WO2020133680A1

WO2020133680A1 - Super short period nickel-aluminum-bronze alloy having high-strength and high-ductility, and preparation method therefor

Info

Publication number: WO2020133680A1
Application number: PCT/CN2019/076406
Authority: WO
Inventors: 卢文龙; 翟文正; 刘晓军
Original assignee: 华中科技大学
Priority date: 2018-12-25
Filing date: 2019-02-28
Publication date: 2020-07-02
Also published as: CN109628772B; CN109628772A

Abstract

A method for preparing a nickel-aluminum-bronze alloy, comprising: mixing Cu, Al, Ni, Fe and Mn powders according to a ratio, melting, forging and thermally treating the powders to obtain a bar, treating the bar by using plasma electrode atomization to obtain an alloy powder, using a selective electron beam melting process to perform 3D printing to obtain the alloy. The internal precipitate phase of the alloy is fine and evenly dispersed, the alloy having high density, and having high strength and high ductility.

Description

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

Technical field

The invention belongs to the field of nickel-aluminum bronze alloy, in particular to a preparation method of ultra-short period high strength-high ductility nickel aluminum bronze alloy, and the prepared ultra-short period high strength-high ductility nickel aluminum bronze alloy.

Background technique

For a long time, people have been devoted to exploring metals and alloys with high strength and high ductility to meet the demand. Traditional methods usually increase the strength of the material while reducing its ductility. In recent years, some innovative microstructure designs have included the introduction of high-density dislocations in the material organization structure (see literature 1. He, BBet al. High dislocation density-induced large ductility in deformed and partitioned steels. Science 357, 1029 (2017); Literature 2. Lu, L., Shen, Y., Chen, X., Qian, L. & Lu, K. Ultrahigh Strength and High Electrical Conductivity Copper. Science 304,422 (2004)), gradient nanocrystal structure (See Literature 3. Fang, TH, Li, WL, Tao, NR & Lu, K. Revealing Extraordinary Intrinsic Tensile Plasticity Nano-Grained Copper. Science 331, 1587-1590 (2011)) and bimodal grains (see literature 4. Wang, Y., Chen, M., Zhou, F. & Ma, E. High intensity of ductility in nanostructured metal. Nature. 419, 912 (2002)) can effectively overcome the above problems. However, these methods are more difficult to apply to the processing of mechanical parts with complex geometries. At the same time, because the above method requires multiple processing processes, it will cause processing repeatability problems caused by the increase of control variables, which is not conducive to the organization of manufacturing mechanical parts Stability of structure and performance. In recent years, the additive manufacturing method has given design and processing a high degree of freedom, making it an ideal solution to the above challenges (see literature 5.Zheng, X.et.al.Multiscale metallic metamaterials.NatureMater.15,1100(2016) ; Literature 6. Mchugh, KJet al. Fabrication of fillable microparticles and other complex 3D microstructures. Science 357, 1138 (2017)). Studies have shown that 316L stainless steel manufactured by laser powder melting (L-PBF) technology has both high yield strength and high ductility (see literature 7. Wang, YMet al. Additively manufactured hierarchical stainless steels with high strength and ductility. Nature, Mater. 17, 63-71 (2018); Literature 8. Sun, Z., Tan, X., Tor, SB & Chua, CK Simultaneously strengthened strength and ductility for 3D-printed stainless steel 316L by selective lasermelting.Npg Asia Mater.10 (2018); Literature 9.Liu,L.et.al.Dislocation,network,addition,manufactured,steel,breaks,strength-ductility,trade-off.Mater.Today,21,354-361 (2018)). However, the current 3D printing technology is often limited to the manufacture of easily weldable metal materials, such as stainless steel, titanium alloy, nickel alloy, etc. (see literature 10. Martin, JHetal. 3D printing of high-strength aluminum alloys. Nature 549, 365-369 (2017)), the use of 3D printing technology to manufacture a densely organized copper alloy with excellent performance is still a problem. For example, the partial melting phenomenon occurs during the process of manufacturing copper alloys using L-PBF technology, resulting in a relative density of less than 95% (see literature 11. .In High Value Manufacturing: Advanced Research in Virtual and Rapid Prototyping: Proceedings of the 6th International Conference on Advanced Research in Rapid Prototyping, Leiria, Portugal 285 (2013)). By adjusting the processing parameters of 3D printing, the relative density of the obtained Cu-Cr-Zr-Ti alloy reaches 97.9%, but because the internal grain size of the shaped part is mainly 30-250 μm columnar crystals, its tensile strength (UTS) ratio The traditional forged parts are 20-25% lower (see literature 12. Popovich, A.et.al.Microstructure and mechanical properties of additive manufacturing. alloy.Mater.Lett.179, 38-41 (2016)).

Selective electron beam melting (SEBM) is one of the key technologies of metal 3D printing manufacturing. It uses electron beams to selectively sinter metal powder under high vacuum to manufacture parts. Compared with selective laser melting (SLM), SEBM technology can provide a more uniform heating environment and higher energy density when 3D printing copper alloys, overcoming the problem of low energy absorption rate of copper alloys in SLM technology. At the same time, compared with the traditional method of manufacturing copper alloy parts (blanking-annealing-stamping-annealing-passivation, sometimes requiring multiple stamping and repeated annealing), SEBM technology can form nickel aluminum bronze alloy parts at once, and the density It is nearly completely dense, the relative density is greater than 99%, and its mechanical properties (including tensile strength and tensile elongation) are superior to similar products manufactured by the forging process, and have the advantages of short processing cycle and high efficiency.

Summary of the invention

In view of at least one of the above defects or improvement needs in the prior art, the present invention provides an ultra-short period high strength-high ductility nickel aluminum bronze alloy preparation method, the precipitated phase in the resulting alloy is fine and uniformly distributed , The alloy has high density, high strength and high ductility, and the process parameters are easy to control during the preparation process, and the processing cycle is short.

To achieve the above object, according to an aspect of the present invention, a method for preparing an ultra-short period high strength-high ductility nickel aluminum bronze alloy is provided, which is characterized by including the following steps:

S1, according to the molar ratio of Cu: Al: Ni: Fe: Mn = (remaining): (8-12): (3.5-6.5): (2.5-5.5): (0.8-1.2), select Cu powder, Al powder , Ni powder, Fe powder and Mn powder, the average particle size of the powder is 20-60μm; mix Cu powder, Al powder, Ni powder, Fe powder and Mn powder to obtain the ingredients;

S2. Nickel aluminum bronze rods with a diameter of 50-100mm are obtained by melting, forging and heat treatment processes according to the above ingredients;

S3. The plasma electrode atomization method is used to atomize the above nickel aluminum bronze rods;

S4. The nickel-aluminum-bronze alloy powder after the atomization treatment of the above-mentioned plasma electrode adopts a selective electron beam melting process to obtain a nickel-aluminum-bronze alloy with high density, high strength and high ductility through 3D printing.

Preferably, in step S1, the molar ratio of Cu:Al:Ni:Fe:Mn=81.1:9.5:4.2:4.0:1.2.

Preferably, the smelting 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 environment.

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

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

The preheating temperature of the 3D printing bottom plate is 400-800℃, the scanning speed of the 3D printing is 20-50m/s; the printing scanning speed is 0.5-1m/s, the single layer scanning adopts the reciprocating method, the rotation angle between the layers is 0-90°, Filling distance 0.15mm, scanning electron beam current 2-5mA, plasma electrode atomizing spherical powder diameter range 45-105μm.

In order to achieve the above object, according to one aspect of the present invention, there is also provided a high-strength-high-ductility nickel-aluminum-bronze alloy obtained by using the preparation method described above. The tensile strength of the nickel-aluminum-bronze alloy is above 900 MPa, preferably It is above 960Mpa, the uniform stretch elongation is above 30%, and the relative density is above 99%.

The above-mentioned preferred technical features can be combined with each other as long as there is no conflict with each other.

Generally speaking, the above technical solutions conceived by the present invention have the following beneficial effects compared with the prior art:

1. The preparation method of the ultra-short period high strength-high ductility nickel-aluminum-bronze alloy of the present invention, the precipitation phase of the prepared nickel-aluminum-bronze alloy is uniformly dispersed, which overcomes the unevenness of the dispersion of the precipitated phase caused by the traditional preparation process and leads to mechanical properties The lack of decline;

2. The preparation method of the ultra-short period high strength-high ductility nickel aluminum bronze alloy of the present invention, the prepared nickel aluminum bronze alloy has high density and excellent mechanical properties.

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

4. The preparation method of the ultra-short period high strength-high ductility nickel aluminum bronze alloy of the present invention adopts the selective electron beam melting process (SEBM), which uses electron beams to selectively sinter metal powder under high vacuum to manufacture Parts. Compared with selective laser melting (SLM), SEBM technology can provide a more uniform heating environment and higher energy density when 3D printing copper alloys, overcoming the problem of low energy absorption rate of copper alloys in SLM technology. At the same time, compared with the traditional method of manufacturing copper alloy parts (blanking-annealing-stamping-annealing-passivation, sometimes requiring multiple stamping and repeated annealing), SEBM technology can form nickel aluminum bronze alloy parts at once, and the density It is nearly completely dense, the relative density is greater than 99%, and its mechanical properties (including tensile strength and tensile elongation) are superior to similar products manufactured by the forging process, and have the advantages of short processing cycle and high efficiency.

BRIEF DESCRIPTION

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

2 is a schematic diagram of an embodiment of the preparation method of the ultra-short period high strength-high ductility nickel aluminum bronze alloy of the present invention;

3 is a scanning electron micrograph of nickel-aluminum-bronze alloy powder prepared by plasma electrode atomization in the preparation method of the ultra-short period high-strength-high-ductility nickel-aluminum-bronze alloy of the present invention;

4 is a schematic diagram of the grain size distribution of the nickel-aluminum-bronze alloy powder prepared by the plasma electrode atomization method in the preparation method of the ultra-short period high-strength-high-ductility nickel-aluminum-bronze alloy of the present invention;

5 is a scanning electron microscope photograph of the ultra-short period high strength-high ductility nickel aluminum bronze alloy polished and corroded in Example 1 of the present invention;

6 is a tensile test result of an ultra-short period high strength-high ductility nickel aluminum bronze alloy prepared in Example 1 of the present invention;

7 is a tensile test result of the ultra-short period high strength-high ductility nickel aluminum bronze alloy prepared in Example 2 of the present invention;

8 is a tensile test result of an ultra-short period high strength-high ductility nickel aluminum bronze alloy prepared in Example 3 of the present invention;

FIG. 9 is a result of the relative density test of the ultra-short period high strength-high ductility nickel aluminum bronze alloy prepared in Examples 1-3 of the present invention.

detailed description

In order to make the objectives, technical solutions and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention, and are not intended to limit the present invention. In addition, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as there is no conflict with each other. The present invention will be further described in detail below in conjunction with specific embodiments.

Example 1:

As shown in FIG. 1-2, a method for preparing an ultra-short period high strength-high ductility nickel aluminum bronze alloy of the present invention includes the following steps:

1) According to the molar ratio of Cu:Al:Ni:Fe:Mn=81.1:9.5:4.2:4.0:1.2, select Cu powder, Al powder, Ni powder, Fe powder and Mn powder, the average particle size of the powder is 45μm ; Mix Cu powder, Al powder, Ni powder, Fe powder and Mn powder uniformly to obtain the initial ingredients;

2) According to the above ingredients, the nickel aluminum bronze rod with a diameter of 76mm is obtained through smelting, forging and heat treatment processes, and the smelting process is carried out in a high-purity argon atmosphere;

3) The plasma electrode atomization method is used to atomize the above nickel aluminum bronze rod material, and the atomization is performed in high-purity argon gas. The plasma electrode atomization process is: electrode rod speed is 20000r/min, electrode rod diameter is 76mm , To obtain spherical powder with a particle size of 45-105μm;

4) For the nickel-aluminum-bronze alloy powder prepared by atomizing the plasma electrode, a selective electron beam melting process is used to obtain a nickel-aluminum-bronze alloy with high density, high strength and high ductility through 3D printing. Among them, the selective electron beam melting process is: the preheating temperature of the printing substrate is 600 ℃, the scanning speed of 3D printing is 50m/s; the printing scanning speed is 1m/s, the single-layer scanning adopts a reciprocating method, and the rotation angle between the layers is 90°. Filling pitch 0.15mm, scanning electron beam current 5mA, plasma electrode atomized spherical powder diameter range 45-105μm.

3 is a scanning electron micrograph of 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 sphericity of the powder is better, and the size distribution of the spherical powder is between 45-105 μm.

5 is a scanning electron micrograph of the ultra-short period high strength-high ductility nickel aluminum bronze alloy prepared in Example 1 of the present invention after being polished and corroded. It can be seen that the precipitation phase of the prepared nickel aluminum bronze is uniformly distributed, which can improve its Mechanical properties.

FIG. 6 is the tensile test results of the ultra-short period high strength-high ductility nickel aluminum bronze alloy prepared in Example 1 of the present invention. It can be seen that the tensile strength reaches 996 MPa. Compared with the existing literature data, the tensile strength is obtained Greatly improved.

Example 2:

4) For the nickel-aluminum-bronze alloy powder prepared by atomizing the plasma electrode, a selective electron beam melting process is used to obtain a nickel-aluminum-bronze alloy with high density, high strength and high ductility through 3D printing. Among them, the selective electron beam melting process is: the preheating temperature of the printing substrate is 600 ℃, the scanning speed of 3D printing is 50m/s; the printing scanning speed is 1m/s, the single-layer scanning adopts a reciprocating method, and the rotation angle between the layers is 90°. Filling pitch 0.15mm, scanning electron beam current 5mA, plasma electrode atomized spherical powder diameter range 63-75μm.

FIG. 7 is the tensile test result of the ultra-short period high strength-high ductility nickel aluminum bronze alloy prepared in Example 2 of the present invention. Its tensile strength reaches 1035MPa, and its mechanical properties are larger than that of traditional forged nickel aluminum bronze Improvement. The extremely high yield strength is mainly due to the fine grains of nickel aluminum bronze prepared by SEBM and the uniform distribution of precipitated phases.

Example 3:

4) For the nickel-aluminum-bronze alloy powder prepared by atomizing the plasma electrode, a selective electron beam melting process is used to obtain a nickel-aluminum-bronze alloy with high density, high strength and high ductility through 3D printing. Among them, the selective electron beam melting process is: the preheating temperature of the printing substrate is 600 ℃, the scanning speed of 3D printing is 50m/s; the printing scanning speed is 1m/s, the single-layer scanning adopts a reciprocating method, and the rotation angle between the layers is 90°. Filling pitch 0.15mm, scanning electron beam current 5mA, plasma electrode atomizing spherical powder diameter range 75-105μm.

FIG. 8 is the tensile test result of the ultra-short period high strength-high ductility nickel aluminum bronze alloy prepared in Example 3 of the present invention. Its tensile strength reaches 960MPa, and its mechanical properties are larger than those of traditional forged nickel aluminum bronze Improvement.

9 is a test of the relative density results of ultra-short period high strength-high ductility nickel aluminum bronze alloys prepared in Examples 1, 2, and 3 of the present invention, showing that the relative density of the nickel aluminum bronze alloys are all above 99%, It shows that the nickel-aluminum-bronze alloy has a dense microstructure to ensure its excellent mechanical properties.

Each raw material listed in the present invention can realize the present invention, and the upper and lower limit values and interval values of each raw material can realize the present invention, and the upper and lower limits of the process parameters (such as air pressure, temperature, time, vacuum degree, etc.) of the present invention Both the value and the interval value can implement the present invention, and embodiments are not listed here one by one. It is easily understood by those skilled in the art that the above is only the preferred embodiment of the present invention and is not intended to limit the present invention. Any modification, equivalent replacement and improvement made within the spirit and principle of the present invention, All should be included in the protection scope of the present invention.

Claims

An ultra-short period high strength-high ductility nickel aluminum bronze alloy preparation method, characterized in that it includes the following steps:

S1, according to the molar ratio of Cu: Al: Ni: Fe: Mn = (remaining): (8-12): (3.5-6.5): (2.5-5.5): (0.8-1.2), select Cu powder, Al powder , Ni powder, Fe powder and Mn powder, the average particle size of the powder is 20-60μm; mix Cu powder, Al powder, Ni powder, Fe powder and Mn powder to obtain the ingredients;

S2. Nickel aluminum bronze rods with a diameter of 50-100mm are obtained by melting, forging and heat treatment processes according to the above ingredients;

S3. The plasma electrode atomization method is used to atomize the above nickel aluminum bronze rods;

S4. The nickel-aluminum-bronze alloy powder after the atomization treatment of the above-mentioned plasma electrode adopts a selective electron beam melting process to obtain a nickel-aluminum-bronze alloy with high density, high strength and high ductility through 3D printing.
The preparation method of the ultra-short period high strength-high ductility nickel aluminum bronze alloy according to claim 1, characterized in that:

In step S1, the molar ratio of Cu:Al:Ni:Fe:Mn=81.1:9.5:4.2:4.0:1.2.
The preparation method of the ultra-short period high strength-high ductility nickel aluminum bronze alloy according to claim 1, characterized in that:

The smelting process in step S2 is performed in a high-purity argon or nitrogen environment.
The preparation method of the ultra-short period high strength-high ductility nickel aluminum bronze alloy according to claim 1, characterized in that:

The plasma electrode atomization process in step S3 is performed in a high-purity argon or nitrogen environment.
The preparation method of the ultra-short period high strength-high ductility nickel aluminum bronze alloy according to claim 1, characterized in that:

In step S3, the process conditions of the plasma electrode atomization treatment are: the rotation speed of the electrode rod is 15000-30000r/min, and the diameter of the electrode rod is 50-100mm.
The preparation method of the ultra-short period high strength-high ductility nickel aluminum bronze alloy according to claim 1, characterized in that:

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

The preheating temperature of the 3D printing bottom plate is 400-800℃, the scanning speed of the 3D printing is 20-50m/s; the printing scanning speed is 0.5-1m/s, the single layer scanning adopts the reciprocating method, the rotation angle between the layers is 0-90°, Filling distance 0.15mm, scanning electron beam current 2-5mA, plasma electrode atomizing spherical powder diameter range 45-105μm.
The high strength-high ductility nickel-aluminum-bronze alloy produced by the preparation method according to any one of claims 1-6 is characterized in that:

The tensile strength of nickel-aluminum-bronze alloy is above 900MPa, the uniform tensile elongation is above 30%, and the relative density is above 99%.