.5-1 h, and purging the mixed gas to room temperature.

Further, the uniformly distributed macropores are obtained by a template method.

The preparation method of the aluminum or aluminum alloy material with high pore density comprises the following steps: (1) mechanical polishing; (2) chemical degreasing; (3) anodic oxidation to obtain anodic oxidation mesopores; (4) coating a corrosion-resistant coating on the surface; (5) laser engraving grooves to expose aluminum or aluminum alloy metal; (6) Electrochemical corrosion is carried out on the part exposed out of aluminum or aluminum alloy metal to obtain macropores; (7) freeze-drying; (8) chemical etching to obtain chemical etching mesopores; (7) heat treating to remove moisture and coating from the metal substrate; the final pore density of the aluminum or aluminum alloy surface obtained was 10 ⁸ -10 ¹⁰ Individual/cm ² The water content of the surface of the aluminum or aluminum alloy is lower than 30mg/m ² 。

Further, the mechanical polishing is one of polishing, tumbling, sand blasting or shot blasting to remove the nano-scale natural oxide layer on the surface of the aluminum or aluminum alloy, the chemical degreasing is an acidic or alkaline degreasing agent, the alkaline degreasing agent consists of 30g/L sodium carbonate, 30g/L trisodium phosphate, 15g/L sodium silicate and deionized water, and the treatment temperature is 50 ^o C, performing operation; or acidic degreasing pretreatment, wherein the acidic degreasing agent consists of 100ml/L of d=1.84 sulfuric acid, 25g/LOP emulsifier and deionized water, and the treatment temperature is room temperature.

Further, the step of anodic oxidation is as follows: aluminum or aluminum alloy is used as an anode, inert metal or graphite is used as a cathode, an anodic oxidation solution is 10-20wt.% of mixed acid aqueous solution, the mixed acid is sulfuric acid and oxalic acid, and the mass ratio of the sulfuric acid to the oxalic acid is (1-1.5): 1, an operating voltage of 10-30V and a temperature of 20-30 ^o And C, the time is 1-2 h, and 10-90nm mesopores are formed on the surface of aluminum or aluminum alloy by anodic oxidation.

Further, the corrosion-resistant coating is selected from one of polyvinyl chloride, polystyrene, polyethylene, polypropylene and polyamide.

Further, grooves obtained by laser etching are regularly and uniformly distributed on a metal substrate containing a coating, the aperture of the grooves is 1-200 mu m, the depth of the grooves is larger than the sum of the thicknesses of the surface coated with the corrosion-resistant coating and the anodic oxide layer so as to expose the metal of the substrate, parameters of the grooves are used for conducting electricity, and the grooves are etched by laser: the current is 5-10A, and the frequency is 2-4KHz.

Further, taking aluminum or aluminum alloy obtained by laser etching as an anode, taking inert metal or graphite as a cathode, and simultaneously soaking in a mixed corrosive liquid, and connecting a direct current power supply, wherein the mixed corrosive liquid comprises 1-3 wt.% of hydrochloric acid, 0.5-1 wt.% of sulfuric acid, 0.2-1 wt.% of oxalic acid and 0.1-0.15 wt.% of AlCl ₃ The solution is subjected to direct current power-on corrosion assisted by ultrasonic treatment, the ultrasonic frequency is 40-100 KHz, and the temperature is 30-40 ^o C, 3-5 min, and current density of 50-200mA/cm ² The pore diameter of the obtained macropores is consistent with the pore diameter of the laser engraving groove, the range is 1-200 mu m, and the pore depth of the macropores is 10-90 mu m.

Further, the step of chemical etching is as follows: freeze drying aluminum or aluminum alloy obtained by electrochemical corrosion, and soaking in T liquid with main component of lipomine for 0.5-2 hr at 20-50 deg.C ^o And C, the mesoporous pore diameter range of chemical corrosion is 2-40nm.

Further, the heat treatment process can remove moisture and the corrosion-resistant coating simultaneously.

Further, the heat treatment process is as follows: at normal temperature, 15 ^o C/min up to 160 ^o C, preserving the heat for 0.5-2 h, and then 5 ^o C/min up to 365 ^o C, preserving the heat for 2-3 hours, and then 20 ^o C/min up to 500 ^o And C, keeping the temperature for 0.5-1 h, and purging the mixed gas to room temperature.

Then carrying out nano injection molding on the surface of the high-pore-density aluminum or aluminum alloy substrate prepared by the method to obtain the high-stability metal material with the surface coated with resin, wherein the preparation method comprises the following steps: (1) mechanical polishing; (2) chemical degreasing; (3) anodic oxidation to obtain anodic oxidation mesopores; (4) coating a corrosion-resistant coating on the surface; (5) laser engraving grooves to expose aluminum or aluminum alloy metal; (6) Electrochemical corrosion is carried out on the part exposed out of aluminum or aluminum alloy metal to obtain macropores; (7) freeze-drying; (8) chemical etching to obtain chemical etching mesopores; (9) heat treating to remove moisture and coating from the metal substrate; (10) The nano injection molding is carried out, wherein the melting temperature of the resin of the nano injection molding is 240-350 ℃, the temperature of the nano injection molding is 70-90 ℃, the pressure of the injection molding is 70-130 mpa, the speed of the nano injection molding is 400-900 mm/s, and the metal material is aluminum or aluminum alloy.

Further, grooves obtained by laser etching are regularly and uniformly distributed on a metal substrate containing a coating, the aperture of the grooves is 1-200 mu m, the depth of the grooves is greater than or equal to the thickness of the surface coated with the corrosion-resistant coating so as to expose the metal of the substrate, parameters of the grooves are used for conducting electricity, and the grooves are etched by laser: the current is 5-10A, and the frequency is 2-4KHz.

Further, the composite material is used in the field of electronic terminal housings.

The surface treatment of the invention obtains a metal substrate or a nano injection molding product, and has the following excellent technical effects:

(1) The electrochemical corrosion macropores are uniformly distributed on the metal surface, so that the bonding force between the nano injection molding resin and the metal substrate is stable, namely the peeling strength of the nano injection molding product is uniform and the volatility is small.

(2) The pore walls of the electrochemical corrosion macropores are provided with chemical corrosion mesopores, and anodic oxidation mesopores are arranged among the macropores, namely, the porosity of the metal surface is extremely high, which is favorable for improving the binding force of the nano injection molding resin and the metal substrate.

(3) The heat treatment effectively removes the bound water or free water inside or outside the metal pore canal, which is beneficial to improving the stability between the nano injection molding resin and the metal base material.

(4) The method can remove the protective coating simply and conveniently while removing the moisture through heat treatment, and does not need an additional protective layer removing process, namely the whole metal surface treatment process has high efficiency and strong cost performance.

(5) The mechanical property, fatigue resistance, impact toughness, heat resistance and molding processability of the nano injection molding product are all higher than those of products in the same kind of markets.

(6) The nano injection molding process for the metal surface is simple, safe and environment-friendly, and is suitable for industrial production in a production line.

Drawings

FIG. 1: (a) Stripping of injection molding resin due to high moisture content in the prior art; (b) The invention removes water through heat treatment, and the stability of injection molding resin and base material is combined with schematic diagram.

Fig. 2: the prior art uses a template method to prepare uniformly distributed corrosion holes (for example, the application number is CN 201711256603A).

Fig. 3: the nano injection molding aluminum alloy prepared by the invention is shown in the schematic diagram.

Fig. 4: the invention relates to a schematic drawing of aluminum or aluminum alloy surface treatment and nano injection molding.

Fig. 5: the aluminum or aluminum alloy metal surface treatment schematic diagram of the invention.

Fig. 6: the invention relates to an aluminum or aluminum alloy metal nano injection molding schematic diagram.

Fig. 7: the preparation process of the high-stability metal material with the surface coated with resin is schematically shown.

Fig. 8: the preparation process of the aluminum or aluminum alloy material with high pore density is schematically shown.

Fig. 9: the invention relates to a high-pore-density aluminum or aluminum alloy metal nano injection schematic diagram.

Description of the drawings: 1. the aluminum or aluminum alloy substrate, 2 a corrosion-resistant coating, 3 grooves, 4 electrochemical corrosion macropores, 5 chemical corrosion mesopores, 6 nano injection molding resin layers, 7 anodic oxidation mesopores and 8 water.

Detailed Description

As shown in figure 1 (a), in the prior art, as shown in figure 1 (b), in the corroded nanochannel, direct nano injection molding is performed, due to the adhesion and sealing of the polymer resin, moisture in the nanochannel cannot be effectively volatilized, after long-time use, steam is generated, and peeling stress is generated at the interface between the injection molding resin and the metal nanochannel, so that the adhesiveness and stability of a product after nano injection molding are affected, in this way, as shown in figure 1 (b), after the nanochannel is formed, a substrate is subjected to heat treatment, so that the moisture is effectively removed, and finally the influence of the moisture on the product is obviously reduced in the use process of the nano injection molded product, however, a heat treatment means that "from the end of alternating current electrolysis treatment until the surface temperature of the aluminum material with an oxide film formed in an atmosphere exceeding 150 ℃ reaches 150 ℃ is not capable of effectively removing the moisture in the oxide film within 24 hours", and the moisture in the oxide film is actually higher than 10 mu g/cm ² The heat treatment means is to be improved.

Based on the above, the present invention improves the pore morphology of the substrate surface, and effectively reduces the unavoidable moisture content during pore formation by heat treatment, specifically as follows:

first, as for the choice of the base material, pure aluminum or aluminum alloy may be used as the aluminum material used in the present invention, and the aluminum alloy component is not particularly limited, and various aluminum alloys including six-series and seven-series alloys may be used. The metal used in the present invention may be a light metal suitable for use as a metal shell of an electronic terminal, such as Mg, ti, or stainless steel, and the shape thereof is not particularly limited, and a flat plate-like material is preferably used in view of stably forming a nano injection-molded film.

Example 1

The treatment method for the aluminum or aluminum alloy metal substrate mainly comprises the following steps (shown in the accompanying figures 4-5):

(1) Pretreatment: the method comprises the steps of mechanically treating the surface of aluminum or aluminum alloy metal to remove a nanoscale natural oxide layer on the surface of aluminum or aluminum alloy, wherein the oxide layer has lower binding force with a base material and poorer physical and chemical properties, so that the mechanical pretreatment process is indispensable, and the mechanical treatment comprises one of polishing, barreling, sand blasting or shot blasting; then, alkaline or acid degreasing agent is used to chemically remove grease on the metal surface, and a layer of greasy dirt is inevitably adhered to the metal surface when the metal substrate is mechanically treated, so that the greasy dirt on the metal surface must be removed in order to ensure firm combination of the substrate and the oxide film or nano injection molding material.

The chemical degreasing liquid mainly comprises an alkaline degreasing agent and an acidic degreasing agent, wherein the alkaline degreasing agent consists of 30g/L sodium carbonate, 30g/L trisodium phosphate, 15g/L sodium silicate and deionized water, and the treatment temperature is 50 ^o C, performing operation; the alkaline degreasing agent is nontoxic and low in price, and is used for removing greasy dirt by means of saponification and emulsification of the solution. Sodium carbonate has certain alkalinity, has no obvious corrosion effect on aluminum materials, can be used for converting CO2 in the absorbed air into sodium bicarbonate, and has good buffering effect on an alkaline degreasing agent; trisodium phosphate also has oil removing and buffering effects and certain emulsifying capacity; sodium silicate has good surface activity and certain saponification capacity, and has the function of a corrosion inhibitor.

The acid degreasing agent consists of 100ml/L d=1.84 sulfuric acid, 25g/L OP emulsifier and deionized water, the treatment temperature is room temperature, and the acid degreasing agent is suitable for treating a small amount of metal base materials with rusted surfaces.

(2) Coating a corrosion-resistant coating on the surface; the surface-coated corrosion-resistant coating is a thermoplastic resin coating, such as polyvinyl chlorideOne of alkene, polystyrene, polyethylene, polypropylene and polyamide, and the thermoplastic resin coating is 500 ^o C can be effectively decomposed and removed under the anaerobic condition, so polystyrene is preferable, the coating mode is spray coating or electrophoresis plating, spray coating is preferable, the thickness of the coating is 3-30 mu m, preferably 5-20 mu m, more preferably 5-8 mu m, and the corrosion-resistant coating coated on the surface mainly acts as a protective layer or template layer and is removed by heat treatment in the later required process, so the coating with low cost, high hardness, chemical corrosion resistance, good insulativity, easy removal and thinness is preferable, namely the resin coating selected by the principle is included in the scope of the invention.

(3) Laser engraving grooves; the grooves are blind holes, namely, holes are punched through a program design and a short-focal-length objective lens, so that the grooves etched by laser are regularly and uniformly distributed on a metal substrate containing a coating, the aperture of the grooves is 1-200 mu m, the depth of the grooves is greater than or equal to the thickness of the surface coating corrosion-resistant coating so as to expose the metal substrate, and parameters of the grooves etched by laser are used for conducting: the current is 5-10A, the frequency is 2-4KHz, the metal substrate is exposed at the position of the groove, namely, the metal substrate can conduct electricity near the groove, the groove position can be corroded through the subsequent electrochemical corrosion treatment, the groove with the same size as the etched groove is generated, the insulating and corrosion-resistant part which is not etched can not be corroded, so that the groove coating etched by the laser can serve as a template, the holes which are chemically corroded can be uniformly distributed, the punching range of the laser punching machine in the prior art is as small as nano-scale, namely, the distribution and the size of the groove can be regulated and controlled only through the program design of the laser macro-porous machine, and the micro-scale adjustable and uniformly distributed macroporous pore canal is prepared on the surface of the metal substrate.

(4) Electrochemical corrosion; taking pre-corroded metal as an anode, graphite as a cathode, and simultaneously soaking in a mixed corrosive liquid, and connecting a direct-current power supply, wherein the mixed corrosive liquid comprises 1-3 wt.% hydrochloric acid, 0.5-1 wt.% sulfuric acid, 0.2-1 wt.% oxalic acid and 0.1-0.15 wt.% AlCl ₃ Ultrasonic treatment is assisted in the process of direct current electrified corrosion, and ultrasonic frequency is high40-100 KHz, and a temperature of 30-40 DEG C ^o C, 3-5 min, and current density of 50-200mA/cm ² And then washing with pure water to obtain corrosion macropores with the same pore size as the grooves, wherein the pore size of the macropores is 1-200 mu m, the depth is 10-90 mu m, the pore size of the macropores is preferably 50-60 mu m, and the pore size is too small or too shallow, so that the sufficient contact between the resin and the substrate is not facilitated, and the bonding force is too small. On the other hand, too large or too deep pore diameter can reduce the binding force between the electrochemical oxidation pores and the aluminum substrate, which is unfavorable for finally obtaining the binding force of the product.

In addition, in the direct current electrifying corrosion process, metal Al in the groove part is oxidized to generate Al ³⁺ And then, in the electrolytic corrosion mixed solution, chloride ions are necessary, and belong to one of the ions with strongest corrosion performance in halogen ions, so that the chloride ions can penetrate through an oxide film to erode and dissolve aluminum base to form an etching pit. The single-component HCl corrosive liquid is unfavorable for corrosion on the metal surface and even can cause excessive corrosion, so that the oxidizing acid sulfuric acid and oxalic acid are required to be added into the corrosive liquid, wherein AlCl ₃ For improving Cl ^- The concentration is favorable for vertical corrosion, and the vertical corrosion is mainly carried out along the {100} crystal face, so that good corrosion effect is ensured, wherein ultrasonic waves are favorable for further deepening pore channels generated by pre-corrosion, so that the corroded Al ³⁺ The pores are removed, and the micropores formed in the process are most.

(5) Freeze drying; placing the electrochemically corroded metal substrate at a temperature lower than 0 DEG C ^o C, placing the mixture in a refrigerator or a freezer for 0.5-5 h, then placing the mixture in a freeze dryer, and keeping the cold trap temperature at-50 ℃ under the vacuum degree of less than 10 Pa ^o C, freeze-drying for 0.5-5 h under the condition of removing water in the holes, wherein the drying mode can be other conventional drying modes, such as cold air drying, an air drying box, an inert gas drying box, a vacuum drying box and the like, and the freeze-drying is preferred, and mainly based on the following considerations: (1) In a closed environment, a vacuum pump of the condensing dryer can be effectively arrangedForming a vacuumizing state, which is beneficial to removing moisture in the pore canal; (2) The moisture is sublimated from solid state to gas state, and the moisture in the air can be effectively removed through continuous freezing, sublimation and re-drying; (3) facilitating subsequent chemical etching reactions.

(6) Chemical corrosion; the process of the chemical corrosion mesoporous is that a freeze-dried metal matrix is placed into T liquid, and chemical corrosion mesoporous is formed on the wall of a macroporous hole through corrosion, the main component of the T liquid is lipomine, the T treatment liquid is commercially available T treatment liquid and is used for forming chemical corrosion mesoporous on the electrochemical corrosion macropores, the pore diameter range of the mesoporous is 2-40nm, and the pore diameter range of the mesoporous is 10-20nm.

(7) Heat treatment removes moisture and coating from the metal substrate: wherein the heat treatment steps are as follows: placing the metal substrate subjected to chemical corrosion in a volume fraction of 2-5% H ₂ /N ₂ In the mixed atmosphere, the temperature programming process is 15 ^o C/min up to 160 ^o C, preserving the heat for 0.5-2 h, and then 5 ^o C/min up to 365 ^o C, preserving the heat for 2-3 hours, and then 20 ^o C/min up to 500 ^o C, keeping the temperature for 0.5-1 h, purging the mixed gas to room temperature, wherein the heat treatment mode is mainly obtained according to TGA-DTA analysis, and the temperature is 100-160 ^o C is the moisture physically adsorbed or weakened chemisorbed on the surface of the substrate or the surface of the macropores, 365 is selected ^o C treatment for 2-3 h mainly for removing water molecules in the holes and water molecules with strong chemical adsorption, wherein the water in the positions is difficult to desorb due to capillary (surface) tension and the like, and the high temperature is 500 DEG C ^o C is mainly used for removing the protective coating on the surface, and at the temperature, polystyrene can be directly decomposed and gasified, and has no influence on the pore canal of the substrate.

The surface of the finally obtained metal substrate contains electrochemical corrosion macropores and chemical corrosion mesopores, wherein the pore diameter of the macropores is 1-200 mu m, the pore depth of the macropores is 10-90 mu m, the pore diameter of the mesopores is 2-40nm, and the moisture is lower than 30mg/m ²

In addition, it is clear that the electrochemical corrosion macropores and the chemical corrosion mesopores on the surface of the metal substrate prepared by the method are in a disordered state, as shown in fig. 3. The uniform distribution of macropores in the invention means that the protective coating is etched by laser to obtain macropores with uniform distribution, and uniform corrosion is performed to realize uniform pore depth of the macropores as much as possible, but for the sake of clearing and concisely explaining the states of the macropores in the metal substrate, the macropores and the mesopores are designed to be more regular and orderly in the schematic drawings of fig. 5-6, and the schematic drawings do not represent the final states of the macropores and the mesopores of the surface substrate of the invention.

Example 2

As previously mentioned, the present inventors CN201711256603a patent prepares ordered microscale pores by a template preparation process: removing the nano-scale natural oxide layer on the metal surface by one treatment method of polishing, barreling, sand blasting or shot blasting; (2) Immersing the treated metal in an alkali metal cleaning solution for cleaning; (3) washing with pure water and drying; (4) Covering the surface of a metal substrate with a metal Ni, cr, cu or alloy corrosion-resistant metal template, wherein the metal template is divided into a blank area and a metal area; (5) Physically sputtering corrosion-resistant metal on the surface of the substrate of the metal template in the step (4); (6) Taking down the corrosion-resistant metal template, immersing the metal substrate subjected to physical sputtering treatment into acid etching liquid, and etching the substrate for a plurality of times to etch uniformly distributed micron-sized etching holes, wherein the etching times are more than or equal to 1; (7) Immersing the corroded metal substrate in weak acid solution mainly containing lipo-amino acid to form nano holes of 20-80nm on the inner surface of uniformly distributed micron-scale corrosion pore channels, and then washing with pure water and drying; (8) And (3) carrying out nano injection molding on the base material to enable the resin to permeate into the pore canal through injection molding. Although ordered micro-scale pores are obtained, a significant problem is still faced: corrosion-resistant sputtered metal cannot be effectively removed, and the binding force and the later stability can be affected. As shown in fig. 2, the corrosion-resistant alloy template subjected to physical sputtering cannot be effectively removed and is finally clamped between injection molding resin and a substrate, and as the surface of the corrosion-resistant alloy template subjected to physical sputtering does not contain any pore canal, the bonding force between the substrate and the resin is not high, and moisture in the substrate is not effectively removed, the problems can obviously affect the finally obtained nano injection molding mobile terminal product, namely the porosity of the surface of the metal substrate in the prior art and the moisture in the pore are improved, and the following improvement is made based on the problems.

Next, as described in example 1, although the coating template was effectively removed by heat treatment, there was no problem that the corrosion resistant alloy template physically sputtered in CN201711256603a patent could not be effectively removed and eventually was sandwiched between the injection molding resin and the substrate, but the metal substrate still remained smooth below the coating template (i.e., there was no hole in the metal substrate below the coating template), and when nano injection molding, the injection molding resin could be effectively bonded or buckled with the electrochemically corroded macropores and chemically corroded mesopores, could not be bonded with the metal substrate with smooth surface (the metal substrate below the coating template), and eventually the bonding strength of the nano injection molding resin and the metal substrate would be affected. Based on the content, the embodiment 2 of the invention is improved on the basis of the embodiment 1, and an aluminum or aluminum alloy material with high pore density is prepared and is convenient to be used as a nano injection molding base material.

First, the selection of the substrate is described in the relevant section of example 1.

Second, the improved metal substrate of the present invention has the following structure: an aluminum or aluminum alloy material (1) with high pore density, wherein the pores comprise mesopores and macropores (4), the mesopores are divided into anodic oxidation mesopores (7) and chemical corrosion mesopores (8), wherein the anodic oxidation mesopores (7) are distributed between the macropores (4) and the macropores (4), the chemical corrosion mesopores (8) are distributed on the wall of the macropores (4), the macropores are uniformly distributed on the surface of the aluminum or aluminum alloy (1), the macropores are obtained through electrochemical corrosion, the pore diameter of the anodic oxidation mesopores (7) is 10-90nm, the pore diameter of the chemical corrosion mesopores (8) is 2-40nm, the pore diameter of the macropores (4) is 1-200 mu m, the pore depth of the macropores is 10-90 mu m, and the pore density of the aluminum or aluminum alloy surface is 10 ⁸ -10 ¹⁰ Individual/cm ² The water content of the surface of the aluminum or aluminum alloy is lower than 30mg/m ² 。

Further, the anodic oxidation mesoporous pore diameter range is preferably 30-50nm, the chemical corrosion mesoporous pore diameter range is preferably 10-20nm, the macroporous pore diameter range is 50-60 μm, if the anodic oxidation or chemical corrosion pore diameter is smaller than 10nm, the problem of capillary effect is generated, the nano injection molding resin cannot effectively enter the nano pore canal, the contact area is insufficient, and therefore, sufficient binding force cannot be obtained, and if the anodic oxidation pore canal size is larger than 50nm, the binding force between the nano injection molding resin and the pore canal is improved, but the binding force between the pore canal and a base material is reduced, and the performance of a final product is further reduced.

Further, the conditions for obtaining the anodic oxidation mesoporous are as follows: aluminum or aluminum alloy is used as an anode, inert metal or graphite is used as a cathode, an anodic oxidation solution is 10-20wt.% of mixed acid aqueous solution, the mixed acid is sulfuric acid and oxalic acid, and the mass ratio of the sulfuric acid to the oxalic acid is (1-1.5): 1, an operating voltage of 10-30V and a temperature of 20-30 ^o C, the time is 1-2 h.

Further, conditions for electrochemically etching the macropores are: taking aluminum or aluminum alloy obtained through anodic oxidation as an anode, taking inert metal or graphite as a cathode, and simultaneously soaking in a mixed corrosive liquid, and connecting a direct current power supply, wherein the mixed corrosive liquid comprises 1-3 wt.% hydrochloric acid, 0.5-1 wt.% sulfuric acid, 0.2-1 wt.% oxalic acid and 0.1-0.15 wt.% AlCl ₃ The solution is subjected to direct current power-on corrosion assisted by ultrasonic treatment, the ultrasonic frequency is 40-100 KHz, and the temperature is 30-40 ^o C, 3-5 min, and current density of 50-200mA/cm ² In the direct current electrified corrosion process, metal Al in the groove part is oxidized to generate Al ³⁺ And then, in the electrolytic corrosion mixed solution, chloride ions are necessary, and belong to one of the ions with strongest corrosion performance in halogen ions, so that the chloride ions can penetrate through an oxide film to erode and dissolve aluminum base to form an etching pit. The single-component HCl corrosive liquid is unfavorable for corrosion on the metal surface and even can cause excessive corrosion, so that the oxidizing acid sulfuric acid and oxalic acid are required to be added into the corrosive liquid, wherein AlCl ₃ For improving Cl ^- The concentration is favorable for vertical corrosion, and the vertical corrosion is mainly carried out along the {100} crystal face, so that good corrosion effect is ensured, wherein ultrasonic waves are favorable for further deepening pore channels generated by pre-corrosion, so that the corroded Al ³⁺ The pores are removed, and the micropores formed in the process are most.

Further, the aluminum or aluminum alloy is subjected to an anodic oxidation operation after removing a nano-scale natural oxide layer on the surface of the aluminum or aluminum alloy by one of polishing, buffing, tumbling, sand blasting or shot blasting, followed by acidic or alkaline degreasing, in particular, see the contents related to example 1.

Further, after the aluminum or aluminum alloy is soaked in the T liquid, the process of the program heating heat treatment is as follows: at normal temperature, 15 ^o C/min up to 160 ^o C, preserving the heat for 0.5-2 h, and then 5 ^o C/min up to 365 ^o C, preserving the heat for 2-3 hours, and then 20 ^o C/min up to 500 ^o And C, keeping the temperature for 0.5-1 h, and purging the mixed gas to room temperature.

Namely, macropores electrochemically etched by a template method are uniformly distributed on the surface of the high-pore-density aluminum or aluminum alloy material, anodic mesoporous is arranged between the macropores, chemically etched mesopores are distributed on the surface of the electrochemically etched macropores, and the range of pore density of the finally obtained aluminum or aluminum alloy surface is 10 ⁸ -10 ¹⁰ Individual/cm ² Has a pore density in a range higher than that of the same type of nano injection molded substrate (typically 10 ⁶ -10 ⁸ Individual/cm ² ）。

Based on the description of the aluminum or aluminum alloy material with high pore density, the preparation method of the aluminum or aluminum alloy material with high pore density is as follows: (1) mechanical polishing; (2) chemical degreasing; (3) anodic oxidation to obtain anodic oxidation mesopores; (4) Surface coating corrosion resistanceA coating; (5) laser engraving grooves to expose aluminum or aluminum alloy metal; (6) Electrochemical corrosion is carried out on the part exposed out of aluminum or aluminum alloy metal to obtain macropores; (7) freeze-drying; (8) chemical etching to obtain chemical etching mesopores; (9) heat treating to remove moisture and coating from the metal substrate; the final pore density of the aluminum or aluminum alloy surface obtained was 10 ⁸ -10 ¹⁰ Individual/cm ² The water content of the surface of the aluminum or aluminum alloy is lower than 30mg/m ² 。

Further, grooves obtained by laser etching are regularly and uniformly distributed on a metal substrate containing a coating, the aperture of the grooves is 1-200 mu m, the depth of the grooves is larger than the sum of the thicknesses of the surface coated with the corrosion-resistant coating and the anodic oxide layer so as to expose the metal of the substrate, parameters of the grooves are used for conducting electricity, and the grooves are etched by laser: since the anodized mesopores are alumina and the weakly conductive material, and the current of 5-10A and the frequency of 2-4KHz, as in example 1, the electrochemical etching of macropores cannot be effectively achieved by electrochemical etching without removing the oxide film, the depth of the laser etched recess must be greater than, or at least equal to, the sum of the thicknesses of the surface-coated corrosion-resistant coating and the anodized layer to expose the substrate metal, facilitating the subsequent telephony etching process.

Example 3

PPS nano injection molding was performed on the metal substrate obtained in example 1.

The method comprises the following specific steps:

(1) Mechanically polishing; (2) chemical degreasing; (3) coating the surface with a corrosion-resistant coating; (4) laser engraving grooves to expose aluminum or aluminum alloy metal; (5) Electrochemical corrosion is carried out on the part exposed out of aluminum or aluminum alloy metal to obtain macropores; (6) freeze-drying; (7) chemically corroding to obtain mesopores; (8) heat treating to remove moisture and coating from the metal substrate; (9) And (3) nano injection molding, wherein the melting temperature of the resin of the nano injection molding is 200-300 ℃, the temperature of the nano injection molding is 70-90 ℃, the pressure of the injection molding is 70-130 mpa, and the speed of the nano injection molding is 400-900 mm/s.

Wherein the mechanical polishing is selected from polishing to remove nano-scale natural oxide layer on the surface of aluminum or aluminum alloy.

Wherein, an alkaline degreasing agent is used for degreasing, the degreasing agent consists of 30g/L sodium carbonate, 30g/L trisodium phosphate, 15g/L sodium silicate and deionized water, and the treatment temperature is 50 ^o And C, treating for 0.5h.

Further, the surface is coated with polystyrene with a corrosion-resistant coating, the coating mode is spraying, and the thickness of the coating is 10 mu m.

Further, grooves obtained by laser are regularly and uniformly distributed on a metal substrate containing a coating, the aperture of the grooves is 50 μm, the depth of the grooves is greater than or equal to 10 μm so as to expose the metal of the substrate, parameters of laser grooving are as follows: the current is 5-10A, and the frequency is 2-4KHz.

Further, the process of electrochemical corrosion of the macropores is as follows: taking pre-corroded metal as an anode, graphite as a cathode, and simultaneously soaking in a mixed corrosive liquid, connecting a direct-current power supply, wherein the mixed corrosive liquid comprises 2wt.% hydrochloric acid, 0.75wt.% sulfuric acid, 0.5wt.% oxalic acid and 0.12 wt wt.% AlCl ₃ The solution is assisted by ultrasonic treatment in the direct current power-on corrosion process, the ultrasonic frequency is 60KHz, and the temperature is 35 ^o C, time 4min, current density 100mA/cm ² Then washing with pure water, and obtaining corrosion macropores with the same size as the pore diameter of the groove, wherein the pore diameter of the macropores is 50 mu m, and the depth is 10-90 mu m.

Further, freeze-drying: will be electrochemically decayedThe etched metal substrate is placed at a temperature of less than 0 ^o C, placing in a freezer or refrigerator for 3h, and then placing in a freeze dryer, wherein the cold trap temperature is-50 ℃ under vacuum degree of less than 10 Pa ^o C, freeze-drying 3h under the condition of C, and removing the moisture in the holes.

Further, the process of chemically corroding the mesoporous comprises the steps of soaking a freeze-dried metal matrix in T liquid, and corroding to form chemically corroding the chemically corroding mesoporous on the pore wall of the macroporous, wherein the main component of the T liquid is lipomine, the soaking time is 1h, and the soaking temperature is 35 ^o And C, the mesoporous pore diameter range of chemical corrosion is 2-40nm.

Further, the heat treatment steps are as follows: placing the chemically etched metal substrate in a volume fraction of 3%H ₂ /N ₂ The temperature programming is carried out in the mixed atmosphere, and the temperature programming process is 15 ^o C/min up to 160 ^o C, incubation time 1h, then 5 ^o C/min up to 365 ^o C, incubation time 2h, then 20 ^o C/min up to 500 ^o And C, keeping the temperature for 0.5h, and purging the mixed gas to room temperature.

The final nano injection product was designated as S-3.

Example 4

PPS nano injection molding was performed on the high pore density metal substrate obtained in example 2.

The specific steps are as follows, as shown in figures 7-9:

(1) Mechanically polishing; (2) chemical degreasing; (3) anodic oxidation to obtain anodic oxidation mesopores; (4) coating a corrosion-resistant coating on the surface; (5) laser engraving grooves to expose aluminum or aluminum alloy metal; (6) Electrochemical corrosion is carried out on the part exposed out of aluminum or aluminum alloy metal to obtain macropores; (7) freeze-drying; (8) chemical etching to obtain chemical etching mesopores; (9) heat treating to remove moisture and coating from the metal substrate; (10) And (3) nano injection molding, wherein the melting temperature of the resin of the nano injection molding is 200-300 ℃, the temperature of the nano injection molding is 70-90 ℃, the pressure of the injection molding is 70-130 mpa, and the speed of the nano injection molding is 400-900 mm/s.

Further, mechanical polishing is a polishing method to remove the nano-scale natural oxide layer on the surface of aluminum or aluminum alloy.

Further, an alkaline degreasing agent is used for degreasing, the degreasing agent consists of 30g/L sodium carbonate, 30g/L trisodium phosphate, 15g/L sodium silicate and deionized water, and the treatment temperature is 50 ^o C, the treatment time is 0.5h;

further, the step of anodic oxidation is as follows: aluminum or aluminum alloy is used as an anode, inert metal or graphite is used as a cathode, an anodic oxidation solution is 15wt.% of mixed acid aqueous solution, the mixed acid is sulfuric acid and oxalic acid, and the mass ratio of the sulfuric acid to the oxalic acid is (1.2): 1, an operating voltage of 20V, a temperature of 25 ^o C, the time is 1.5h, and the anodic oxidation forms 10-90nm mesoporous on the surface of aluminum or aluminum alloy.

Further, grooves obtained by laser are regularly and uniformly distributed on a metal substrate containing a coating, the aperture of the grooves is 50 μm, the depth of the grooves is more than 10 μm so as to expose the metal of the substrate, parameters of laser grooving are as follows: the current is 5-10A, and the frequency is 2-4KHz.

Further, freeze-drying: placing the electrochemically corroded metal substrate at a temperature lower than 0 DEG C ^o C, placing in a freezer or refrigerator for 3h, and then placing in a freeze dryer, wherein the cold trap temperature is-50 ℃ under vacuum degree of less than 10 Pa ^o C, freeze-drying 3h under the condition of C, and removing the moisture in the holes.

Further, the mesoporous chemical etching process is to coolSoaking the lyophilized metal matrix in T liquid containing lipomine as main component for 1 hr at a soaking temperature of 35 deg.C, and forming chemically etched mesoporous on the macroporous wall by corrosion ^o And C, the mesoporous pore diameter range of chemical corrosion is 2-40nm.

The final nano injection product was designated as S-4.

Comparative example 1

The method comprises the following specific steps:

(1) Mechanically polishing; (2) chemical degreasing; (3) electrochemical corrosion to obtain macropores; (4) freeze-drying; (5) chemically corroding to obtain mesopores; (6) heat treatment; (9) Nano injection molding PPS, wherein the melting temperature of the resin of the nano injection molding is 200-300 ℃, the temperature of the nano injection molding is 70-90 ℃, the pressure of the injection molding is 70-130 mpa, and the speed of the nano injection molding is 400-900 mm/s.

Further, the heat treatment steps are as follows: placing the metal substrate subjected to chemical corrosion into an air drying oven for programmed temperature rise, wherein the programmed temperature rise process is 15 ^o C/min up to 150 ^o And C, preserving the heat for 4 hours, and naturally cooling to room temperature.

Further, the mechanical polishing is selected from polishing to remove nano-scale native oxide layers on the surface of aluminum or aluminum alloy.

Further, an alkaline degreasing agent is used for degreasing, the degreasing agent consists of 30g/L sodium carbonate, 30g/L trisodium phosphate, 15g/L sodium silicate and deionized water, and the treatment temperature is 50 ^o And C, treating for 0.5h.

Further, electrochemical corrosion is largeThe process of the hole is as follows: taking pre-corroded metal as an anode, graphite as a cathode, and simultaneously soaking in a mixed corrosive liquid, connecting a direct-current power supply, wherein the mixed corrosive liquid comprises 2wt.% hydrochloric acid, 0.75wt.% sulfuric acid, 0.5wt.% oxalic acid and 0.12 wt wt.% AlCl ₃ The solution is assisted by ultrasonic treatment in the direct current power-on corrosion process, the ultrasonic frequency is 60KHz, and the temperature is 35 ^o C, time 4min, current density 100mA/cm ² Then, the mixture was washed with pure water.

Further, freeze-drying: placing the electrochemically corroded metal substrate at a temperature lower than 0 DEG C ^o C, placing in a freezer or refrigerator for 3h, and then placing in a freeze dryer, wherein the cold trap temperature is-50 ℃ under vacuum degree of less than 10 Pa ^o C, freeze-drying 3 h under the condition of C, and removing the moisture in the holes.

Further, the process of chemically corroding the mesoporous comprises the steps of soaking a freeze-dried metal matrix in T liquid, and corroding to form chemically corroding the chemically corroding mesoporous on the pore wall of the macroporous, wherein the main component of the T liquid is lipomine, the soaking time is 1h, and the soaking temperature is 35 ^o C。

The final nano injection product was designated as D-1.

Comparative example 2

The method comprises the following specific steps:

(1) Mechanically polishing; (2) chemical degreasing; (3) coating the surface with a corrosion-resistant coating; (4) laser engraving grooves to expose aluminum or aluminum alloy metal; (5) Electrochemical corrosion is carried out on the part exposed out of aluminum or aluminum alloy metal to obtain macropores; (6) freeze-drying; (7) chemically corroding to obtain mesopores; (8) heat treatment; (9) And (3) nano injection molding, wherein the melting temperature of the resin of the nano injection molding is 200-300 ℃, the temperature of the nano injection molding is 70-90 ℃, the pressure of the injection molding is 70-130 mpa, and the speed of the nano injection molding is 400-900 mm/s.

Wherein, an alkaline degreasing agent is used for degreasing, the degreasing agent consists of 30g/L sodium carbonate, 30g/L trisodium phosphate, 15g/L sodium silicate and deionized water, and the treatment temperature is 50 ^o C, processingTime 0.5h.

The final nano injection product was designated as D-2.

Comparative example 3

The method comprises the following specific steps:

(1) Mechanically polishing; (2) chemical degreasing; (3) electrochemical corrosion; (4) freeze-drying; (5) chemically corroding to obtain mesopores; (7) heat treating to remove moisture and coating from the metal substrate; (8) And (3) nano injection molding, wherein the melting temperature of the resin of the nano injection molding is 200-300 ℃, the temperature of the nano injection molding is 70-90 ℃, the pressure of the injection molding is 70-130 mpa, and the speed of the nano injection molding is 400-900 mm/s.

Further, the process of electrochemical corrosion of the macropores is as follows: taking pre-corroded metal as an anode, graphite as a cathode, and simultaneously soaking in a mixed corrosive liquid, connecting a direct-current power supply, wherein the mixed corrosive liquid comprises 2wt.% hydrochloric acid, 0.75wt.% sulfuric acid, 0.5wt.% oxalic acid and 0.12 wt wt.% AlCl ₃ The solution is assisted by ultrasonic treatment in the direct current power-on corrosion process, the ultrasonic frequency is 60KHz, and the temperature is 35 ^o C, time 4min, current density 100mA/cm ² 。

The final nano injection product was designated as D-3.

In addition, the influence of water on the nano injection molding material is tested through stability, but the influence of water vapor on the nano injection molding material or the nano injection molding electronic terminal is tested under the conventional condition, the test period can be more than 5 years, and the influence of the water content on the nano injection molding material is not easy to induce, so that the material test condition is improved. Firstly, carrying out peel strength test on the prepared nano injection molding material S-3, S-4, D-1, D-2, D-3, as shown in table 1, and then placing the S-3, S-4, D-1, D-2, D-3 aluminum alloy in an air drying oven, wherein the temperature of the drying oven is 70-80 ^o And C, the relative humidity is 10-20%, the time is 30 days, the product is taken out to room temperature, and the peeling strength is tested, as shown in Table 2.

Table 1 nano injection molded PPS resin peel strength table.

Table 2 table of PPS stability analysis by nano injection molding.

From the above table, the following can be concluded.

(1) And because anodic mesoporous is introduced below the coating, PPS and the base material are fully contacted, namely the peeling strength of PPS S-4 injection molded on the high-pore-density metal material is higher than that of the low-pore-density S-3, and because the pore density is obviously improved, the standard deviation and the volatility of the PPS-4 injection molded nano injection molded material are smaller, namely the high-pore-density metal base material is more beneficial to preparing nano injection molded materials with consistent performance, and the probability of occurrence of defective products is reduced.

(2) As the uniform macropores are introduced, the contact surface (namely the contact position of the PPS and the pore canal) of the PPS and the substrate is uniform, namely the fluctuation of the product is small, if the uniform template is not suitable for preparing the uniformly distributed macropores, the fluctuation of the nano injection molding metal substrate is larger, for example, compared with S-3 and D-1 and D-3.

(3) If the excess free or bound moisture in the channels is not effectively removed (which would reduce the contact area of the injection molding resin with the channels), the binding force and fluctuation are greater, for example, S-3 is compared with D-1 and D-2.

(4) The temperature of the drying box is 70-80% by placing the drying box in an air drying box ^o And C, the relative humidity is 10-20%, after the sample is left for 30 days, the binding force of all samples is reduced, the aging of PPS can be reduced, but the main reason is that the water in the pore canal is evaporated, so that the peeling strength is obviously reduced, if a proper heat treatment means is used, the influence of the water on the nano injection molding material can be obviously reduced, for example, the S-3, S-4 and D-3 of the table 1 are compared with the S-3, S-4 and D-3 of the table 2, and if only part of free water or water in a macropore is removed, the binding force is reduced, and the long-term stability of the nano injection molding material is also influenced, for example, the D-1 and D-2 of the table 1 are compared with the D-1 and D-2 of the table 2.

Although the present utility model has been described by way of example with reference to the preferred embodiments, the present utility model is not limited to the specific embodiments, and may be modified appropriately within the scope of the present utility model.

Claims

1. A method for preparing an aluminum or aluminum alloy material with high pore density, which is characterized by comprising the following steps:

(1) Mechanically polishing; (2) chemical degreasing; (3) anodic oxidation to obtain anodic oxidation mesopores; (4) coating a corrosion-resistant coating on the surface; (5) laser engraving grooves to expose aluminum or aluminum alloy metal; (6) Electrochemical corrosion is carried out on the part exposed out of aluminum or aluminum alloy metal to obtain macropores; (7) freeze-drying; (8) chemical etching to obtain chemical etching mesopores; (7) heat treating to remove moisture and coating from the metal substrate; finally obtainThe pore density of the surface of the aluminum or aluminum alloy is 10 ⁸ -10 ¹⁰ Individual/cm ² The water content of the surface of the aluminum or aluminum alloy is lower than 30mg/m ² ；

Grooves obtained by laser etching are regularly and uniformly distributed on a metal substrate containing a coating, the aperture of the grooves is 1-200 mu m, the depth of the grooves is larger than the sum of the thicknesses of the surface coated corrosion-resistant coating and the anodic oxidation layer so as to expose the metal of the substrate, and parameters of the grooves are used for conducting electricity and laser etching: the current is 5-10A, the frequency is 2-4KHz;

The anodic oxidation step is as follows: aluminum or aluminum alloy is used as an anode, inert metal or graphite is used as a cathode, an anodic oxidation solution is 10-20wt.% of mixed acid aqueous solution, the mixed acid is sulfuric acid and oxalic acid, and the mass ratio of the sulfuric acid to the oxalic acid is (1-1.5): 1, operating voltage is 10-30V, temperature is 20-30 ℃, time is 1-2 hours, and 10-90nm mesopores are formed on the surface of aluminum or aluminum alloy by anodic oxidation;

the heat treatment process comprises the following steps: under the normal temperature condition, the temperature is raised to 160 ℃ at 15 ℃/min, the heat preservation time is 0.5-2 h, then raised to 365 ℃ at 5 ℃/min, the heat preservation time is 2-3 h, then raised to 500 ℃ at 20 ℃/min, the heat preservation time is 0.5-1 h, and the mixed gas is purged and cooled to the room temperature.

2. The method for preparing the aluminum or aluminum alloy material with high pore density according to claim 1, wherein the mechanical polishing is one of polishing, barreling, sand blasting or shot blasting, removing a nanoscale natural oxide layer on the surface of the aluminum or aluminum alloy, and the chemical degreasing is an acidic or alkaline degreasing agent, wherein the alkaline degreasing agent consists of 30g/L sodium carbonate, 30g/L trisodium phosphate, 15g/L sodium silicate and deionized water, and the treatment temperature is 50 ℃; or acidic degreasing pretreatment, wherein the acidic degreasing agent consists of 100ml/L of d=1.84 sulfuric acid, 25g/L of OP emulsifier and deionized water, and the treatment temperature is room temperature.

3. The method of producing a high pore density aluminum or aluminum alloy material as claimed in claim 1, wherein the corrosion resistant coating is selected from the group consisting of polyvinyl chloride, polystyrene, polyethylene, polypropylene, and polyamide.

4. The method for preparing high-pore-density aluminum or aluminum alloy material as claimed in claim 1, wherein aluminum or aluminum alloy obtained by laser etching is used as an anode, inert metal or graphite is used as a cathode, and the aluminum or aluminum alloy material is immersed in a mixed corrosive liquid, and is connected with a direct current power supply, wherein the mixed corrosive liquid comprises 1-3 wt.% hydrochloric acid, 0.5-1 wt.% sulfuric acid, 0.2-1 wt.% oxalic acid and 0.1-0.15 wt.% AlCl ₃ The solution is subjected to ultrasonic treatment assisted by Direct Current (DC) power-on corrosion, the ultrasonic frequency is 40-100 KHz, the temperature is 30-40 ℃, the time is 3-5 min, and the current density is 50-200mA/cm ² The pore diameter of the obtained macropores is consistent with the pore diameter of the laser engraving groove, the range is 1-200 mu m, and the pore depth of the macropores is 10-90 mu m.

5. The method for preparing a high pore density aluminum or aluminum alloy material as claimed in claim 1, wherein the step of freeze-drying is: and (3) placing the electrochemically corroded metal substrate in a refrigerator or a freezer with the temperature lower than 0 ℃ for 0.5-5 h, then placing in a freeze dryer, and freeze-drying for 0.5-5 h under the condition that the vacuum degree is lower than 10 Pa and the cold trap temperature is-50 ℃ to remove water in the holes.

6. The method for preparing a high pore density aluminum or aluminum alloy material as claimed in claim 1, wherein the step of chemically etching is: and freeze-drying the aluminum or aluminum alloy obtained through electrochemical corrosion, and then soaking the aluminum or aluminum alloy in a T liquid, wherein the components of the T liquid contain lipomine, the soaking time is 0.5-2 h, the soaking temperature is 20-50 ℃, and the mesoporous pore diameter range of chemical corrosion is 2-40nm.

7. A method of producing a high pore density aluminum or aluminum alloy material as claimed in claim 1, wherein said heat treatment is capable of simultaneously removing moisture and corrosion resistant coating.