High-strength antioxidant tungsten-copper-chromium composite material and preparation method thereof

Abstract

The invention discloses a high-strength antioxidant tungsten-copper-chromium composite material and a preparation method thereof, and belongs to the technical field of tungsten-copper composite materials. The mass of the required tungsten metal powder, the mass of the required copper metal powder and the mass of the required chromium metal powder are calculated according to the mass fractions of the designed components, and then weighing and proportioning are conducted for standby application; tungsten metal powder and chromium metal powder are subjected to mechanical alloying through a planetary ball mill to obtain tungsten-chromium alloy powder, then copper metal powder is added, ball milling continues to be conducted, and tungsten-copper-chromium composite powder is obtained; and the obtained tungsten-copper-chromium composite powder is subjected to cold pressing, and then the high-strength anti-oxidation tungsten-copper-chromium composite material is prepared through liquid-phase sintering. According to the preparation method of the high-strength anti-oxidation tungsten-copper-chromium composite material, compared with a tungsten-copper composite material under the same preparation condition, the tensile strength and the oxidation resistance of the prepared tungsten-copper-chromium composite material are synergistically improved.

Description

Technical Field

[0001] The present invention relates to the technical field of tungsten-copper composite materials, and in particular to a high-strength, oxidation-resistant tungsten-copper-chromium composite material and a preparation method thereof. Background Art

[0002] Tungsten copper composite material is a typical structural and functional integrated material. It has important applications in the aerospace field under high-temperature service environments due to its high temperature resistance, high strength, sweating cooling performance, erosion and ablation resistance and other characteristics. When in a high-temperature aerobic environment, the anti-oxidation performance of tungsten copper composite materials determines the service reliability and life of the parts, and its mechanical properties determine the load-bearing capacity of the parts.

[0003] At present, achieving high bearing capacity of tungsten-copper composite materials under tensile loads is still facing challenges. The reported methods for improving the tensile strength of tungsten-copper composite materials are usually only to improve the interfacial bonding of tungsten-copper phases, strengthen the copper phase or strengthen one of the tungsten phases. In addition, there are currently few methods for improving the oxidation resistance of tungsten-copper composite materials. Therefore, it is urgent to develop new composition and structural design methods, take into account the above-mentioned multiple aspects, and integrate multi-scale strengthening mechanisms to achieve the strengthening of tungsten-copper composite materials, as well as how to improve the oxidation resistance of tungsten-copper composite materials under aerobic conditions while maintaining excellent tensile strength. Therefore, the research and development of a tungsten-copper composite material with both high tensile strength and oxidation resistance is a technical challenge and research hotspot in this field. Summary of the invention

[0004] The purpose of the present invention is to provide a high-strength, oxidation-resistant tungsten-copper-chromium composite material and a preparation method thereof, so as to solve the problem that the tungsten-copper composite material mentioned in the background technology cannot maintain high oxidation resistance and excellent tensile strength under aerobic conditions, and obtain a new tungsten-copper composite material with both high tensile strength and excellent oxidation resistance to meet higher application requirements.

[0005] To achieve the above-mentioned purpose, the present invention provides a high-strength, oxidation-resistant tungsten-copper-chromium composite material. The chemical composition of the tungsten-copper-chromium composite material is as follows, by weight percentage: tungsten accounts for 63-71wt.% of the composite material, copper accounts for 28-32wt.% of the composite material, and chromium accounts for 1-5wt.% of the composite material.

[0006] The present invention also provides a method for preparing the above-mentioned high-strength oxidation-resistant tungsten-copper-chromium composite material, comprising the following steps: Step 1: Raw material preparation Calculate the mass of the required tungsten metal powder, copper metal powder and chromium metal powder according to the mass fraction of the designed components, and then weigh and proportion them for later use; Step 2: Preparation of composite powder Tungsten metal powder and chromium metal powder are mechanically alloyed by a planetary ball mill to obtain tungsten-chromium alloy powder, and then copper metal powder is added and continued to be ball-milled to obtain tungsten-copper-chromium composite powder; Step 3: Preparation of composite materials The composite powder obtained in step 2 is cold pressed and then liquid phase sintered to prepare a high-strength, oxidation-resistant tungsten-copper-chromium composite material.

[0007] Preferably, in step 1, the particle size of the tungsten metal powder is 1-5µm, and the purity is 99.9%; the particle size of the copper metal powder is 1-3µm, and the purity is 99.9%; the particle size of the chromium metal powder is ≤10µm, and the purity is 99.9%.

[0008] Preferably, in step 2, when preparing tungsten-chromium alloy powder, the ball milling time is 20-24h and the rotation speed is 500-560r / min.

[0009] Preferably, in step 2, when preparing the tungsten-copper-chromium composite powder, the ball milling time is 10-15 hours and the rotation speed is 260-310 r / min.

[0010] Preferably, both step 1 and step 2 are carried out in a glove box filled with high-purity argon.

[0011] Preferably, in step three, the pressure used for cold pressing the composite powder is 200-300 MPa.

[0012] Preferably, in step three, the liquid phase sintering conditions are: sintering at a temperature of 1200-1300° C. for 60-120 min.

[0013] Preferably, in step three, liquid phase sintering is carried out in a hydrogen atmosphere with a hydrogen flow rate of 150-200 mL / min.

[0014] Therefore, the high-strength, oxidation-resistant tungsten-copper-chromium composite material and its preparation method proposed in the present invention have the following specific beneficial effects: (1) The chromium element added in the present invention is an antioxidant element. The prepared tungsten-copper-chromium composite material exhibits better antioxidant properties in the range of 700-1000°C than the tungsten-copper composite material prepared under the same conditions, and has potential application prospects in high-temperature aerobic environments.

[0015] (2) The chromium element in the composite material prepared by the present invention exhibits a multi-scale distribution characteristic, wherein the dispersed chromium oxide particles, the nano-chromium-rich phase, the ultrafine grain structure of tungsten and the improvement of the bonding strength of tungsten grain boundaries play a strengthening role together.

[0016] (3) Compared with the tungsten-copper composite material prepared under the same preparation conditions, the tensile strength and oxidation resistance of the tungsten-copper-chromium composite material prepared by the present invention are synergistically improved.

[0017] (4) The preparation process of the present invention mainly involves ball milling and liquid phase sintering. The method is simple, easy and low-cost, and has wide applicability.

[0018] The technical solution of the present invention is further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 XRD patterns of tungsten-copper-chromium composite materials prepared by liquid phase sintering at 1200° C., 1250° C. and 1300° C. in Examples 1-3 of the present invention; Figure 2 Room temperature tensile stress-strain curves of the tungsten-copper-chromium composite materials prepared by liquid phase sintering at 1200° C., 1250° C. and 1300° C. in Examples 1-3 of the present invention and the tungsten-copper composite materials prepared by liquid phase sintering at 1200° C. and 1250° C. in Comparative Examples 1-2; Figure 3 The microstructure of the tungsten-copper-chromium composite material prepared by liquid phase sintering at 1200° C. in Example 1 of the present invention; Figure 4 The microscopic morphology of the tungsten phase in the tungsten-copper-chromium composite material prepared by liquid phase sintering at 1200° C. in Example 1 of the present invention; Figure 5 The microstructure of the tungsten-copper-chromium composite material prepared by liquid phase sintering at 1250° C. in Example 2 of the present invention; Figure 6 The microscopic morphology of the tungsten-copper-chromium composite material prepared by liquid phase sintering at 1300° C. in Example 3 of the present invention; Figure 7 Isothermal oxidation weight gain curves of the tungsten-copper-chromium composite material and the tungsten-copper composite material prepared by liquid phase sintering at 1200°C in Example 1 of the present invention and Comparative Example 1 at 700-1000°C. DETAILED DESCRIPTION

[0020] The technical solution of the present invention is further described below by means of the accompanying drawings and embodiments. It should be understood that these embodiments are only used to illustrate the present invention and are not used to limit the scope of the present invention. Any other changes, modifications, substitutions, combinations, simplifications made without violating the spirit and principle of the present invention should be equivalent replacement methods and are included in the protection scope of the present invention. In addition, it should be understood that after reading the content of the present invention, those skilled in the art can make various changes or modifications to the present invention, and these equivalent forms also fall within the scope defined by the claims attached to this application and belong to the scope of protection of the present invention.

[0021] Reference to "embodiment" herein means that the specific features, structures or characteristics described in conjunction with the embodiment may be included in at least one embodiment of the present application. The term "embodiment" appearing in various places in the specification does not necessarily refer to the same embodiment, nor does it particularly limit its independence or association with other embodiments. In principle, in the present application, as long as there is no technical contradiction or conflict, the various technical features mentioned in the embodiments can be combined in any way to form a corresponding implementable technical solution.

[0022] Unless otherwise defined, the technical terms used in this document have the same meanings as those generally understood by those skilled in the art to which this application belongs; the use of relevant terms in this document is only for describing specific embodiments and is not intended to limit this application.

[0023] Unless otherwise specified in the present invention, the reagents, instruments, and equipment used are those commonly used by technicians in this field.

[0024] Example 1 This embodiment provides a method for preparing a high-strength, oxidation-resistant tungsten-copper-chromium composite material under liquid phase sintering conditions at 1200° C. The specific steps are as follows: Step 1: Raw material preparation Tungsten metal powder, copper metal powder and chromium metal powder with a purity of 99.9% are used as raw materials, wherein the particle size of the tungsten metal powder is 1-5µm, the particle size of the copper metal powder is 1-3µm, and the particle size of the chromium metal powder is ≤10µm. The masses of the required tungsten, copper and chromium metal powders are calculated according to the mass percentage of the designed components, and are weighed and proportioned in a glove box filled with high-purity argon gas for use in preparing the composite material.

[0025] Step 2: Composite powder preparation The composite powder is prepared using a planetary ball mill. Tungsten and chromium metal powders are placed in a planetary ball mill for mechanical alloying to prepare tungsten-chromium alloy powder, wherein the ball milling time is 24 hours and the speed is 560r / min. Then copper metal powder is added to the tungsten-chromium alloy powder and the ball milling is continued for 10 hours at a speed of 310r / min to obtain tungsten-copper-chromium composite powder. The powder loading, powder scraping and powder screening operations are all carried out in a glove box filled with high-purity argon.

[0026] Step 3: Composite material preparation The tungsten-copper-chromium composite powder was cold-compacted into a disc shape under a pressure of 300 MPa, placed in an alumina crucible, and then placed in a tube furnace for liquid phase sintering, and sintered at 1200°C for 60 minutes to obtain a tungsten-copper-chromium composite material. The liquid phase sintering was carried out in a hydrogen atmosphere with a hydrogen flow rate of 200 mL / min.

[0027] Material mechanical property test and phase characterization: The room temperature tensile test of the alloy was conducted using a universal mechanical testing machine. The material was identified using an X-ray diffractometer (XRD). Small samples were cut from the composite material using wire cutting for thermogravimetric testing. The equipment used was a thermal analysis coupling system. The sample was first heated to the target temperature (700, 800, 900, 1000°C) under an Ar protective atmosphere, and then kept warm at the target temperature. Compressed air was introduced during the warming process, and the flow rate was controlled at 60mL / min. Figure 1 The XRD results of tungsten-copper-chromium composite material sintered at 1200℃ liquid phase show that the composite material is pure in phase. Figure 2 The room temperature tensile stress-strain curve of 1200℃ liquid phase sintered tungsten-copper-chromium composite material. The room temperature tensile strength of the composite material is about 729MPa. Figure 3 This is the microscopic morphology of tungsten-copper-chromium liquid phase sintered at 1200℃. The black contrast phase in the material is dispersed chromium oxide particles. Figure 4 The microstructure of the tungsten phase in the 1200℃ liquid phase sintered tungsten-copper-chromium composite material shows the presence of dispersed nano-chromium-rich phase inside it. Figure 7 The isothermal oxidation weight gain curves of tungsten-copper-chromium and tungsten-copper composite materials sintered at 1200℃ liquid phase at 700-1000℃. It can be seen that the oxidation rate of tungsten-copper-chromium composite materials is lower in this temperature range, and self-passivation phenomenon occurs at 700℃, with almost no weight gain as the oxidation time increases. This shows that the oxidation resistance of tungsten-copper-chromium composite materials is better in this temperature range.

[0028] Example 2 This embodiment provides a method for preparing a high-strength, oxidation-resistant tungsten-copper-chromium composite material under liquid phase sintering conditions at 1250° C. The specific steps are as follows: Step 1: Raw material preparation Tungsten metal powder, copper metal powder and chromium metal powder with a purity of 99.9% are used as raw materials, wherein the particle size of the tungsten metal powder is 1-5µm, the particle size of the copper metal powder is 1-3µm, and the particle size of the chromium metal powder is ≤10µm. The masses of the required tungsten, copper and chromium metal powders are calculated according to the mass percentage of the designed components, and are weighed and proportioned in a glove box filled with high-purity argon gas for use in preparing the composite material.

[0029] Step 2: Composite powder preparation The composite powder is prepared using a planetary ball mill. Tungsten and chromium metal powders are placed in a planetary ball mill for mechanical alloying to prepare tungsten-chromium alloy powder, wherein the ball milling time is 24 hours and the speed is 560r / min. Then copper metal powder is added to the tungsten-chromium alloy powder and the ball milling is continued for 10 hours at a speed of 310r / min to obtain tungsten-copper-chromium composite powder. The powder loading, powder scraping and powder screening operations are all carried out in a glove box filled with high-purity argon.

[0030] Step 3: Composite material preparation The tungsten-copper-chromium composite powder was cold-compacted into a disc shape under a pressure of 300 MPa, placed in an alumina crucible, and then placed in a tube furnace for liquid phase sintering, and sintered at 1250°C for 60 minutes to obtain a tungsten-copper-chromium composite material. The liquid phase sintering was carried out in a hydrogen atmosphere with a hydrogen flow rate of 200 mL / min.

[0031] Material mechanical property test and phase characterization: The room temperature tensile test of the alloy was conducted using a universal mechanical testing machine. XRD was used to identify the phase of the material. Figure 1 The XRD results of 1250℃ liquid phase sintered tungsten-copper-chromium composite material show that the composite material is pure in phase. Figure 2 The room temperature tensile stress-strain curve of 1250℃ liquid phase sintered tungsten-copper-chromium composite material. The room temperature tensile strength of the composite material is about 664MPa. Figure 5 This is the microscopic morphology of tungsten-copper-chromium liquid phase sintered at 1250℃. Chromium oxide particles are dispersed in the material, and there is a dispersed nano-chromium-rich phase inside the tungsten phase.

[0032] Example 3 This embodiment provides a method for preparing a high-strength, oxidation-resistant tungsten-copper-chromium composite material under liquid phase sintering conditions at 1300° C. The specific steps are as follows: Step 1: Raw material preparation Tungsten metal powder, copper metal powder and chromium metal powder with a purity of 99.9% are used as raw materials, wherein the particle size of the tungsten metal powder is 1-5µm, the particle size of the copper metal powder is 1-3µm, and the particle size of the chromium metal powder is ≤10µm. The masses of the required tungsten, copper and chromium metal powders are calculated according to the mass percentage of the designed components, and are weighed and proportioned in a glove box filled with high-purity argon gas for use in preparing the composite material.

[0033] Step 2: Composite powder preparation The composite powder is prepared using a planetary ball mill. Tungsten and chromium metal powders are placed in a planetary ball mill for mechanical alloying to prepare tungsten-chromium alloy powder, wherein the ball milling time is 24 hours and the speed is 560r / min. Then copper metal powder is added to the tungsten-chromium alloy powder and the ball milling is continued for 10 hours at a speed of 310r / min to obtain tungsten-copper-chromium composite powder. The powder loading, powder scraping and powder screening operations are all carried out in a glove box filled with high-purity argon.

[0034] Step 3: Composite material preparation The tungsten-copper-chromium composite powder was cold-compacted into a disc shape under a pressure of 300 MPa, placed in an alumina crucible, and then placed in a tube furnace for liquid phase sintering, and sintered at 1300°C for 60 minutes to obtain a tungsten-copper-chromium composite material. The liquid phase sintering was carried out in a hydrogen atmosphere with a hydrogen flow rate of 200 mL / min.

[0035] Material mechanical property test and phase characterization: The room temperature tensile test of the alloy was conducted using a universal mechanical testing machine. XRD was used to identify the phase of the material. Figure 1 The XRD results of tungsten-copper-chromium composite material sintered at 1300℃ liquid phase show that the composite material is pure in phase. Figure 2 The room temperature tensile stress-strain curve of tungsten-copper-chromium composite material sintered at 1300℃ liquid phase. The room temperature tensile strength of the composite material is about 652MPa. Figure 6 This is the microscopic morphology of tungsten-copper-chromium liquid phase sintered at 1300℃. Chromium oxide particles are dispersed in the material, and there is a dispersed nano-chromium-rich phase in the tungsten phase.

[0036] Comparative Example 1 This comparative example provides a method for preparing a tungsten-copper composite material under liquid phase sintering conditions at 1200° C., and the specific steps are as follows: Step 1: Raw material preparation Tungsten metal powder and copper metal powder with a purity of 99.9% are used as raw materials, wherein the particle size of the tungsten metal powder is 1-5μm, and the particle size of the copper metal powder is 1-3μm. The masses of the required tungsten, copper and chromium metal powders are calculated according to the mass percentage of the designed components, and are weighed and proportioned in a glove box filled with high-purity argon for use in preparing composite materials.

[0037] Step 2: Composite powder preparation The composite powder is prepared using a planetary ball mill. The tungsten metal powder is ball-milled separately, and the tungsten metal powder is ball-milled separately in an argon protective atmosphere using a planetary ball mill for 24 hours at a speed of 560r / min. Then, the ball-milled tungsten metal powder and copper metal powder are ball-milled and mixed in an argon protective atmosphere for 10 hours at a speed of 310r / min to obtain a tungsten-copper composite powder. The proportions of tungsten and copper in the tungsten-copper composite powder are 70wt.% and 30wt.% respectively; the powder loading, powder scraping, and powder screening operations are all carried out in a glove box filled with high-purity argon.

[0038] Step 3: Composite material preparation The tungsten-copper composite powder was cold-compacted into a disc shape under a pressure of 300 MPa, placed in an alumina crucible, and then placed in a tube furnace for liquid phase sintering, and sintered at 1200°C for 60 minutes to obtain a tungsten-copper composite material. The liquid phase sintering was carried out in a hydrogen atmosphere with a hydrogen flow rate of 200 mL / min.

[0039] Material mechanical properties testing and phase characterization: The room temperature tensile test of the alloy was conducted using a universal mechanical testing machine. Figure 2 The room temperature tensile stress-strain curve of 1200℃ liquid phase sintered tungsten-copper composite material. The room temperature tensile strength of the composite material is about 630MPa. Figure 7 The isothermal oxidation weight gain curves of tungsten-copper-chromium and tungsten-copper composite materials sintered at 1200℃ liquid phase at 700-1000℃. It can be seen that compared with the tungsten-copper-chromium composite material sintered at 1200℃, the oxidation weight gain of the tungsten-copper composite material in this temperature range is faster, indicating that the tungsten-copper composite material has lower oxidation resistance.

[0040] Comparative Example 2 This comparative example provides a method for preparing a tungsten-copper composite material under liquid phase sintering conditions at 1250°C, and the specific steps are as follows: Step 1: Raw material preparation Tungsten metal powder and copper metal powder with a purity of 99.9% are used as raw materials, wherein the particle size of the tungsten metal powder is 1-5μm, and the particle size of the copper metal powder is 1-3μm. The masses of the required tungsten, copper and chromium metal powders are calculated according to the mass percentage of the designed components, and are weighed and proportioned in a glove box filled with high-purity argon for use in preparing composite materials.

[0041] Step 2: Composite powder preparation The composite powder is prepared using a planetary ball mill. The tungsten metal powder is ball-milled separately, and the tungsten metal powder is ball-milled separately in an argon protective atmosphere using a planetary ball mill for 24 hours at a speed of 560r / min. Then, the ball-milled tungsten metal powder and copper metal powder are ball-milled and mixed in an argon protective atmosphere for 10 hours at a speed of 310r / min to obtain a tungsten-copper composite powder. The proportions of tungsten and copper in the tungsten-copper composite powder are 70wt.% and 30wt.% respectively; the powder loading, powder scraping, and powder screening operations are all carried out in a glove box filled with high-purity argon.

[0042] Step 3: Composite material preparation The tungsten-copper composite powder was cold-compacted into a disc shape under a pressure of 300 MPa, placed in an alumina crucible, and then placed in a tube furnace for liquid phase sintering, and sintered at 1250°C for 60 minutes to obtain a tungsten-copper composite material. The liquid phase sintering was carried out in a hydrogen atmosphere with a hydrogen flow rate of 200 mL / min.

[0043] Material mechanical properties testing and phase characterization: The room temperature tensile test of the alloy was conducted using a universal mechanical testing machine. Figure 2 The room temperature tensile stress-strain curve of 1250℃ liquid phase sintered tungsten-copper composite material. The room temperature tensile strength of the composite material is about 613MPa.

[0044] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that they can still modify or replace the technical solution of the present invention with equivalents, and these modifications or equivalent replacements cannot cause the modified technical solution to deviate from the spirit and scope of the technical solution of the present invention.

Claims

1. A high-strength, oxidation-resistant tungsten-copper-chromium composite material, characterized in that: The chemical composition of the tungsten-copper-chromium composite material is as follows: tungsten accounts for 63-71wt.% of the composite material, copper accounts for 28-32wt.% of the composite material, and chromium accounts for 1-5wt.% of the composite material.

2. The method for preparing a high-strength, oxidation-resistant tungsten-copper-chromium composite material according to claim 1, characterized in that: The following steps are involved: Step 1: Raw material preparation Calculate the mass of the required tungsten metal powder, copper metal powder and chromium metal powder according to the mass fraction of the designed components, and then weigh and proportion them for later use; Step 2: Preparation of composite powder The tungsten metal powder and the chromium metal powder are mechanically alloyed by a planetary ball mill to obtain a tungsten-chromium alloy powder, and then copper metal powder is added and continued to be ball-milled to obtain a tungsten-copper-chromium composite powder; Step 3: Preparation of composite materials The composite powder obtained in step 2 is cold pressed and then liquid phase sintered to prepare a high-strength, oxidation-resistant tungsten-copper-chromium composite material.

3. The method for preparing a high-strength, oxidation-resistant tungsten-copper-chromium composite material according to claim 2, characterized in that: In step 1, the particle size of the tungsten metal powder is 1-5µm, and the purity is 99.9%; the particle size of the copper metal powder is 1-3µm, and the purity is 99.9%; the particle size of the chromium metal powder is ≤10µm, and the purity is 99.9%.

4. The method for preparing a high-strength, oxidation-resistant tungsten-copper-chromium composite material according to claim 2, characterized in that: In step 2, when preparing tungsten-chromium alloy powder, the ball milling time is 20-24 hours and the rotation speed is 500-560r / min.

5. The method for preparing a high-strength, oxidation-resistant tungsten-copper-chromium composite material according to claim 2, characterized in that: In step 2, when preparing tungsten-copper-chromium composite powder, the ball milling time is 10-15 hours and the rotation speed is 260-310 r / min.

6. The method for preparing a high-strength, oxidation-resistant tungsten-copper-chromium composite material according to claim 2, characterized in that: Both step 1 and step 2 are carried out in a glove box filled with high-purity argon.

7. The method for preparing a high-strength, oxidation-resistant tungsten-copper-chromium composite material according to claim 2, characterized in that: In step 3, the pressure used for cold pressing the composite powder is 200-300 MPa.

8. The method for preparing a high-strength, oxidation-resistant tungsten-copper-chromium composite material according to claim 2, characterized in that: In step three, the liquid phase sintering conditions are: sintering at a temperature of 1200-1300° C. for 60-120 minutes.

9. The method for preparing a high-strength, oxidation-resistant tungsten-copper-chromium composite material according to claim 2, characterized in that: In step three, liquid phase sintering is carried out in a hydrogen atmosphere with a hydrogen flow rate of 150-200 mL / min.

Images