阅读说明：本技术 一种多元掺杂高比重钨铜镍合金的制备方法及制备的高比重钨铜镍合金 (Preparation method of multi-element doped high-specific gravity tungsten copper nickel alloy and prepared high-specific gravity tungsten copper nickel alloy ) 是由 刘东光 张力 罗来马 吴玉程 阮崇飞 朱晓勇 于 2020-08-24 设计创作，主要内容包括：本发明公开一种多元掺杂高比重钨铜镍合金的制备方法,涉及高比重合金材料领域,基于现有的钨基高比重合金致密度较低、力学性能差的问题而提出的。本发明包括以下步骤：(1)称取原料纯钨粉、铜粉、镍粉、氧化钇粉、氢化锆粉和钛粉；(2)原料球磨18-24h；(3)高温煅烧。本发明还提供上述多元掺杂高比重钨铜镍合金的制备方法制得的高比重钨铜镍合金。本发明通过在合金中掺杂微量的氧化钇和锆、钛合金元素,产生固溶强化,促进烧结致密化,使得烧结后的钨铜镍合金完全致密,密度最高达到16.5g/cm<Sup>3</Sup>,甚至超过了16.31g/cm<Sup>3</Sup>的理论密度；同时显微硬度最高达到695.93HV远超一般的高比重钨铜镍合金。(The invention discloses a preparation method of a multi-element doped high-specific gravity tungsten copper nickel alloy, relates to the field of high-specific gravity alloy materials, and is provided based on the problems of lower density and poor mechanical property of the existing tungsten-based high-specific gravity alloy. The invention comprises the following steps: (1) weighing raw materials of pure tungsten powder, copper powder, nickel powder, yttrium oxide powder, zirconium hydride powder and titanium powder; (2) ball milling raw materials for 18-24 h; (3) and (4) high-temperature calcination. The invention also provides the high-specific gravity tungsten-copper-nickel alloy prepared by the preparation method of the multi-element doped high-specific gravity tungsten-copper-nickel alloy. According to the invention, trace yttrium oxide, zirconium and titanium alloy elements are doped in the alloy to generate solid solution strengthening and promote sintering densification, so that the sintered tungsten-copper-nickel alloy is completely densified, and the density can reach 16.5g/cm at most 3 Even more than 16.31g/cm 3 The theoretical density of (a); meanwhile, the microhardness of the alloy can reach 695.93HV to exceed that of common high-specific-gravity tungsten-copper-nickel alloy.)

1. The preparation method of the multi-element doped high-specific gravity tungsten copper nickel alloy is characterized by comprising the following steps of:

(1) respectively weighing 88.5-90.5% of pure tungsten powder, 5% of copper powder, 3% of nickel powder, 0.5% of yttrium oxide powder, 0.5-1.5% of zirconium hydride powder and 0.5-1.5% of titanium powder according to weight percentage;

(2) stirring and ball-milling the raw material powder weighed in the step (1), and stirring and ball-milling for 18-24 hours under the argon atmosphere condition according to the ball-to-material ratio of 5:1 to prepare mixed powder;

(3) and (3) high-temperature sintering: putting the mixed powder subjected to ball milling in the step (2) into a graphite mould, putting the mould into a discharge plasma sintering furnace, introducing hydrogen into the furnace chamber, vacuumizing the furnace chamber at room temperature, heating to 600 ℃ at a heating rate of 100 ℃/min for 6min, preserving heat for 5min, and pressurizing to 20Mpa during heat preservation; heating to 1050 deg.C at a heating rate of 100 deg.C/min for 4.5min, pressurizing to 70MPa, and maintaining for 5-10 min; and then the temperature is reduced to room temperature at the cooling rate of 100 ℃/min, and the multielement doped high specific gravity tungsten-copper-nickel alloy is obtained.

2. The preparation method of the multi-element doped high specific gravity tungsten copper nickel alloy as claimed in claim 1, wherein the preparation method comprises the following steps: the purity of the pure tungsten powder is 99.8%, and the granularity is 1.8-2.2 μm.

3. The preparation method of the multi-element doped high specific gravity tungsten copper nickel alloy as claimed in claim 1, wherein the preparation method comprises the following steps: the purity of the copper powder is 99.9%, and the particle size is 35 mu m.

4. The preparation method of the multi-element doped high specific gravity tungsten copper nickel alloy as claimed in claim 3, wherein the preparation method comprises the following steps: the purity of the nickel powder is 99.9%, and the particle size is 30 mu m.

5. The preparation method of the multi-element doped high specific gravity tungsten copper nickel alloy as claimed in claim 1, wherein the preparation method comprises the following steps: the purity of the yttrium oxide powder is 99.8%, and the particle size is 30 mu m.

6. The preparation method of the multi-element doped high specific gravity tungsten copper nickel alloy as claimed in claim 1, wherein the preparation method comprises the following steps: the purity of the zirconium hydride powder was 99.9%, and the particle size was 1 μm.

7. The preparation method of the multi-element doped high specific gravity tungsten copper nickel alloy as claimed in claim 1, wherein the preparation method comprises the following steps: the purity of the titanium powder is 99.7%, and the granularity is 32.5 mu m.

8. The preparation method of the multi-element doped high specific gravity tungsten copper nickel alloy as claimed in claim 1, wherein the preparation method comprises the following steps: and (3) in the step (2), the rotating speed of the ball mill is 500 r/min.

9. The preparation method of the multi-element doped high specific gravity tungsten copper nickel alloy as claimed in claim 1, wherein the preparation method comprises the following steps: the flow rate of hydrogen in the step (3) is 0.15L/min.

10. The multi-element doped high specific gravity tungsten copper nickel alloy prepared by the preparation method of the multi-element doped high specific gravity tungsten copper nickel alloy as claimed in any one of claims 1 to 9.

Technical Field

The invention relates to the field of high-specific gravity alloy materials, in particular to a preparation method of a multi-element doped high-specific gravity tungsten copper nickel alloy and the prepared high-specific gravity tungsten copper nickel alloy.

Background

The high specific gravity tungsten alloy is also called high density tungsten alloy. The alloy is formed by taking tungsten as a matrix (the content is more than 85 percent), adding elements such as copper, nickel, iron and the like as a main binding phase, and adding a small amount of strengthening elements (such as molybdenum, titanium and the like). Tungsten particles whose microstructure is simple substance are bonded by a liquid phase formed by melting of alloy elements. The tungsten particles are a hard and brittle phase, the binding phase is a tough phase, and the high specific gravity tungsten alloy has such components and structure as to determine the excellent comprehensive mechanical properties. Compared with other high-specific gravity materials, the high-specific gravity tungsten alloy has the excellent performances of high strength, high density, small thermal expansion coefficient, good corrosion resistance and oxidation resistance, good electric conduction and heat conduction performance, good ductility and the like. The high-strength high.

However, because tungsten and copper are not mutually soluble, it is difficult to obtain a fully dense and uniform-structure high-specific-gravity tungsten-copper alloy by conventional liquid phase sintering, and thus it is difficult to fully exert the performance advantages of the material. Particularly, the hardness of the material is difficult to improve due to lower sintering compactness and the agglomeration of copper phases. The traditional preparation of tungsten-based high specific gravity alloy is to mix all element powders and adopt liquid phase sintering to reach nearly full density, and the prepared tungsten alloy has large grains (about 30-40 μm) due to large powder particle size (2-4 μm), high sintering temperature and long sintering time. For example, a Mo-W-Ni-Cu alloy sintered in liquid phase can obtain the maximum tensile strength of 1100MPa, but has the highest hardness of 390HV only when the total content of copper and nickel does not exceed 6 percent. The high specific gravity ferrotungsten alloys commonly used in armor-piercing materials require higher hardness and strength, but only when the total amount of ferronickel is 2%, the highest hardness is 310 HV. With the technological progress and the technical development, the performance of the tungsten-copper alloy material with high specific gravity has higher requirements.

The application number is CN201510454364.1 discloses a preparation method of tungsten-copper-nickel alloy powder, carbonyl nickel powder is added into atomized copper powder and crystalline tungsten powder, the atomized copper powder and the crystalline tungsten powder are placed in a steel belt reduction furnace, high-temperature diffusion treatment is carried out in protective gas or reducing atmosphere, the atomized copper powder and the crystalline tungsten powder are enabled to realize alloy connection through diffusion of the carbonyl nickel powder in the atomized copper powder and the crystalline tungsten powder, and the tungsten-copper-nickel alloy powder is obtained through crushing and screening of a crusher. However, it is not easy to improve the material properties of the high specific gravity tungsten copper alloy while maintaining its high density. The mechanical properties of the material can be improved without reducing the higher density of the material only by doping a small amount of various trace elements and improving various processes such as powder making, sintering and the like.

The patent with the application number of CN201811105619.3 discloses a preparation method of a tungsten-based high-specific gravity alloy material, which comprises the following steps of firstly preparing a tungsten-based high-specific gravity alloy material by adopting an intermittent stirring ball mill, wherein the ratio of Co to Ni to Cu to Cr to Fe to 1:1: 1 (0.5-1.5) of a pentabasic amorphous binder phase powder; then mixing the five-membered amorphous bonding phase powder with the W powder; and finally, filling the powder into a die for SPS sintering, and crystallizing the amorphous binding phase by a process of rapid heating and short-time heat preservation to finally prepare the tungsten-based high-specific gravity alloy of which the binding phase is the face-centered cubic structure high-entropy alloy. The problems of the technology are as follows: the prepared tungsten-based high-specific gravity alloy has lower density and poor mechanical property.

Disclosure of Invention

The invention solves the technical problems of lower density and poor mechanical property of the existing tungsten-based high-specific gravity alloy.

The invention adopts the following technical scheme to solve the technical problems:

the invention provides a preparation method of a multi-element doped high-specific gravity tungsten copper nickel alloy, which comprises the following steps:

(1) respectively weighing 88.5-90.5% of pure tungsten powder, 5% of copper powder, 3% of nickel powder, 0.5% of yttrium oxide powder, 0.5-1.5% of zirconium hydride powder and 0.5-1.5% of titanium powder according to weight percentage;

(2) stirring and ball-milling the raw material powder weighed in the step (1), and stirring and ball-milling for 18-24 hours under the argon atmosphere condition according to the ball-to-material ratio of 5:1 to prepare mixed powder;

(3) and (3) high-temperature sintering: putting the mixed powder subjected to ball milling in the step (2) into a graphite mould, putting the mould into a discharge plasma sintering furnace, introducing hydrogen into the furnace chamber, vacuumizing the furnace chamber at room temperature, heating to 600 ℃ at a heating rate of 100 ℃/min for 6min, preserving heat for 5min, and pressurizing to 20Mpa during heat preservation; then heating to 1050 ℃ at a heating rate of 100 ℃/min for 4.5min, pressurizing to 70MPa when heating, and keeping the temperature for 10 min; and then the temperature is reduced to room temperature at the cooling rate of 100 ℃/min, and the multielement doped high specific gravity tungsten-copper-nickel alloy is obtained.

According to the invention, trace yttrium oxide, zirconium and titanium alloy elements are doped in the alloy to generate solid solution strengthening and promote sintering densification, so that the sintered tungsten-copper-nickel alloy is completely densified, and the density can reach 16.5g/cm at most³Even more than 16.31g/cm³The theoretical density of (a); meanwhile, zirconium, titanium, copper and nickel have strong capability of forming quaternary alloy glass, and martensite phase transformation occurs under the condition of rapid cooling, and the zirconium, titanium, copper and nickel serve as second phase strengthening, so that the hardness can be further improved.

The invention simultaneously applies long-time high-energy ball milling to break the powder and refine the powder particles, thereby ensuring that the particle size of the powder particles is uniform.

Preferably, the purity of the pure tungsten powder is 99.8%, and the particle size is 1.8-2.2 μm.

Preferably, the copper powder has a purity of 99.9% and a particle size of 35 μm.

Preferably, the nickel powder has a purity of 99.9% and a particle size of 30 μm.

Preferably, the yttrium oxide powder has a purity of 99.8% and a particle size of 30 μm.

Preferably, the zirconium hydride powder has a purity of 99.9% and a particle size of 1 μm.

Preferably, the titanium powder has a purity of 99.7% and a particle size of 32.5 μm.

Preferably, the ball milling speed in the step (2) is 500 r/min.

Preferably, the flow rate of hydrogen in the step (3) is 0.15L/min.

The invention also provides the multielement-doped high-specific gravity tungsten-copper-nickel alloy prepared by the preparation method of the multielement-doped high-specific gravity tungsten-copper-nickel alloy.

The invention has the beneficial effects that:

(1) according to the invention, trace yttrium oxide, zirconium and titanium alloy elements are doped in the alloy to generate solid solution strengthening and promote sintering densification, so that the sintered tungsten-copper-nickel alloy is completely densified, and the density can reach 16.5g/cm at most³Even more than 16.31g/cm³The theoretical density of (1) is calculated on the premise that the element components are not dissolved mutually, but the nickel is dissolved in the tungsten phase and the copper phase in the invention, so the real theoretical density is a bit higher than the calculated theoretical density, and the false impression that the density exceeds 1 is caused; meanwhile, zirconium, titanium, copper and nickel have strong capability of forming quaternary alloy glass, and martensite phase transformation occurs under the condition of rapid cooling, and the zirconium, titanium, copper and nickel serve as second phase strengthening, so that the hardness can be further improved.

(2) The multi-element doping does not obviously reduce the density of the tungsten-copper-nickel alloy under the condition of greatly improving the hardness of the alloy, and the aim of improving the mechanical property of the tungsten-copper alloy material on the premise of maintaining higher density is fulfilled.

(3) The invention simultaneously applies long-time high-energy ball milling to break the powder and refine the powder particles, thereby ensuring that the particle size of the powder particles is uniform.

Drawings

FIG. 1 is a powder morphology graph after ball milling.

FIG. 2 is a surface scan of the powder after ball milling;

FIG. 3 is a microscopic surface topography of a multi-element doped high specific gravity tungsten copper nickel alloy under different magnifications;

FIG. 4 is a microscopic view of a multi-element doped high specific gravity tungsten copper nickel alloy fracture at different magnifications;

FIG. 5 is a cross-sectional view of the microstructure of a multi-element doped high specific gravity tungsten copper nickel alloy.

Detailed Description

The invention will be described in further detail below with reference to the drawings and examples of the specification.

Test materials, reagents and the like used in the following examples are commercially available unless otherwise specified.