CN116809923A - Preparation method of MIM (metal-insulator-metal) feed with low surface roughness - Google Patents
Preparation method of MIM (metal-insulator-metal) feed with low surface roughness Download PDFInfo
- Publication number
- CN116809923A CN116809923A CN202310766173.3A CN202310766173A CN116809923A CN 116809923 A CN116809923 A CN 116809923A CN 202310766173 A CN202310766173 A CN 202310766173A CN 116809923 A CN116809923 A CN 116809923A
- Authority
- CN
- China
- Prior art keywords
- feed
- stainless steel
- surface roughness
- mim
- steel powder
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- 238000002360 preparation method Methods 0.000 title claims abstract description 10
- 230000003746 surface roughness Effects 0.000 title claims description 17
- 239000002184 metal Substances 0.000 title abstract description 10
- 239000000843 powder Substances 0.000 claims abstract description 32
- 229910001220 stainless steel Inorganic materials 0.000 claims abstract description 26
- 239000010935 stainless steel Substances 0.000 claims abstract description 26
- 238000000034 method Methods 0.000 claims abstract description 22
- 239000011230 binding agent Substances 0.000 claims abstract description 18
- 238000002156 mixing Methods 0.000 claims abstract description 18
- 239000002245 particle Substances 0.000 claims abstract description 15
- 238000009826 distribution Methods 0.000 claims abstract description 6
- 239000000853 adhesive Substances 0.000 claims description 19
- 230000001070 adhesive effect Effects 0.000 claims description 19
- 238000010438 heat treatment Methods 0.000 claims description 7
- XKRFYHLGVUSROY-UHFFFAOYSA-N Argon Chemical compound [Ar] XKRFYHLGVUSROY-UHFFFAOYSA-N 0.000 claims description 6
- 238000003825 pressing Methods 0.000 claims description 5
- 239000000155 melt Substances 0.000 claims description 4
- 229910052786 argon Inorganic materials 0.000 claims description 3
- 239000003795 chemical substances by application Substances 0.000 claims description 2
- 238000013329 compounding Methods 0.000 claims 1
- 238000002347 injection Methods 0.000 abstract description 16
- 239000007924 injection Substances 0.000 abstract description 16
- 238000001746 injection moulding Methods 0.000 abstract description 16
- 238000005461 lubrication Methods 0.000 abstract description 2
- 239000000047 product Substances 0.000 description 14
- RKISUIUJZGSLEV-UHFFFAOYSA-N n-[2-(octadecanoylamino)ethyl]octadecanamide Chemical compound CCCCCCCCCCCCCCCCCC(=O)NCCNC(=O)CCCCCCCCCCCCCCCCC RKISUIUJZGSLEV-UHFFFAOYSA-N 0.000 description 12
- 238000005245 sintering Methods 0.000 description 8
- 230000000052 comparative effect Effects 0.000 description 6
- 238000000465 moulding Methods 0.000 description 5
- 239000004033 plastic Substances 0.000 description 5
- 229920003023 plastic Polymers 0.000 description 5
- 238000005516 engineering process Methods 0.000 description 4
- 229930040373 Paraformaldehyde Natural products 0.000 description 3
- 239000005038 ethylene vinyl acetate Substances 0.000 description 3
- 229920001200 poly(ethylene-vinyl acetate) Polymers 0.000 description 3
- -1 polyoxymethylene Polymers 0.000 description 3
- 229920006324 polyoxymethylene Polymers 0.000 description 3
- 238000012360 testing method Methods 0.000 description 3
- 239000004698 Polyethylene Substances 0.000 description 2
- 239000004743 Polypropylene Substances 0.000 description 2
- CQEYYJKEWSMYFG-UHFFFAOYSA-N butyl acrylate Chemical compound CCCCOC(=O)C=C CQEYYJKEWSMYFG-UHFFFAOYSA-N 0.000 description 2
- 238000005238 degreasing Methods 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 238000002474 experimental method Methods 0.000 description 2
- 239000012467 final product Substances 0.000 description 2
- 238000005469 granulation Methods 0.000 description 2
- 230000003179 granulation Effects 0.000 description 2
- 239000000203 mixture Substances 0.000 description 2
- 238000004663 powder metallurgy Methods 0.000 description 2
- 239000007787 solid Substances 0.000 description 2
- 239000000126 substance Substances 0.000 description 2
- VGGSQFUCUMXWEO-UHFFFAOYSA-N Ethene Chemical compound C=C VGGSQFUCUMXWEO-UHFFFAOYSA-N 0.000 description 1
- 239000005977 Ethylene Substances 0.000 description 1
- 239000012752 auxiliary agent Substances 0.000 description 1
- 238000002144 chemical decomposition reaction Methods 0.000 description 1
- 239000003153 chemical reaction reagent Substances 0.000 description 1
- 229920001577 copolymer Polymers 0.000 description 1
- 238000005336 cracking Methods 0.000 description 1
- 230000003247 decreasing effect Effects 0.000 description 1
- 238000000280 densification Methods 0.000 description 1
- 238000013461 design Methods 0.000 description 1
- 238000001514 detection method Methods 0.000 description 1
- 238000007599 discharging Methods 0.000 description 1
- 239000002270 dispersing agent Substances 0.000 description 1
- 238000001125 extrusion Methods 0.000 description 1
- 238000011049 filling Methods 0.000 description 1
- 230000009969 flowable effect Effects 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- 238000002844 melting Methods 0.000 description 1
- 230000008018 melting Effects 0.000 description 1
- 238000003921 particle size analysis Methods 0.000 description 1
- 238000011056 performance test Methods 0.000 description 1
- 229920000573 polyethylene Polymers 0.000 description 1
- 229920001155 polypropylene Polymers 0.000 description 1
- 239000002994 raw material Substances 0.000 description 1
- 230000036186 satiety Effects 0.000 description 1
- 235000019627 satiety Nutrition 0.000 description 1
- 238000007711 solidification Methods 0.000 description 1
- 230000008023 solidification Effects 0.000 description 1
- 239000000243 solution Substances 0.000 description 1
- 238000010998 test method Methods 0.000 description 1
- 238000005979 thermal decomposition reaction Methods 0.000 description 1
- 229920001169 thermoplastic Polymers 0.000 description 1
- 239000004416 thermosoftening plastic Substances 0.000 description 1
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B22—CASTING; POWDER METALLURGY
- B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
- B22F1/00—Metallic powder; Treatment of metallic powder, e.g. to facilitate working or to improve properties
- B22F1/10—Metallic powder containing lubricating or binding agents; Metallic powder containing organic material
- B22F1/103—Metallic powder containing lubricating or binding agents; Metallic powder containing organic material containing an organic binding agent comprising a mixture of, or obtained by reaction of, two or more components other than a solvent or a lubricating agent
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B22—CASTING; POWDER METALLURGY
- B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
- B22F1/00—Metallic powder; Treatment of metallic powder, e.g. to facilitate working or to improve properties
- B22F1/05—Metallic powder characterised by the size or surface area of the particles
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B22—CASTING; POWDER METALLURGY
- B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
- B22F1/00—Metallic powder; Treatment of metallic powder, e.g. to facilitate working or to improve properties
- B22F1/10—Metallic powder containing lubricating or binding agents; Metallic powder containing organic material
- B22F1/108—Mixtures obtained by warm mixing
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B22—CASTING; POWDER METALLURGY
- B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
- B22F3/00—Manufacture of workpieces or articles from metallic powder characterised by the manner of compacting or sintering; Apparatus specially adapted therefor ; Presses and furnaces
- B22F3/22—Manufacture of workpieces or articles from metallic powder characterised by the manner of compacting or sintering; Apparatus specially adapted therefor ; Presses and furnaces for producing castings from a slip
- B22F3/225—Manufacture of workpieces or articles from metallic powder characterised by the manner of compacting or sintering; Apparatus specially adapted therefor ; Presses and furnaces for producing castings from a slip by injection molding
Landscapes
- Chemical & Material Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Engineering & Computer Science (AREA)
- Manufacturing & Machinery (AREA)
- Mechanical Engineering (AREA)
- Powder Metallurgy (AREA)
Abstract
The invention belongs to the technical field of metal powder injection molding, and particularly relates to a preparation method of a low-surface-roughness MIM (metal injection molding) feed. The method comprises the following steps: mixing stainless steel powder and binder, adding EBS, mixing for 3-6min, and granulating with particle size distribution D50 of 4-5 μm. According to the technical scheme provided by the invention, through a combined lubrication system and a preparation process of the feed, even under the condition of greatly reducing the particle size, the necessary fluidity of the feed in the injection process, the saturation degree of injection and the light flow mark can be ensured, and finally, the MIM product with Ra less than 0.5 can be successfully prepared.
Description
Technical Field
The invention belongs to the technical field of metal powder injection molding, and particularly relates to a preparation method of a low-surface-roughness MIM (metal injection molding) feed.
Background
The metal powder injection molding technology (MIM) is a novel near net forming technology of powder metallurgy, which is formed by introducing the modern plastic injection molding technology into the field of powder metallurgy. The process comprises the following steps: firstly, uniformly mixing solid powder and an organic binder, granulating, injecting into a die cavity by an injection molding machine in a heating plasticizing state for solidification molding, removing the binder in a molding blank by a chemical or thermal decomposition method, and finally sintering and densification to obtain a final product. The metal injection molding technology is a better method for manufacturing small, complex-shape and high-strength parts in large quantities.
The feed for injection molding of metal powder means a raw material for injection molding after mixing solid powder with an organic binder, so that the main physical and chemical properties of the final product are mainly determined by the feed. The grain size of the prior MIM stainless steel feed is generally D50:9-11 mu m, the feed with the grain size can be smoothly molded in the subsequent injection molding process, but the surface roughness after sintering can only reach Ra:1.0-1.3.
As the product is upgraded, the surface roughness of the product after sintering is required to be further reduced to Ra < 0.5. The feed reduces the surface roughness of the sintered product only by reducing the particle size of the feed. Experiments prove that when Ra is less than 0.5, the grain size of the feed is at least reduced to D50:4-5 mu m, but the reduction of the grain size of the feed brings the problems of high injection pressure, heavy flow marks, difficult satiety and the like for subsequent injection molding, and the molding of products is directly influenced, so that the feed needs to be optimized to solve the problems.
The high injection pressure, heavy flow marks and poor filling are all related to poor flowability of the feed due to reduced particle size. The injection feed is divided into a plastic base system and a wax base system by the main components of the binder, the fluidity of the wax base system is good, the follow-up degreasing time is very long, the deformation in the degreasing process is large, and the product is easy to generate flash, so that the plastic base system is generally adopted by MIM except for some specific cases at present. To improve the flowability of the injection-molding feed of plastic-based systems, this is mainly achieved by means of binders, i.e. by increasing the melt flow index of the POM (polyoxymethylene) which is the main component in the binder, if POM alone by using high melt index is too costly on the one hand and the rise is not significant on the other hand.
The Chinese patent CN109513916A has the advantage that the components and the auxiliary agents in the adhesive can be well compatible and flowable by adding the compatilizer. However, the D50 in the particle size distribution of the feed is still as high as 9.8-10.8, and is not suitable.
The particle size of the feed in Chinese patent CN114210979A is 7-9 mu m, and the feed has good fluidity through customized allocation and argon protection of a binder system, so that the particle size of the feed is still far higher than that of D50:4-5 mu m.
Disclosure of Invention
The invention provides a preparation method of a low-surface-roughness MIM (metal-insulator-metal) feed, which is used for solving the problem that the low-particle-size feed prepared at present cannot be processed through MIM.
In order to solve the technical problems, the technical scheme of the invention is as follows: the preparation method of the low surface roughness MIM feed comprises the following steps: mixing stainless steel powder and binder, adding EBS (ethylene bis stearamide), mixing for 3-6min, and granulating with particle size distribution of 4-5 μm.
EBS can effectively improve the fluidity of the feed in injection molding, but if the mixing time is long, volatilization cracking is generated to lose efficacy, and if the EBS is directly mixed with the feed for injection molding without mixing, on the one hand, the uniformity is poor, and the effect of improving the fluidity of the EBS cannot be fully exerted.
Alternatively, the EBS is added in an amount of 5-20% wt, preferably 7-9% wt, of the binder. The EBS is added less, the required injection fluidity cannot be obtained, and excessive addition can lead to uneven injection and unstable injection pressure, thereby affecting the molding effect of the product.
Optionally, the adhesive comprises the following components in parts by weight:
alternatively, the backbone agent is PE (polyethylene), PP (polypropylene), EVA (ethylene-vinyl acetate copolymer) or EBA (binary copolymer of ethylene (E) and Butyl Acrylate (BA)), preferably EBA.
Compared with EVA, the EBA has better compatibility with other EBS, and the same addition amount can more effectively improve the fluidity and the ejection pressure of the feed.
Optionally, the shrinkage of the product after feed injection molding is 1.162-1.168.
The shrinkage rate adopted in the mould design in the MIM industry is generally controlled to be 1.162-1.168, the sintering difficulty of the product produced in the range is controllable, and the strength of the product after sintering is also sufficient.
Optionally, the stainless steel powder and the adhesive are proportioned according to parts by weight as follows:
80-90 parts of stainless steel powder;
10-20 parts of adhesive;
preferably, the stainless steel powder and the adhesive are mixed according to the following weight parts:
86-88 parts of stainless steel powder;
12-14 parts of adhesive.
When the particle size distribution becomes smaller, the shrinkage becomes larger, and the binder ratio needs to be decreased to control the shrinkage to an appropriate level.
Optionally, the stainless steel powder is 316L.
Optionally, the stainless steel powder and binder mixing process is as follows: heating stainless steel powder to 180-185 ℃, controlling the temperature to 165-170 ℃, adding the mixed adhesive, fully mixing the adhesive and the stainless steel powder at the temperature, pressing down a pressing hammer to the bottom, and uniformly mixing the adhesive and the stainless steel powder through pressing hammer extrusion.
Optionally, argon is continuously introduced in the mixing process of the stainless steel powder and the adhesive, and the stainless steel powder and the adhesive are protected by positive pressure.
Alternatively, the melt flow of the feed has an index of 1500-2500g/min, preferably 1800-2200g/min.
Optionally, the bulk density of the feed is greater than 2.8g/cm 3 Tap density of more than 4.8g/cm 3 。
According to the technical scheme provided by the invention, through a combined lubrication system and a preparation process of the feed, even under the condition of greatly reducing the particle size, the necessary fluidity of the feed in the injection process, the saturation degree of injection and the light flow mark can be ensured, and finally, the MIM product with Ra less than 0.5 can be successfully prepared.
Detailed Description
For ease of understanding, the method of preparing the low surface roughness MIM feed is described below in conjunction with examples, which are to be understood as merely illustrative of the invention and are not to be construed as limiting the scope of the invention.
The materials and reagents used in this example are commercially available general products unless otherwise specified. Wherein the EBS is a Huawang brand dispersant, the model is EB-FF, and the melting point (DEG C) is 141.5-146.5.
Examples 1 to 2
The preparation method of the MIM feed with low surface roughness comprises the following steps: heating stainless steel powder to 180-185 ℃, controlling the temperature to 165-170 ℃, adding the mixed adhesive, continuously heating for 10-15min, pressing down to the bottom, mixing for 20-25min, adding EBS, continuously mixing for 3-6min, and discharging and granulating.
The allocation of the groups in the above embodiment is shown in table 1.
TABLE 1
Comparative examples 1 to 3
The difference with the embodiment 1-2 is that the stainless steel powder and the adhesive are directly discharged from the furnace for granulation after being mixed, specifically, the stainless steel powder is heated to 180-185 ℃, then the temperature is controlled to 165-170 ℃, the mixed adhesive is added for continuously heating for 10-15min, then the mixture is pressed down and hammered to the bottom, and the mixture is directly discharged from the furnace for granulation after being mixed for 20-25min.
The allocation of the groups in the above embodiment is shown in table 2.
TABLE 2
Performance experiments
The following performance tests were conducted on examples 1-2 and comparative examples 1-3, and the test results are shown in Table 3:
the powder particle size testing method comprises the following steps: and 5 times of detection are carried out on the same sample by adopting laser particle size analysis measurement, and the experimental result is that the interval where the detected D50 data are located is rounded.
The fluidity test method comprises the following steps: the melt Mass Flow Rate (MFR) and melt volume flow rate (MVR) of the thermoplastic were measured and tested with reference to ISO 1133:2005 plastic.
Shrinkage refers to the ratio of the size of the mold cavity to the size of the product after 24 hours of sinter molding.
The injection pressure is the actual value used on the injection machine.
The method for testing the roughness after sintering comprises the following steps: the surface of the sintered product was inspected 5 times by a contact coarser machine and then averaged.
TABLE 3 Table 3
From examples 1 and 2 in Table 3, it was found that the feed of example 1 had less flowability during injection and no flow marks due to better EBA and EBS compatibility. Comparative example 1 is a performance index of the conventional formula feed with conventional particle size after injection sintering, and the roughness of the feed exceeds 1, so that the requirements of the feed cannot be met, while the particle size distribution in comparative example 2 is reduced to ensure that the final sintering roughness is lower than 0.5, but the fluidity in the injection process is poor, the injection pressure is high, the flow mark is serious, and the product is unqualified. While in comparative example 3, EBS was added together with the binder, although the fluidity and ejection pressure were significantly improved under the condition of reduced particle size, they were still higher than in comparative example 2, and the surface was also slightly flow-marked.
Finally, it should be noted that: the above embodiments are only for illustrating the technical solution of the present invention, and are not limiting. Although the invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical scheme described in the foregoing embodiments may be modified or some or all of the technical features may be replaced with other technical features, which do not depart from the scope of the technical scheme of the embodiments of the present invention.
Claims (9)
1. The preparation method of the MIM feed with low surface roughness is characterized by comprising the following steps of: mixing stainless steel powder and binder, adding EBS, mixing for 3-6min, and granulating with particle size distribution D50 of 4-5 μm.
2. The method of preparing a low surface roughness MIM feed according to claim 1, wherein the EBS is added in an amount of 5-20% wt, preferably 7-9% wt of the binder.
3. The method for preparing the low surface roughness MIM feed according to claim 1, wherein the binder comprises the following components in parts by weight:
4. a method of preparing a low surface roughness MIM feed according to claim 3, wherein the backbone agent is PE, PP, EVA or EBA, preferably EBA.
5. The method for preparing the low surface roughness MIM feed of claim 1, wherein the stainless steel powder and the binder are in the following proportions in parts by weight:
80-90 parts of stainless steel powder;
10-20 parts of adhesive;
preferably, the stainless steel powder and the adhesive are mixed according to the following weight parts:
86-88 parts of stainless steel powder;
12-14 parts of adhesive.
6. The method of producing a low surface roughness MIM feed of claim 1, wherein the stainless steel powder is 316L.
7. The method of preparing a low surface roughness MIM feed of claim 1, wherein the stainless steel powder and binder compounding process is as follows: heating stainless steel powder to 180-185 ℃, controlling the temperature to 165-170 ℃, adding the mixed adhesive, continuously heating for 10-15min, pressing down to the bottom, and mixing for 20-25min.
8. The method for preparing the low surface roughness MIM feed of claim 1, wherein argon is continuously introduced and protected by positive pressure during the mixing process of the stainless steel powder and the adhesive.
9. A method of preparing a low surface roughness MIM feed according to claim 1, wherein the melt flow index of the feed is 1500-2500g/min, preferably 1800-2200g/min.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202310766173.3A CN116809923A (en) | 2023-06-27 | 2023-06-27 | Preparation method of MIM (metal-insulator-metal) feed with low surface roughness |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202310766173.3A CN116809923A (en) | 2023-06-27 | 2023-06-27 | Preparation method of MIM (metal-insulator-metal) feed with low surface roughness |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN116809923A true CN116809923A (en) | 2023-09-29 |
Family
ID=88117984
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202310766173.3A Pending CN116809923A (en) | 2023-06-27 | 2023-06-27 | Preparation method of MIM (metal-insulator-metal) feed with low surface roughness |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN116809923A (en) |
-
2023
- 2023-06-27 CN CN202310766173.3A patent/CN116809923A/en active Pending
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US10544294B2 (en) | Binder for injection moulding compositions | |
| EP2409797B1 (en) | Injection molding composition | |
| CN104227003A (en) | Preparation method of powder injection molded feeding material | |
| JP5439194B2 (en) | Organic binder manufacturing method and organic binder | |
| US20110248422A1 (en) | Method for producing cemented carbide or cermet products | |
| US20130200556A1 (en) | Method for producing cemented carbide products | |
| CN110204334A (en) | A kind of high-compactness Zirconium oxide powder injection moulding PP Pipe Compound and preparation method thereof | |
| US9403212B2 (en) | Process for producing components by powder injection molding | |
| KR101761649B1 (en) | Metal powder-containing composition for three dimensional printing | |
| KR101916495B1 (en) | Process for producing components by powder injection molding | |
| US11718736B2 (en) | Binder for injection moulding compositions | |
| US5332543A (en) | Method for producing articles from particulate materials using a binder derived from an idealized TGA curve | |
| CN109926589A (en) | The injection moulding method and mold of ultra-fine cemented carbide CNC turning tool | |
| CN108115141A (en) | A kind of ejection forming method of Ultra-fine WC-Co Cemented Carbide | |
| CN116809923A (en) | Preparation method of MIM (metal-insulator-metal) feed with low surface roughness | |
| JPH06263524A (en) | Method and molding compound to manufacture inorganic sintered product by injection molding | |
| CN111545758A (en) | Novel 316L feed for low-temperature powder injection molding and preparation process | |
| CN101396734B (en) | Handset vibrator manufacture method | |
| US7303722B2 (en) | Method of making tools or components | |
| KR20110023182A (en) | The date marking method by powder injection molding | |
| CN107755702B (en) | Improved powder injection molding compound, product made therefrom and method of making the product | |
| CN115283662B (en) | Metal injection molding binder, feed and preparation method thereof | |
| EP4036167A1 (en) | Binder composition for metal powder injection molding | |
| CN114210979A (en) | Customized feed and preparation method thereof | |
| KR100340590B1 (en) | Bonding agent for powder injection molding and a method of manufacturing by using it |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination |