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CN-117265436-B - Aluminum nitride-plated short tungsten fiber toughened tungsten-based composite material and preparation method thereof

CN117265436BCN 117265436 BCN117265436 BCN 117265436BCN-117265436-B

Abstract

The invention provides an aluminum nitride-plated short tungsten fiber toughened tungsten-based composite material and a preparation method thereof. The matrix of the composite material is a tungsten matrix, the toughening body is short tungsten fiber with an aluminum nitride plating layer on the surface, and the addition amount of the aluminum nitride plating short tungsten fiber is 10% -50% (vol.%). Preparing an aluminum nitride coating on the surface of the short tungsten fiber by adopting a surface plating technology, ball-milling and mixing the short tungsten fiber coated with aluminum nitride and raw material powder according to a certain proportion, and sintering by adopting a spark plasma sintering technology, wherein the sintering temperature is 1500-2000 ℃, the sintering pressure is 50-80 MPa, and the heat preservation and pressure maintaining time is 1-5 min. The aluminum nitride-plated short tungsten fiber toughened tungsten-based composite material can simultaneously improve the mechanical property and the heat conducting property of the tungsten material, and has the toughness and the rapid heat conducting capability required by being used as a plasma-oriented material.

Inventors

  • HUANG JIHUA
  • CHEN SHUAI
  • YE ZHENG
  • YANG JIAN
  • WANG WANLI

Assignees

  • 北京科技大学

Dates

Publication Date
20260505
Application Date
20231010

Claims (9)

  1. 1. The aluminum nitride-plated short tungsten fiber toughened tungsten-based composite material is characterized in that a substrate is a tungsten W substrate, a toughening body is a short tungsten fiber W f with an aluminum nitride AlN coating on the surface, wherein the addition of the aluminum nitride-plated short tungsten fiber W f @AlN is 10% -50% by volume, and the addition of an activated sintering element in the substrate is 0% -1.0% by mass; the preparation method of the aluminum nitride-plated short tungsten fiber toughened tungsten-based composite material comprises the following steps: 1) Preparing an AlN coating on the surface of an original short fiber W f by adopting a surface coating technology to obtain an AlN-coated short fiber W f , wherein the original short fiber W f is a potassium-doped tungsten fiber, the diameter is 50-250 mu m, the length is 1-4 mm, and the content of potassium element is 50-80 ppm; 2) Preparing AlN-plated short fibers W f , W powder and activated sintering element powder according to a certain proportion, wherein the addition amount of the AlN-plated short fibers W f is 10-50% by volume percent, the addition amount of the activated sintering element is 0-1.0% by mass percent, uniformly mixing the raw materials by adopting a ball milling process to obtain mixed powder, and performing densification sintering to obtain the AlN-plated short fibers W f toughened W-based composite material.
  2. 2. The aluminum nitride-plated short tungsten fiber toughened tungsten-based composite material according to claim 1, wherein the activated sintering elements in the matrix comprise iron powder, nickel powder, cobalt powder, aluminum powder and palladium powder, and the addition amount is 0.1% -1.0% by mass.
  3. 3. The method for preparing the aluminum nitride-plated short tungsten fiber toughened tungsten-based composite material according to claim 1, comprising the following steps: Preparation of AlN-plated short fiber W f in step (1) A. Carrying out ultrasonic cleaning on the original short fiber W f by absolute ethyl alcohol or acetone, and then carrying out vacuum drying; b. Preparing an AlN coating on the surface of the original short fiber W f by adopting a magnetron sputtering and chemical vapor deposition surface plating technology to obtain an AlN-coated short fiber W f ; The magnetron sputtering technology is adopted, a certain amount of original short fibers W f are placed on a substrate disc with a rotating function in a device cavity to be sputtered, a target is a pure aluminum target, the temperature of the substrate short fibers W f is 300-450 ℃, the distance between the target and the substrate is 40-60 mm, the sputtering power is 150-450W, the sputtering atmosphere is a high-purity Ar/N 2 mixed atmosphere, the flow ratio of Ar to N 2 is 1:4-4:1, the sputtering air pressure is 0.5-2 Pa, and the sputtering time is 2-20 h; The chemical vapor deposition technology is adopted, a certain amount of original short fibers W f are placed on a substrate disc with a rotating function in a device cavity for deposition, precursors are gaseous AlCl 3 and NH 3 , the deposition temperature is 600-800 ℃, the flow ratio of the gaseous AlCl 3 to the NH 3 is 1:4-1:1, the deposition time is 0.5-5 h, and the steps are that (2) Preparation of AlN-plated short fiber W f toughened W-based composite material A. Preparing AlN-plated short fibers W f , W powder and activated sintering element powder according to a certain proportion, wherein the addition amount of the AlN-plated short fibers W f is 10-50% by volume percent, the addition amount of the activated sintering element is 0-1.0% by mass percent, and uniformly mixing the raw materials by adopting a ball milling process to obtain mixed powder; b. And (3) performing densification sintering on the mixed powder, and sintering the mixed powder by adopting a spark plasma sintering process, wherein the sintering temperature is 1500-2000 ℃, the sintering pressure is 50-80 MPa, and the heat preservation and pressure maintaining time is 1-5 min, so as to obtain the AlN-plated short fiber W f toughened W-based composite material.
  4. 4. The method for preparing an aluminum nitride-plated short tungsten fiber toughened tungsten-based composite material according to claim 3, wherein in the step (2) a, the particle size of the W powder is 500 nm-10 μm, and the particle size of the activated sintering element powder is 1-5 μm.
  5. 5. The method for preparing the aluminum nitride-plated short tungsten fiber toughened tungsten-based composite material according to claim 3, wherein in the step (2), when raw materials are subjected to ball milling and mixing, the materials of a ball milling tank and a grinding ball are hard alloy, W powder and AlN-plated short fiber W f are placed in the ball milling tank according to a proportion, the ball milling time is 0.5-1 h, the rotating speed is 50-150 r/min, when activated sintering element powder is required to be added, the W powder and the activated sintering element powder are placed in the ball milling tank according to a proportion, the ball material ratio is 2:1-8:1, the ball milling time is 2-10 h, the rotating speed is 150-300 r/min, then AlN-plated short fiber W f is placed in the ball milling tank according to a proportion, the ball material ratio is 1:4-2:1, and the ball milling time is 0.5-1 h, and the rotating speed is 50-150 r/min.
  6. 6. The method for preparing the aluminum nitride-plated short tungsten fiber toughened tungsten-based composite material according to claim 3, wherein in the step (2) a, high-purity Ar is filled in a ball milling tank as a protective atmosphere during raw material mixing, and in the step (2) b, the high-purity Ar is adopted as the protective atmosphere in the whole process of spark plasma sintering.
  7. 7. The method for preparing the aluminum nitride-plated short tungsten fiber toughened tungsten-based composite material according to claim 3, wherein in the step (2) b, the spark plasma sintering process is carried out at a temperature rising rate of 50-100 ℃ per minute to a target temperature, the sintering pressure is synchronously loaded to the target pressure along with the temperature rising process, the heat preservation process and the pressure maintaining process are synchronously carried out, and then the furnace is cooled, and meanwhile, the pressure is unloaded.
  8. 8. The method for preparing the aluminum nitride-plated short tungsten fiber toughened tungsten-based composite material according to claim 3, wherein the sintering temperature is lower than 1800 ℃, activated sintering element powder comprising iron powder, nickel powder, cobalt powder, aluminum powder and palladium powder is added into the W matrix, and the addition amount of the activated sintering element powder is 0.1-1.0% by mass percent.
  9. 9. The aluminum nitride-plated short tungsten fiber toughened tungsten-based composite material according to any one of claims 1-2 for high-performance tungsten-based structural materials, particularly for plasma-oriented materials of nuclear fusion reactors.

Description

Aluminum nitride-plated short tungsten fiber toughened tungsten-based composite material and preparation method thereof Technical Field The invention relates to the technical field of preparing high-performance tungsten-based composite materials by a powder metallurgy process, in particular to an aluminum nitride-plated short tungsten fiber toughened tungsten-based composite material and a preparation method thereof. Background The tungsten and the alloy thereof have a series of advantages of high melting point, low thermal expansion coefficient, low sputtering corrosion rate, low deuterium-tritium retention rate and the like, and are regarded as candidate materials facing to plasma materials of a nuclear fusion reactor in the future. However, the brittleness problem of metallic tungsten materials severely limits its application in this field. The plasma-oriented material is subjected to larger heat load in the service process, and thermal stress caused by temperature gradient exists in the plasma-oriented material, so that the brittle tungsten material can be cracked under the action of the larger heat stress. Alloying, particle strengthening, and fine grain strengthening are conventional methods for solving the problem of brittleness of tungsten materials. However, under high heat flux and neutron irradiation, the internal toughening mechanism described above will gradually fail. Therefore, tungsten materials prepared by the internal toughening process are not suitable for long-term service as plasma-oriented materials. In order to solve the problem, researchers at home and abroad adopt a fiber toughening technology to prepare a tungsten fiber (W f) toughened tungsten-based (W f/W composite material). Based on an external toughening mechanism, the composite material realizes energy dissipation mechanisms such as crack deflection, crack bridging, fiber debonding, fiber pulling and the like by introducing a tungsten fiber toughening body into a tungsten matrix, so that the toughness of the composite material is improved. Common tungsten fiber toughening bodies include long tungsten fibers, tungsten fiber meshes, three-dimensional tungsten filament braiding bodies and short tungsten fibers. The Rui Shu et al prepares a long-fiber W f/W composite material by taking a long-tungsten fiber as a toughening body, and a mechanical property test result shows that the composite material has higher bending strength and obvious 'pseudo plasticity' characteristics [ R.Shu, Y.Mao, J.W.Coenen, A.Terra, C.Liu, S ].J.Riesch,C.Linsmeier,C.Broeckmann,Interface and mechanical properties of the single-layer long fiber reinforced Wf/W composites fabricated via field assisted sintering technology,Mater.Sci.Eng.A.857(2022)144098]. Wang Shan, xie Mengyu et al prepared a fiber web W f/W composite material with a tungsten fiber web as a toughening body, and compared with a pure W material, the toughness of the composite material is improved by 60% -80% [ a layered fiber toughened tungsten-based composite material and a preparation method thereof, with publication number of CN 112442643A ]. Yan Binyou, song Jiupeng and the like prepare a fiber woven body W f/W composite material by taking a three-dimensional tungsten wire woven body as a toughening body, and mechanical property test results show that the composite material has excellent room-temperature three-dimensional strength and room-temperature three-dimensional toughness [ a preparation method of a tungsten wire reinforced tungsten-based composite material, with the publication number of CN 115404419A ]. However, the long-fiber W f/W composite material or the fiber web W f/W composite material prepared by taking long-tungsten fibers or the tungsten fiber web as a toughening body has the problem of anisotropic mechanical properties, the directions perpendicular to the long-tungsten fibers or the tungsten fiber web are weak directions of the mechanical properties of the two composite materials respectively, the preparation process of the material is complicated, the long-tungsten fibers/tungsten fiber web and tungsten powder are required to be layered and laid manually in advance, and then sintering is carried out, so that the quality stability of the product cannot be ensured. Although the fiber woven body W f/W composite material prepared by taking the three-dimensional tungsten wire woven body as the toughening body realizes the improvement of the toughness of the material in the three-dimensional direction, the three-dimensional tungsten wire woven body is required to be prepared in advance, and the process flow is also more complicated. The short-fiber W f/W composite material prepared by taking the short-tungsten fiber as the toughening body has the advantages of simple preparation process, isotropy of mechanical property, high stability of product quality and the like, and is the main direction of research and development of the current W f/W composite material. Another ke