CN109628772B

CN109628772B - Ultrashort-period high-strength and high-ductility nickel-aluminum bronze alloy and preparation method thereof

Info

Publication number: CN109628772B
Application number: CN201811592724.4A
Authority: CN
Inventors: 卢文龙; 翟文正; 刘晓军
Original assignee: Huazhong University of Science and Technology
Current assignee: Huazhong University of Science and Technology
Priority date: 2018-12-25
Filing date: 2018-12-25
Publication date: 2020-04-10
Anticipated expiration: 2038-12-25
Also published as: CN109628772A; WO2020133680A1

Abstract

The invention discloses a preparation method of an ultrashort-period high-strength and high-ductility nickel-aluminum bronze alloy, which is characterized by comprising the following steps of: s1, according to Cu: al: ni: fe: the mol ratio of Mn is proportioned to each powder, and the average grain diameter of the powder is 20-60 mu m; mixing the powder materials to obtain a mixture; s2, obtaining a nickel-aluminum bronze bar with the diameter of 50-100mm through smelting, forging and heat treatment processes according to the components of the mixture; s3, atomizing the nickel-aluminum bronze bar by adopting a plasma electrode atomization method; and S4, carrying out 3D printing on the nickel-aluminum bronze alloy powder subjected to the plasma electrode atomization treatment by adopting a selective electron beam melting process to obtain the nickel-aluminum bronze alloy with high density, high strength and high ductility. The alloy prepared by the preparation method disclosed by the invention has the advantages that the internal precipitated phase is fine and is in a uniform dispersion distribution state, the alloy density is high, the high strength and the high ductility are realized, the process parameters in the preparation process are easy to control, and the processing period is short.

Description

Ultrashort-period high-strength and high-ductility nickel-aluminum bronze alloy and preparation method thereof

Technical Field

The invention belongs to the field of nickel-aluminum bronze alloys, and particularly relates to a preparation method of an ultrashort-period high-strength and high-ductility nickel-aluminum bronze alloy and the prepared ultrashort-period high-strength and high-ductility nickel-aluminum bronze alloy.

Background

For a long time, efforts have been made to search for metals and alloys having both high strength and high ductility to meet the demand. While conventional methods generally reduce the ductility of the material while increasing its strength. In recent years, some innovative microstructure designs, including the introduction of High density dislocations in the material texture (see document 1.He, b.b.et al. High dislocation density-induced large reduction for formed and fractional dimensions. science 357,1029(2017), document 2.Lu, l.shen, y.hen, Chen, x.qian, l.lu, k.ultra High Strength and High Electrical Conductivity in coater. science 304,422(2004), Gradient nanocrystalline structures (see document 3.Fang, t.h., Li, w.l., Tao, N.R. & Lu, k.variation expression in microstructure density in difference No. 331-contained in Gradient density in difference, 78, k.variation in microstructure in difference No. 12-37, Gradient in Gradient microstructure (see document 3. bright, t.h., t.331, w.l., Tao, N.R. & Lu), k.variation in density in difference, and High density in grain can effectively overcome the problems described above (see document 1.He, b.b.et al., High dislocation density-induced Gradient in, grain in, No. 7, Gradient in grain, 3. catalogue, 3. 1590, et al. However, these methods are difficult to be applied to machining mechanical parts with complicated geometries, and since the methods require multiple machining processes, the problems of machining repeatability due to the increase of control variables are caused, which is not favorable for the stability of the texture and performance of the manufactured mechanical parts. In recent years, additive manufacturing methods have been desired to solve the above-described challenges by giving high degrees of freedom in design and processing (see document 5.Zheng, x.et. multiscale metallic materials. nature materials.15, 1100 (2016); document 6.Mchugh, k.j.et. publication of fibrous microstructures and other complex 3 microbiological structures. science 357,1138 (2017)). It has been shown that 316L stainless steel manufactured by laser powder melting (L-PBF) technology has both high yield strength and high ductility (see, document 7.Wang, Y.M. et al. additive manufacturing technology with high strength and high ductility. Nature Mat. 17,63-71 (2018); document 8.Sun, Z., Tan, X., Tor, S.B. & Chua, C.K. Simulanesulfonated enhanced strength and ductility for 3D-printed stainless steel 316L by selective. NnAsia Mat. 10 (2018); document 9.Liu, L.et al. discrete processing technology with high ductility. 2018, Mat. 354. 37. Todar. 354. 78). However, the 3D printing technology is currently limited to manufacturing metal materials which are easy to weld, such as stainless steel, titanium alloy, nickel alloy, etc. (see document 10.Martin, j.h. et al.3dprinting of high-strength aluminum alloys. nature 549, 365-. For example, in the production of copper alloys by the L-PBF technique, partial melting occurs, resulting in a relative density of less than 95% (see document 11.Zhang, D.Q., Liu, Z.H. & Chua, C.K. investment on processing of copper alloys in High Value Manufacturing: Advanced Research in visual and Rapid processing of the 6th International conference on Advanced Research in visual and Rapid processing, Leira, Portugal 285 (2013)). The relative density of the obtained Cu-Cr-Zr-Ti alloy reaches 97.9% by regulating and controlling the processing parameters of 3D printing, but the tensile strength (UTS) of the Cu-Cr-Zr-Ti alloy is 20-25% lower than that of the traditional forged forming piece because the internal crystal grain size of the forming piece is mainly columnar crystal of 30-250 μm (see the document 12.Popovich, A.et al. microscopic and mechanical properties of additive manufactured copper alloy. Mater. Lett.179,38-41 (2016)).

Selective Electron Beam Melting (SEBM) is one of the key technologies for metal 3D printing fabrication, which manufactures parts by selectively sintering metal powder under high vacuum using electron beams. Compared with Selective Laser Melting (SLM), the SEBM technology can provide a more uniform heating environment and higher energy density when 3D printing copper alloy, and overcomes the problem of low energy absorption rate of the copper alloy in the SLM technology. Meanwhile, compared with the traditional method for manufacturing the copper alloy part (blanking-annealing-stamping forming-annealing-passivating, and sometimes multiple stamping processing and repeated annealing are needed), the SEBM technology can be used for forming the nickel-aluminum bronze alloy part at one time, the density is close to complete compactness, the relative density is more than 99%, the mechanical properties (including tensile strength and tensile elongation) are superior to those of similar products manufactured by a forging process, and the SEBM technology has the advantages of short processing period and high efficiency.

Disclosure of Invention

Aiming at least one of the defects or improvement requirements in the prior art, the invention provides a preparation method of an ultrashort-period high-strength and high-ductility nickel-aluminum bronze alloy, the internal precipitated phase of the obtained alloy is fine and is in a uniform dispersion distribution state, the alloy has high density, high strength and high ductility, the technological parameters in the preparation process are easy to control, and the processing period is short.

In order to achieve the above object, according to one aspect of the present invention, there is provided a method for preparing an ultrashort-period high-strength high-ductility nickel aluminum bronze alloy, comprising the steps of:

s1, according to Cu: al: ni: fe: mn molar ratio ═ (remainder): (8-12): (3.5-6.5): (2.5-5.5): (0.8-1.2), selecting Cu powder, Al powder, Ni powder, Fe powder and Mn powder, wherein the average grain diameter of the powder is 20-60 mu m; mixing Cu powder, Al powder, Ni powder, Fe powder and Mn powder to obtain a mixture;

s2, obtaining a nickel-aluminum bronze bar with the diameter of 50-100mm through smelting, forging and heat treatment processes according to the components of the mixture;

s3, atomizing the nickel-aluminum bronze bar by adopting a plasma electrode atomization method;

and S4, carrying out 3D printing on the nickel-aluminum bronze alloy powder subjected to the plasma electrode atomization treatment by adopting a selective electron beam melting process to obtain the nickel-aluminum bronze alloy with high density, high strength and high ductility.

Preferably, in step S1, Cu: al: ni: fe: molar ratio of Mn 81.1: 9.5: 4.2: 4.0: 1.2.

preferably, the melting process in step S2 is performed in a high-purity argon or nitrogen environment.

Preferably, the plasma electrode atomization process in step S3 is performed in a high-purity argon or nitrogen atmosphere.

Preferably, in step S3, the process conditions of the plasma electrode atomization process are as follows: the rotating speed of the electrode rod is 15000-30000r/min, and the diameter of the electrode rod is 50-100 mm.

Preferably, in step S4, the selective electron beam melting process conditions are:

the preheating temperature of the 3D printing bottom plate is 400-800 ℃, and the 3D printing scanning speed is 20-50 m/s; the printing scanning speed is 0.5-1m/s, the single-layer scanning adopts a reciprocating mode, the interlayer rotation angle is 0-90 degrees, the filling distance is 0.15mm, the scanning electron beam current is 2-5mA, and the diameter range of the plasma electrode atomized spherical powder is 45-105 μm.

In order to achieve the above object, according to an aspect of the present invention, there is also provided a high-strength and high-ductility nickel aluminum bronze alloy obtained by applying the preparation method as described above, wherein the nickel aluminum bronze alloy has a tensile strength of 900MPa or more, preferably 960MPa or more, a uniform elongation of 30% or more, and a relative compactness of 99% or more.

The above-described preferred features may be combined with each other as long as they do not conflict with each other.

Generally, compared with the prior art, the above technical solution conceived by the present invention has the following beneficial effects:

1. according to the preparation method of the ultrashort-period high-strength and high-ductility nickel-aluminum bronze alloy, the precipitated phase of the prepared nickel-aluminum bronze alloy is uniformly and dispersedly distributed, and the defect that the mechanical property is reduced due to nonuniform dispersion of the precipitated phase caused by the traditional preparation process is overcome;

2. the nickel-aluminum bronze alloy prepared by the preparation method of the ultrashort-period high-strength and high-ductility nickel-aluminum bronze alloy has high density and excellent mechanical property.

3. The preparation method of the ultrashort-period high-strength and high-ductility nickel-aluminum bronze alloy has a simple preparation process, can realize the rapid and low-cost preparation of workpieces with complex structures, and can theoretically prepare nickel-aluminum bronze parts with any complex structures within the allowable range of the size of 3D printing equipment.

4. The preparation method of the ultrashort-period high-strength and high-ductility nickel-aluminum bronze alloy adopts a selective electron beam melting process (SEBM), and metal powder is selectively sintered by using electron beams under high vacuum to manufacture parts. Compared with Selective Laser Melting (SLM), the SEBM technology can provide a more uniform heating environment and higher energy density when 3D printing copper alloy, and overcomes the problem of low energy absorption rate of the copper alloy in the SLM technology. Meanwhile, compared with the traditional method for manufacturing the copper alloy part (blanking-annealing-stamping forming-annealing-passivating, and sometimes multiple stamping processing and repeated annealing are needed), the SEBM technology can be used for forming the nickel-aluminum bronze alloy part at one time, the density is close to complete compactness, the relative density is more than 99%, the mechanical properties (including tensile strength and tensile elongation) are superior to those of similar products manufactured by a forging process, and the SEBM technology has the advantages of short processing period and high efficiency.

Drawings

FIG. 1 is a schematic process flow diagram of the method of making an ultra short cycle high strength-high ductility nickel aluminum bronze alloy of the present invention;

FIG. 2 is a schematic diagram of an embodiment of a method of making an ultra-short cycle high strength-high ductility nickel aluminum bronze alloy in accordance with the present invention;

FIG. 3 is a scanning electron microscope image of the nickel-aluminum bronze alloy powder prepared by plasma electrode atomization in the method for preparing the ultrashort-cycle high-strength and high-ductility nickel-aluminum bronze alloy of the present invention;

FIG. 4 is a schematic diagram showing the grain size distribution of the nickel-aluminum bronze alloy powder prepared by plasma electrode atomization in the method for preparing an ultrashort-cycle high-strength and high-ductility nickel-aluminum bronze alloy according to the present invention;

FIG. 5 is a scanning electron micrograph of an ultra-short cycle high strength-high ductility nickel-aluminum bronze alloy prepared in example 1 of the present invention after polishing and etching;

FIG. 6 is the tensile test results of the ultrashort cycle high strength-high ductility nickel-aluminum bronze alloy prepared in example 1 of the present invention;

FIG. 7 is the tensile test results of the ultrashort cycle high strength-high ductility nickel-aluminum bronze alloy produced in example 2 of the present invention;

FIG. 8 is the tensile test results of the ultrashort cycle high strength-high ductility nickel aluminum bronze alloy produced in example 3 of the present invention;

FIG. 9 shows the relative density test results of ultrashort-cycle high-strength-high-ductility nickel-aluminum bronze alloys prepared in examples 1 to 3 of the present invention.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is described in further detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention. In addition, the technical features involved in the embodiments of the present invention described below may be combined with each other as long as they do not conflict with each other. The present invention will be described in further detail with reference to specific embodiments.

Example 1:

as shown in fig. 1-2, the preparation method of an ultrashort-period high-strength and high-ductility nickel-aluminum bronze alloy of the present invention comprises the following steps:

1) according to the weight ratio of Cu: al: ni: fe: molar ratio of Mn 81.1: 9.5: 4.2: 4.0: 1.2, selecting Cu powder, Al powder, Ni powder, Fe powder and Mn powder, wherein the average grain diameter of the powder is 45 mu m; uniformly mixing Cu powder, Al powder, Ni powder, Fe powder and Mn powder to obtain an initial ingredient;

2) obtaining a nickel-aluminum bronze bar with the diameter of 76mm by smelting, forging and heat treatment processes according to the ingredients, wherein the smelting process is carried out in a high-purity argon atmosphere;

3) the nickel-aluminum bronze bar is atomized by a plasma electrode atomization method, the atomization is carried out in high-purity argon, and the plasma electrode atomization process comprises the following steps: the rotating speed of the electrode rod is 20000r/min, the diameter of the electrode rod is 76mm, and spherical powder with the particle size of 45-105 μm is obtained;

4) and 3D printing the nickel-aluminum bronze alloy powder prepared by plasma electrode atomization by adopting a selective electron beam melting process to obtain the nickel-aluminum bronze alloy with high density, high strength and high ductility. The selective electron beam melting process comprises the following steps: the preheating temperature of the printing bottom plate is 600 ℃, and the 3D printing scanning speed is 50 m/s; the printing scanning speed is 1m/s, the single-layer scanning adopts a reciprocating mode, the interlayer rotation angle is 90 degrees, the filling space is 0.15mm, the scanning electron beam current is 5mA, and the diameter range of the plasma electrode atomized spherical powder is 45-105 μm.

FIG. 3 is a scanning electron microscope image of the nickel-aluminum bronze alloy powder prepared by the plasma rotary electrode atomization method in the present invention, and FIG. 4 is a schematic view of the grain size distribution of the nickel-aluminum bronze alloy powder prepared by the plasma electrode atomization method in the present invention, it can be seen that the powder sphericity is good, and the size distribution of the spherical powder is between 45-105 μm.

FIG. 5 is a scanning electron micrograph of the ultrashort-cycle high-strength and high-ductility nickel-aluminum bronze alloy prepared in example 1 after polishing and corrosion, which shows that the prepared nickel-aluminum bronze has uniform precipitated phase distribution and improved mechanical properties.

FIG. 6 shows the tensile test results of the ultrashort-cycle high-strength and high-ductility nickel-aluminum bronze alloy prepared in example 1 of the present invention, which shows that the tensile strength of the alloy reaches 996MPa, and the tensile strength is greatly improved compared with the data of the prior art.

Example 2:

4) and 3D printing the nickel-aluminum bronze alloy powder prepared by plasma electrode atomization by adopting a selective electron beam melting process to obtain the nickel-aluminum bronze alloy with high density, high strength and high ductility. The selective electron beam melting process comprises the following steps: the preheating temperature of the printing bottom plate is 600 ℃, and the 3D printing scanning speed is 50 m/s; the printing scanning speed is 1m/s, the single-layer scanning adopts a reciprocating mode, the interlayer rotation angle is 90 degrees, the filling space is 0.15mm, the scanning electron beam current is 5mA, and the diameter range of plasma electrode atomized spherical powder is 63-75 μm.

FIG. 7 shows the tensile test results of ultrashort-cycle high-strength and high-ductility nickel-aluminum bronze alloy prepared in example 2 of the present invention, wherein the tensile strength is 1035MPa, and the mechanical properties are greatly improved compared with those of conventional forged nickel-aluminum bronze. The extremely high yield strength is mainly caused by fine grain and uniform distribution of precipitated phase of the nickel-aluminum bronze prepared by the SEBM.

Example 3:

4) and 3D printing the nickel-aluminum bronze alloy powder prepared by plasma electrode atomization by adopting a selective electron beam melting process to obtain the nickel-aluminum bronze alloy with high density, high strength and high ductility. The selective electron beam melting process comprises the following steps: the preheating temperature of the printing bottom plate is 600 ℃, and the 3D printing scanning speed is 50 m/s; the printing scanning speed is 1m/s, the single-layer scanning adopts a reciprocating mode, the interlayer rotation angle is 90 degrees, the filling space is 0.15mm, the scanning electron beam current is 5mA, and the diameter range of plasma electrode atomized spherical powder is 75-105 μm.

FIG. 8 shows the tensile test results of the ultrashort-cycle high-strength and high-ductility nickel-aluminum bronze alloy prepared in example 3 of the present invention, wherein the tensile strength is 960MPa, and the mechanical properties are greatly improved compared with those of the conventional forged nickel-aluminum bronze.

FIG. 9 shows the results of testing the relative densities of the ultrashort-cycle high-strength and high-ductility nickel-aluminum bronze alloys obtained in examples 1, 2 and 3 of the present invention, which indicate that the relative densities of the nickel-aluminum bronze alloys are all above 99%, and that the nickel-aluminum bronze alloys have a dense microstructure and ensure excellent mechanical properties.

The invention can be realized by all the raw materials listed in the invention, and can be realized by the upper and lower limit values and interval values of all the raw materials, and can be realized by the upper and lower limit values and interval values of the process parameters (such as air pressure, temperature, time, vacuum degree and the like) listed in the invention, but the examples are not listed. It will be understood by those skilled in the art that the foregoing is only a preferred embodiment of the present invention, and is not intended to limit the invention, and that any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the scope of the present invention.

Claims

1. A preparation method of an ultrashort-period high-strength and high-ductility nickel-aluminum bronze alloy is characterized by comprising the following steps:

s1, according to Cu: al: ni: fe: mn molar ratio ═ (remainder): (8-12): (3.5-6.5): (2.5-5.5): (0.8-1.2), selecting Cu powder, Al powder, Ni powder, Fe powder and Mn powder, wherein the average grain diameter of the powder is 20-60 mu m; mixing Cu powder, Al powder, Ni powder, Fe powder and Mn powder to obtain a mixture, wherein the mixture does not contain a V element;

2. The method of making an ultrashort cycle high strength-high ductility nickel aluminum bronze alloy as claimed in claim 1, wherein:

in step S1, Cu: al: ni: fe: molar ratio of Mn 81.1: 9.5: 4.2: 4.0: 1.2.

3. the method of making an ultrashort cycle high strength-high ductility nickel aluminum bronze alloy as claimed in claim 1, wherein:

the melting process in step S2 is performed in a high-purity argon or nitrogen environment.

4. The method of making an ultrashort cycle high strength-high ductility nickel aluminum bronze alloy as claimed in claim 1, wherein:

the plasma electrode atomization process in step S3 is performed in a high-purity argon or nitrogen atmosphere.

5. The method of making an ultrashort cycle high strength-high ductility nickel aluminum bronze alloy as claimed in claim 1, wherein:

in step S3, the process conditions of the plasma electrode atomization process are as follows: the rotating speed of the electrode rod is 15000-30000r/min, and the diameter of the electrode rod is 50-100 mm.

6. The method of making an ultrashort cycle high strength-high ductility nickel aluminum bronze alloy as claimed in claim 1, wherein:

in step S4, the selective electron beam melting process conditions are:

7. The high-strength high-ductility nickel aluminum bronze alloy produced by the production method according to any one of claims 1 to 6, wherein:

the tensile strength of the nickel-aluminum bronze alloy is more than 900MPa, the uniform tensile elongation is more than 30%, and the relative compactness is more than 99%.