阅读说明：本技术 一种钨-含能高熵合金复合材料及其制备方法 (Tungsten-energetic high-entropy alloy composite material and preparation method thereof ) 是由 梁耀健 王本鹏 薛云飞 于 2020-05-25 设计创作，主要内容包括：本发明涉及一种钨-含能高熵合金复合材料及其制备方法,属于钨合金材料技术领域。本发明所述的复合材料由以BCC结构为主的含能高熵合金基体相和钨增强相组成,两相界面结合良好且无金属间化合物形成,兼具高强度、较高的断裂应变和高释能特性,而且可以实现密度在大范围内调整,综合性能优异；另外,所述复合材料的制备工艺简单,生成效率高,易于工业化生产。(The invention relates to a tungsten-energetic high-entropy alloy composite material and a preparation method thereof, belonging to the technical field of tungsten alloy materials. The composite material consists of an energy-containing high-entropy alloy matrix phase and a tungsten reinforced phase which take a BCC structure as a main component, has good combination of two phase interfaces and no intermetallic compound, has the characteristics of high strength, higher fracture strain and high energy release, can realize the adjustment of density in a large range, and has excellent comprehensive performance; in addition, the preparation process of the composite material is simple, the generation efficiency is high, and the industrial production is easy to realize.)

1. A tungsten-energetic high-entropy alloy composite material is characterized in that: the composite material takes energetic high-entropy alloy as a matrix phase and takes tungsten as a reinforcing phase, wherein the mass percentage of the tungsten phase is 40-98%;

the energetic high-entropy alloy takes a BCC structure as a main phase, and the theoretical energy density is more than or equal to 80kJ/cm³The dynamic compression strength is more than or equal to 1200MPa, and the fracture strain is more than or equal to 30 percent.

2. A tungsten-energetic high entropy alloy composite material as claimed in claim 1, wherein: the atomic percent expression of the energetic high-entropy alloy is recorded as Zr_aTi_bHf_cM_dN_xM is at least one of Nb, Ta and V, N is at least one of Al, Cr, Fe, Mo, Mg, Be, Li, Co, Ni, N, Si, B, C, N and O, a is more than 0 and less than or equal to 45, B is more than or equal to 5 and less than or equal to 65, C is more than or equal to 0 and less than or equal to 35, d is more than or equal to 10 and less than or equal to 55, x is more than or equal to 0 and less than or equal to 10, and a + B + C + d + x is 100.

3. A method for preparing the tungsten-energetic high-entropy alloy composite material as defined in claim 1 or 2, characterized in that: the steps of the method are as follows,

(1) under the protection of argon, carrying out alloying smelting on metal simple substances corresponding to each element in the energy-containing high-entropy alloy, and carrying out gas atomization powder preparation after the alloy is completely melted into alloy liquid to obtain energy-containing high-entropy alloy powder;

(2) adding the energetic high-entropy alloy powder and the tungsten raw material into a ball mill according to a design proportion, and uniformly mixing under the protection of argon to obtain composite powder;

(3) and (2) pressing and molding the composite powder under the pressure of 150-300 MPa, sintering the pressed and molded blank in an argon atmosphere, wherein the sintering temperature is 20-100 ℃ higher than the melting point of the energetic high-entropy alloy, and preserving heat for 0.5-2 h at the sintering temperature to obtain the tungsten-energetic high-entropy alloy composite material.

4. The method for preparing the tungsten-energetic high-entropy alloy composite material according to claim 3, characterized in that: the technological parameters of the gas atomization powder preparation in the step (1) are as follows: the pressure of atomizing gas is 2 MPa-8 MPa, the atomizing power is 100 kW-200 kW, and the atomizing medium adopts argon.

5. The method for preparing the tungsten-energetic high-entropy alloy composite material according to claim 3, characterized in that: the shape of the tungsten raw material is spherical, filamentous or skeleton structure.

6. The method for preparing the tungsten-energetic high-entropy alloy composite material according to claim 3, characterized in that: when the materials are mixed in the ball milling in the step (2), the ball-material ratio is 5: 1-10: 1, the ball milling rotating speed is 100 r/min-300 r/min, and the ball milling time is 10 h-24 h.

Technical Field

The invention relates to a tungsten-energetic high-entropy alloy composite material and a preparation method thereof, belonging to the technical field of tungsten alloy materials.

Background

The tungsten alloy is a composite material which takes metal tungsten as a reinforcing phase and takes NiFe, Cu, Zr or other low-melting-point elements as a matrix phase, has a series of advantages of high density, high strength and the like, and is widely applied to gyro motor rotors, tool vibration damping blocks, chopping blocks, warhead materials and the like.

By virtue of the high density and high strength of tungsten,and combines the high-release energy of zirconium to develop a tungsten-zirconium alloy with high strength and high-release energy. In the process of high-speed penetration of the tungsten-zirconium alloy into a target, the tungsten-zirconium alloy can penetrate through the target by using the high strength of the tungsten-zirconium alloy, and can also violently release energy by using the reaction of active element zirconium and oxygen, so that the target is comprehensively damaged by penetration and deflagration, and the damage power is greatly improved. However, W is easily generated at the interface of W-Zr alloy₂The Zr intermetallic compound can ensure that the mechanical property of the tungsten-zirconium alloy is rapidly deteriorated (no macroscopic plasticity) and is difficult to bear detonation loading on one hand, and the Zr intermetallic compound can sacrifice part of active element zirconium on the other hand, thereby reducing the energy release efficiency.

Disclosure of Invention

Aiming at the defects of the existing tungsten alloy, the invention provides a tungsten-energetic high-entropy alloy composite material and a preparation method thereof, wherein the composite material consists of an energetic high-entropy alloy matrix phase and a tungsten reinforcing phase, and an intermetallic compound is not formed on a two-phase interface, so that the composite material has the characteristics of high strength, higher fracture strain and high energy release, can realize the adjustment of the density in a large range, and has excellent comprehensive performance; the composite material has simple preparation process and high generation efficiency, and is easy for industrial production.

The purpose of the invention is realized by the following technical scheme.

The tungsten-energy-containing high-entropy alloy composite material takes energy-containing high-entropy alloy as a matrix phase and tungsten as a reinforcing phase, wherein the mass percentage of the tungsten phase is 40-98%.

The energetic high-entropy alloy takes a BCC structure as a main phase, and the theoretical energy density is more than or equal to 80kJ/cm³The dynamic compression strength is more than or equal to 1200MPa, and the fracture strain is more than or equal to 30 percent.

Preferably, the atomic percent expression of the energy-containing high-entropy alloy is recorded as Zr_aTi_bHf_cM_dN_xM is at least one of Nb, Ta and V, N is at least one of Al, Cr, Fe, Mo, Mg, Be, Li, Co, Ni, N, Si, B, C, N and O, a is more than 0 and less than or equal to 45, B is more than or equal to 5 and less than or equal to 65, C is more than or equal to 0 and less than or equal to 35, d is more than or equal to 10 and less than or equal to 55, x is more than or equal to 0 and less than or equal to 10, and a + B + C + d + x is 100.

The invention relates to a preparation method of a tungsten-energetic high-entropy alloy composite material, which comprises the following steps:

(1) under the protection of argon, carrying out alloying smelting on metal simple substances corresponding to each element in the energy-containing high-entropy alloy, and carrying out gas atomization powder preparation after the alloy is completely melted into alloy liquid to obtain energy-containing high-entropy alloy powder;

(2) adding the energetic high-entropy alloy powder and the tungsten raw material into a ball mill according to a design proportion, and uniformly mixing under the protection of argon to obtain composite powder;

(3) and (2) pressing and molding the composite powder under the pressure of 150-300 MPa, sintering the pressed and molded blank in an argon atmosphere, wherein the sintering temperature is 20-100 ℃ higher than the melting point of the energetic high-entropy alloy, and preserving heat for 0.5-2 h at the sintering temperature to obtain the tungsten-energetic high-entropy alloy composite material.

Preferably, the technological parameters of the gas atomization powder preparation in the step (1) are as follows: the pressure of atomizing gas is 2 MPa-8 MPa, the atomizing power is 100 kW-200 kW, and the atomizing medium adopts argon.

Preferably, the morphology of the tungsten feedstock is spherical, filamentous, or skeletal.

Preferably, when the materials are mixed in the ball milling in the step (2), the ball-material ratio is 5: 1-10: 1, the ball milling rotation speed is 100 r/min-300 r/min, and the ball milling time is 10 h-24 h.

Has the advantages that:

(1) the composite material takes the energy-containing high-entropy alloy with a BCC structure as a main matrix phase and tungsten as a reinforcing phase, the two-phase interface is well combined and no intermetallic compound is formed, so that the good mechanical property is ensured, the energy release property of the energy-containing high-entropy alloy is reserved, and the energy release threshold value of the composite material is obviously reduced compared with that of the energy-containing high-entropy alloy; in addition, the density of the composite material can be adjusted in a large range by adjusting the proportion of the two phases;

(2) the composite material has a large number of uniformly distributed two-phase interfaces, so that the energy release efficiency of the energy-containing high-entropy alloy can be obviously improved;

(3) the invention adopts the technology of gas atomization powder preparation combined with the water-cooled copper crucible to realize the preparation of the energy-containing high-entropy alloy powder, and the preparation of the composite material is realized by utilizing the powder metallurgy technology, so that the process is simple, the generation efficiency is high, and the industrial generation is easy.

Drawings

FIG. 1 is a 50 wt.% W/Nb sample prepared in example 1₁₇Zr₂₁Ti₆₂Composite and 80 wt.% W/Nb prepared in example 2₁₇Zr₂₁Ti₆₂X-ray diffraction (XRD) contrast pattern of the composite.

FIG. 2 is the 50 wt.% W/Nb prepared in example 1₁₇Zr₂₁Ti₆₂A micro-topography of the composite.

FIG. 3 is the 93 wt.% W/Ti prepared in example 3₄₀V₂₀Ta₃₅Zr₄And (3) a micro-topography of the Cr composite material.

FIG. 4 is a comparison graph of the dynamic compressive true stress-strain curves of the composites prepared in examples 1-3.

Detailed Description

The invention is further illustrated by the following figures and detailed description, wherein the process is conventional unless otherwise specified, and the starting materials are commercially available from a public disclosure without further specification.

1) Reagent and apparatus

The information on the main reagents used in the following examples is shown in Table 1 and the information on the main instruments and equipments is shown in Table 2.

TABLE 1

TABLE 2

2) Performance testing and structural characterization

(1) And (3) density measurement: according to standard GB-5365-2005, the density of the composite material is tested by adopting a DT-100 precision balance, and the size of a sample is phi 4 multiplied by 4 mm.

(2) Phase analysis: the phase analysis was carried out using a Bruker AXS D8 advanced X-ray diffractometer in Germany, operating voltage and current were 40kV and 40mA, respectively, the X-ray source was CuKa (λ 0.1542nm) radiation, the scanning speed was 0.2sec/step, the scanning step was 0.02 °/step, and the scanning range was 20 ° to 100 °.

(3) And (3) appearance observation: the microstructure characterization was performed by using a HITACHI S4800 model cold field emission scanning electron microscope from Hitachi, Japan, and the backscattered electron imaging was performed at a working voltage of 15 kV.

(4) Dynamic compression test, according to standard GJB-5365-2005, the room temperature axial dynamic compression mechanical property of the composite material is tested by adopting a Separated Hopkins Pressure Bar (SHPB), the size of the test sample is phi 4 × 4mm, and the strain rate is-10³s^-1。

(5) Energy release characteristics: the SHPB device is adopted to load the composite material at a high speed, the strain rate is gradually increased until the composite material generates fire light, the corresponding strain rate is the energy release threshold value of the composite material, and the lower the energy release threshold value is, the easier the composite material can release energy.