阅读说明：本技术 一种超塑韧性钨合金材料及其制备方法 (Superplastic tough tungsten alloy material and preparation method thereof ) 是由 舒大禹 陈强 吴洋 詹红 夏祥生 赵祖德 赵强 屈俊岑 宁海青 于 2019-11-27 设计创作，主要内容包括：一种超塑韧性钨合金材料的制备方法,原料为镍Ni质量分数为30%～55%、铝Al质量分数为12%～25%、余量为钨W,使其形成单相固溶体钨合金,包括多元合金化设计、高能球磨、悬浮熔炼、反向温度场锻造。本发明的钨合金材料塑韧性好,满足了一些特种功能构件对钨合金材料的高塑性、高致密、高冲击韧性、细晶均匀化要求,比传统工艺制备的钨合金材料伸长率提高约1倍、冲击吸收能量提高1倍以上。(A preparation method of a superplastic tough tungsten alloy material comprises the following steps of forming a single-phase solid solution tungsten alloy by using 30-55% of nickel (Ni) by mass, 12-25% of aluminum (Al) by mass and the balance of tungsten (W) by mass, and performing multi-element alloying design, high-energy ball milling, suspension smelting and reverse temperature field forging. The tungsten alloy material has good plasticity and toughness, meets the requirements of high plasticity, high compactness, high impact toughness and fine grain homogenization of some special functional components on the tungsten alloy material, and improves the elongation rate by about 1 time and the impact absorption energy by more than 1 time compared with the tungsten alloy material prepared by the traditional process.)

1. A preparation method of a superplastic toughness tungsten alloy material comprises the following steps of forming a single-phase solid solution tungsten alloy by using 30-55% of Ni by mass, 12-25% of Al by mass and the balance of W by mass, and performing multi-element alloying design, high-energy ball milling, suspension smelting and reverse temperature field forging.

2. The method for preparing the superplastic tough tungsten alloy material of claim 1, wherein the raw material is added with lanthanum cerium composite rare earth (La-40% Ce) with the mass fraction of (0.5-1.5%).

3. The method for preparing the superplastic tough tungsten alloy material according to claim 1 or 2, comprising the steps of:

step 1: determining the mass fractions of nickel (Ni) and aluminum (Al) in the single-phase tungsten alloy according to a binary alloy phase diagram and a ternary alloy phase diagram to form a solid solution alloy, wherein the mass fraction of Ni is 30-55%, the mass fraction of Al is 12-25%, the mass fraction of lanthanum-cerium composite rare earth (La-40% Ce) is 0.5-1.5%, and the balance is W;

step 2: selecting tungsten powder, nickel powder, aluminum powder and lanthanum-cerium composite rare earth, wherein the tungsten powder is the best plasma spheroidized powder, the purity is 99.95%, the particle size of the powder is selected from (4-8) mu m and (10-15) mu m, and the tungsten powder, the nickel powder, the aluminum powder and the lanthanum-cerium composite rare earth are mixed according to a certain proportion for use; the nickel powder is electrolytic nickel powder, the purity is 99.9%, and the particle size of the powder is 5-15 mu m; the Al powder is gas atomized powder, the purity is 99.95%, and the particle size of the powder is 5-20 mu m; the purity of the lanthanum-cerium composite rare earth is 99.5 percent, and the particle size of the powder is 10-30 mu m;

and step 3: and (2) weighing the powder in the step (2) by adopting a high-energy ball milling method, mixing the four kinds of powder together, and uniformly mixing the powder by a ball milling method, wherein the ball-material ratio is 2: 1-5: 1, ball milling at a rotating speed of 600-1200 r/min for 2-10 h, and taking liquid nitrogen, ethanol and the like as protective media;

and 4, step 4: pressing the mixed powder obtained in the step (3) into a bar blank or a square blank with a certain density by adopting a die pressing method, wherein the relative density is 55-70%;

and 5: sintering the blank obtained in the step 4 by adopting a hydrogen protective atmosphere sintering process, wherein the density is 85-92% by adopting hydrogen flow (400-800) ml/min and sintering process (650-850) DEG C (2-5) h;

step 6: adopting an electromagnetic suspension smelting method to carry out suspension smelting on the sintered blank obtained in the step 5, wherein the limit pressure is 6.67 multiplied by 10^-3Pa, a pressure rise rate (0.21-0.63) Pa/h, medium-frequency power (300-800) kW, frequency (20-100) Hz, smelting time (8-20) min/kg and smelting temperature (2100-3200) DEG C;

and 7: carrying out slab stripping on the bar blank obtained in the step 6, then carrying out heating treatment at the heating temperature of 600-950 ℃ for 0.5-4 h, and carrying out reverse temperature field forging homogenization deformation treatment on a mechanical press;

and 8: carrying out recrystallization heat treatment on the deformed blank obtained in the step 7, wherein the heat treatment process is (800-1200) DEG C x (1-4) h, and the vacuum degree is less than or equal to 5 x 10^-3Pa；

And step 9: and (4) detecting the metallographic structure, the mechanical property and the like of the tungsten alloy material obtained in the step (8).

4. The method for preparing superplastic tough tungsten alloy material according to any one of claims 1 to 3, wherein the mass fraction of the ternary alloy nickel and aluminum in step 1 is 40 to 48 percent of the mass fraction of Ni and 15 to 20 percent of the mass fraction of Al.

5. The method for preparing the superplastic tough tungsten alloy material according to any one of claims 1 to 4, wherein in the step 6, suspension smelting is performed for 2 to 3 times, wherein the 1 st smelting has a pressure rise rate (0.4 to 0.6) Pa/h, medium-frequency power (500 to 800) kW, frequency (50 to 100) Hz, smelting time (10 to 15) min/kg, and smelting temperature (2300 to 2550) DEG C; the 2 nd smelting pressure rise rate (0.3-0.4) Pa/h, the medium-frequency power (300-500) kW, the frequency (50-80) Hz, the smelting time (8-15) min/kg and the smelting temperature (2500-2750) DEG C; the 3 rd smelting pressure rise rate (0.25-0.3) Pa/h, the medium-frequency power (300-500) kW, the frequency (30-50) Hz, the smelting time (8-10) min/kg and the smelting temperature (2700-2900) DEG C.

6. The method for preparing the superplastic tough tungsten alloy material according to any one of claims 1 to 5, wherein in the step 7, the reverse temperature field forging is performed for not less than 3 times, the blank is heated at 650 to 900 ℃ for 1 to 3 hours; heating the mould at 750-1100 ℃ for 1-2 h; the deformation of different parts is 35-70%.

7. The method for preparing the superplastic tough tungsten alloy material according to any one of claims 1 to 6, wherein in the step 8, the recrystallization heat treatment is carried out at the temperature of 1000 to 1150 ℃ for 1 to 2 hours.

Technical Field

The invention relates to the technical field of special smelting and large plastic deformation, in particular to a preparation method of a superplastic toughness tungsten alloy material.

Background

According to the theory of cumulative jet penetration, penetration capability is closely related to material density, jet head speed, jet length and the like, the increase of the jet length requires the increase of the velocity gradient and effective jet quality of the jet, and the great increase of the velocity gradient of the jet requires the material to have high sound velocity, good plasticity and high density. Tungsten, molybdenum, uranium and the like are used as energy gathering penetration materials, so that although the jet density and the unit volume mass are improved, the difficulty of material preparation and subsequent processing is greatly increased.

The blockade of the military and warfare technologies in the United states, Germany, and the like, particularly relating to key component materials and core manufacturing technologies, has little valuable information to be looked up. According to analysis of a large amount of literature data, the existing manufacturing method of the tungsten alloy material comprises the following steps: the powder metallurgy method has the advantages that in the aspect of manufacturing, for the variable cross-section appearance with thin walls, large height-diameter ratio and the like, the density distribution is that the density of the top and the mouth is large, the density of the middle part is small, the density distribution of different parts is uneven, and the density is about 97%; in the aspect of materials, the powder mixed by a plurality of metal materials is adopted, and the powder has different physical properties such as specific gravity, granularity, hardness and the like, so that the layering phenomenon is easy to generate in the conventional die pressing process, the density distribution is also uneven, and the defects cause the comprehensive use performance of the material to be reduced. The other is a vapor deposition method, in which a tungsten alloy material layer is deposited on the surface of a core mold by a physical or chemical method, which has the technical problems of low density (about 98%), high impurity content (about 0.8%) and the like, and the material has high brittleness and poor ductility and toughness, and cannot exert the specific properties of the material.

In order to further improve the comprehensive use performance of the tungsten alloy material, the tungsten alloy material is required to have better isotropy, fine and uniform crystal grains and good ductility from the correlation among the uniformity of the material structure, the consistency of the performance and the penetration power. The prior art mainly adopts the traditional powder metallurgy, vapor deposition and rolling, and the process has the following defects: firstly, the compactness is not high, the impurity content is high, and the ductility of the material is not good; secondly, tungsten alloy elements are not uniformly distributed, and the tissue symmetry is poor; and thirdly, brittle compounds are easily formed at the interfaces of the tungsten particles, the plasticity and toughness of the material are poor, and especially under the action of high strain rate, weak bonding layers among the tungsten particles become crack sources.

Disclosure of Invention

The invention provides a superplastic tough tungsten alloy material, which meets the requirements of high plasticity, high compactness, high impact toughness and fine grain homogenization of certain special functional components on the tungsten alloy material.

In order to achieve the purpose, the technical scheme adopted by the invention is as follows:

a preparation method of a superplastic tough tungsten alloy material comprises the following steps of forming a single-phase solid solution tungsten alloy by using 30-55% of nickel (Ni) by mass, 12-25% of aluminum (Al) by mass and the balance of tungsten (W) by mass, and performing multi-element alloying design, high-energy ball milling, suspension smelting and reverse temperature field forging.

In order to improve the purity of the tungsten alloy, lanthanum-cerium composite rare earth (La-40% Ce) with the mass fraction of (0.5-1.5%) is added.

The superplastic tough tungsten alloy material and the preparation method thereof are characterized by comprising the following steps:

step 1: determining the mass fractions of nickel (Ni) and aluminum (Al) in the single-phase tungsten alloy according to a binary alloy phase diagram and a ternary alloy phase diagram to form a solid solution alloy, wherein the mass fraction of Ni is 30-55%, the mass fraction of Al is 12-25%, the mass fraction of lanthanum-cerium composite rare earth (La-40% Ce) is 0.5-1.5%, and the balance is W;

step 2: selecting tungsten powder, nickel powder, aluminum powder and lanthanum-cerium composite rare earth, wherein the tungsten powder is the best plasma spheroidized powder, the purity is 99.95%, the particle size of the powder is selected from (4-8) mu m and (10-15) mu m, and the tungsten powder, the nickel powder, the aluminum powder and the lanthanum-cerium composite rare earth are mixed according to a certain proportion for use; the nickel powder is electrolytic nickel powder, the purity is 99.9%, and the particle size of the powder is 5-15 mu m; the Al powder is gas atomized powder, the purity is 99.95%, and the particle size of the powder is 5-20 mu m; the purity of the lanthanum-cerium composite rare earth is 99.5 percent, and the particle size of the powder is 10-30 mu m.

And step 3: and (2) weighing the powder in the step (2) by adopting a high-energy ball milling method, mixing the four kinds of powder together, and uniformly mixing the powder by a ball milling method, wherein the ball-material ratio is 2: 1-5: 1, ball milling at a rotating speed of 600-1200 r/min for 2-10 h, and taking liquid nitrogen, ethanol and the like as protective media;

and 4, step 4: pressing the mixed powder obtained in the step (3) into a bar blank or a square blank with a certain density by adopting a die pressing method, wherein the relative density is 55-70%;

and 5: sintering the blank obtained in the step 4 by adopting a hydrogen protective atmosphere sintering process, wherein the density is 85-92% by adopting hydrogen flow (400-800) ml/min and sintering process (650-850) DEG C (2-5) h;

step 6: adopting an electromagnetic suspension smelting method to carry out suspension smelting on the sintered blank obtained in the step 5, wherein the limit pressure is 6.67 multiplied by 10^-3Pa, a pressure rise rate (0.21-0.63) Pa/h, medium-frequency power (300-800) kW, frequency (20-100) Hz, smelting time (8-20) min/kg and smelting temperature (2100-3200) DEG C;

and 7: carrying out slab stripping on the bar blank obtained in the step 6, then carrying out heating treatment at the heating temperature of 600-950 ℃ for 0.5-4 h, and carrying out reverse temperature field forging homogenization deformation treatment on a mechanical press;

and 8: carrying out recrystallization heat treatment on the deformed blank obtained in the step 7, wherein the heat treatment process is (800-1200) DEG C x (1-4) h, and the vacuum degree is less than or equal to 5 x 10^-3Pa；

And step 9: and (4) detecting the metallographic structure, the mechanical property and the like of the tungsten alloy material obtained in the step (8).

Further, in the step 1, the mass fraction of the ternary alloy nickel and the mass fraction of the ternary alloy aluminum are 40-48% of the mass fraction of Ni and 15-20% of the mass fraction of Al.

Further, in the step 6, suspension smelting needs to be carried out for 2-3 times, the 1 st smelting pressure rise rate (0.4-0.6) Pa/h, the medium-frequency power (500-800) kW, the frequency (50-100) Hz, the smelting time (10-15) min/kg and the smelting temperature (2300-2550) DEG C; the 2 nd smelting pressure rise rate (0.3-0.4) Pa/h, the medium-frequency power (300-500) kW, the frequency (50-80) Hz, the smelting time (8-15) min/kg and the smelting temperature (2500-2750) DEG C; the 3 rd smelting pressure rise rate (0.25-0.3) Pa/h, the medium-frequency power (300-500) kW, the frequency (30-50) Hz, the smelting time (8-10) min/kg and the smelting temperature (2700-2900) DEG C.

Further, in the step 7, the forging times of the reverse temperature field are not less than 3, the blank heating temperature is 650-900 ℃, and the heat preservation time is 1-3 h; heating the mould at 750-1100 ℃ for 1-2 h; the deformation of different parts is 35-70%.

Further, in the step 8, recrystallization heat treatment is carried out, the heat preservation temperature is 1000-1150 ℃, and the heat preservation time is 1-2 hours.

Advantageous effects

1. The invention adopts a suspension smelting and reverse temperature field forging deformation method, improves the problem of uneven tungsten components, obtains uniform deformation texture and prepares the high-purity tungsten alloy material.

2. The tungsten alloy material has uniform and fine structure, the average grain size is less than or equal to 12 mu m, the content of elements such as oxygen, hydrogen, sulfur and the like in the material is less than or equal to 0.013 wt%, and the density deviation is less than or equal to 0.1%, so that the tungsten alloy material with high plasticity and high toughness is prepared.

3. According to the tungsten alloy material, W, Ni and Al form a complete solid solution, elements are uniformly distributed, and the tungsten alloy material has the advantages of tensile strength (960-1045) MPa, yield strength (670-720) MPa, elongation after fracture (35-46)%, reduction of area (42-53)%, and impact absorption energy (52-73) J under the room temperature condition.

4. The tungsten alloy material has good plasticity and toughness, and the elongation of the tungsten alloy material is improved by about 1 time and the impact absorption energy is improved by more than 1 time (the elongation of the general tungsten alloy material is 20-25 percent, and the impact absorption energy is not more than 20J) compared with the tungsten alloy material prepared by the traditional process.

The specific implementation mode is as follows:

the present invention is further illustrated by the following examples, but the present invention is not limited to these examples.