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A kind of nanocrystalline tungsten alloy and preparation method thereof

A tungsten alloy and nanocrystalline technology, which is applied in the field of nanocrystalline tungsten alloy and its preparation, can solve the problems of inability to prepare bulk nanocrystalline tungsten materials, and achieve the effect of inhibiting the growth of grains and promoting the densification of materials

Active Publication Date: 2021-05-21
PEKING UNIV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

The top-down method refines the grains and prepares nanocrystalline tungsten bulk materials by performing deep plastic deformation on coarse-grained bulk tungsten materials. This method includes equal channel angular extrusion (ECAE), High-pressure torsion (HPT), cumulative compound rolling (ARB) and surface mechanical grinding treatment (SMAT), etc.; the bottom-up method is to prepare tungsten powder by high-energy ball milling method, wet chemical method, etc., and then tungsten powder simultaneously Doping the second phase particle powder for sintering, including spark plasma sintering, hot isostatic pressing sintering, microwave sintering, etc., none of these methods can prepare bulk nanocrystalline tungsten materials

Method used

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  • A kind of nanocrystalline tungsten alloy and preparation method thereof
  • A kind of nanocrystalline tungsten alloy and preparation method thereof

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Experimental program
Comparison scheme
Effect test

Embodiment 1

[0027] Step 1: Put tungsten powder and yttrium oxide powder into a ball mill jar under a nitrogen atmosphere in a glove box (the purity of nitrogen is 99.999%), and the doping ratio of the second phase particle powder is 1 wt%. The average particle size of the second phase nanoparticles is 37nm, as figure 1 (a) shows the SEM image of yttrium oxide nanoparticles.

[0028] Step 2: Add grinding balls into the ball milling jar, the ratio of the mass of the balls to the mass of the powder is 30:1, add a sealing rubber ring on the ball milling jar, cover the lid of the ball milling jar, and close the air valve of the ball milling jar.

[0029] Step 3: Put the ball mill jar into the ball mill for high-energy ball milling, the ball mill speed is set to 400rpm, the ball milling time is 8h, and the size of the balls is 1mm. The grain size of the powder is refined by high-energy ball milling, and the yttrium oxide particles and tungsten powder are mixed uniformly at the same time.

[0...

Embodiment 2

[0036] Step 1: Put tungsten powder and yttrium powder into a ball mill jar under an inert gas atmosphere in a glove box (the purity of the inert gas is 99.999%), the doping ratio of the yttrium powder is 4wt%, and the average particle size of the yttrium powder is 100nm.

[0037] Step 2: Add grinding balls into the ball milling jar, the ratio of the mass of the balls to the mass of the powder is 30:1, add a sealing rubber ring on the ball milling jar, cover the lid of the ball milling jar, and close the air valve of the ball milling jar.

[0038] Step 3: Put the ball mill jar into the ball mill for high-energy ball milling, the ball mill speed is set to 600rpm, the ball milling time is 5h, and the size of the balls is 3mm. The grain size of the powder is refined by the high-energy ball milling method, and the yttrium powder and the tungsten powder are mixed uniformly at the same time.

[0039] Step 4: After the powder balls are milled, separate the powder and balls through a m...

Embodiment 3

[0045] Step 1: Under a nitrogen atmosphere in a glove box (nitrogen purity 99.999%), put the tungsten powder and the second-phase nanoparticle powder into a ball mill jar, the second-phase particle powder is a mixture of chromium powder and yttrium powder, which is doped The proportion is 8% by weight and the average particle size is 80nm.

[0046] Step 2: Add grinding balls in the ball milling jar, the ratio of the ball mass to the powder mass is 50:1, add a sealing rubber ring on the ball milling jar, cover the ball milling jar, and close the air valve of the ball milling jar.

[0047] Step 3: Put the ball mill jar into the ball mill for high-energy ball milling, the ball mill speed is set to 700rpm, the ball milling time is 10h, and the size of the balls is 3mm. The grain size of the powder is refined by high-energy ball milling, and at the same time, the second-phase nanoparticles and tungsten powder are mixed evenly.

[0048] Step 4: After the powder balls are milled, se...

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Abstract

The invention relates to the technical field of plasma-oriented materials in fusion reactors, and discloses a nanocrystalline tungsten alloy and a preparation method thereof. The tungsten powder and 1wt%-8wt% second-phase metal nanoparticle powder are doped and mixed, and subjected to high-energy ball milling. Afterwards, ultra-high voltage sintering is carried out, the sintering temperature is 1000°C-1200°C, the sintering time is 1-6h, the sintering pressure is 2-13GPa, the heating rate is 50-200°C / min, and the cooling rate is 50-200°C / min , the nanocrystalline tungsten alloy with ultra-high hardness and an average grain size of 9-14nm can be prepared. The technical advantage of the present invention is that it can effectively control the growth of tungsten crystal grains during the sintering process. One of the control functions is that the second phase particles are doped into nanoparticles; the other is the sintering method and the setting of sintering parameters. Using ultra-high voltage sintering technology, ultra-high voltage loading and low-temperature sintering can effectively inhibit the growth of grains, thus successfully preparing nanocrystalline tungsten-based materials.

Description

technical field [0001] The invention relates to the technical field of plasma-oriented materials in fusion reactors, in particular to a nanocrystalline tungsten alloy and a preparation method thereof. Background technique [0002] Tungsten is the most promising plasma-facing material in fusion reactors due to its high melting point, low thermal expansion coefficient, low sputter corrosion rate, high thermal conductivity, low hydrogen retention, and good strength at high temperatures, which make Tungsten can adapt to high-dose particle irradiation (such as neutron irradiation, deuterium, tritium, helium, etc.) and high heat flux environment in fusion reactors. [0003] Tungsten has many excellent properties, but as a plasma-oriented material, there are still many problems, mainly including: low-temperature brittleness, pure tungsten has a high ductile-brittle transition temperature, and in the temperature range of 200-400°C, it shows low-temperature brittleness ;The recrysta...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C22C27/04C22C1/05C22C1/04C22C1/10
CPCC22C1/045C22C1/05C22C27/04C22C2200/04
Inventor 付恩刚吴早明张俊
Owner PEKING UNIV