Method for improving content of hafnium in tantalum tungsten alloy

A technology of tantalum-tungsten alloy and content, which is applied in the field of refractory metal alloy preparation, can solve the problems of affecting the performance of the alloy, not being able to fill the molten pool, and poor density, so as to increase the melting speed, avoid a large amount of volatilization, and promote homogenization Effect

Active Publication Date: 2019-08-02
NORTHWEST INSTITUTE FOR NON-FERROUS METAL RESEARCH
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Under the current conditions of electric arc furnace melting equipment, if the electrode size matching the electric arc furnace crucible is used, the power of the electric arc furnace cannot be reached, and the alloy cannot be melted. If a smaller electrode is used, the crucible ratio will not be enough to fill the molten pool
Prepared by powder metallurgy, the alloy has high content of impurity elements and poor density, which is not conducive to subsequent processing. Forging and rolling are easy to crack and affect the performance of the alloy.
There is no grade of tantalum-tungsten alloy with hafnium added in my country, and there is no relevant research report

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0020] The preparation method of the present embodiment comprises the following steps:

[0021] Step 1. According to the design content of each element in the tantalum-tungsten alloy: Ta 94.5%, W 5%, Hf0.5%, select tantalum powder with a mass purity of 99.9% and a particle size of less than 60 meshes, with a mass purity of 99.9% and a particle size of Prepare alloy powder with tungsten powder less than 150 mesh and hafnium powder with a mass purity of 99.9% and particle size less than 120 mesh, and then use a V-type mixer to mix the alloy powder for 24 hours to obtain a mixed powder;

[0022] Step 2, using a 600T press to press the mixed powder obtained in step 1 into a billet of 16mm × 16mm × 400mm (width × height × length);

[0023] Step 3. Carry out vacuum high-temperature sintering on the billet obtained in step 2 to obtain a sintered billet; the vacuum high-temperature sintering system is: the degree of vacuum does not exceed 5.0×10 -1 Pa, raise the temperature to 1500°C...

Embodiment 2

[0027] The preparation method of the present embodiment comprises the following steps:

[0028] Step 1. According to the design content of each element in the tantalum-tungsten alloy: Ta 84%, W 6%, Hf 10%, select tantalum powder with a mass purity of 99.9% and a particle size of less than 240 mesh, with a mass purity of 99.9% and a particle size of less than 150-mesh tungsten powder and hafnium powder with a mass purity of 99.9% and a particle size of less than 120 mesh are used to prepare alloy powder, and then the alloy powder is mixed for 24 hours with a V-shaped mixer to obtain a mixed powder;

[0029] Step 2, using a 600T press to press the mixed powder obtained in step 1 into a billet of 16mm × 16mm × 400mm (width × height × length);

[0030] Step 3. Carry out vacuum high-temperature sintering on the billet obtained in step 2 to obtain a sintered billet; the vacuum high-temperature sintering system is: the degree of vacuum does not exceed 5.0×10 -1 Pa, heat up to 1500°C...

Embodiment 3

[0034] The preparation method of the present embodiment comprises the following steps:

[0035] Step 1. According to the design content of each element in the tantalum-tungsten alloy: Ta 90.5%, W 8%, Hf 1.5%, select tantalum powder with a mass purity of 99.99% and a particle size of less than 60 mesh, with a mass purity of 99.99% and a particle size of less than 150-mesh tungsten powder and hafnium powder with a mass purity of 99.99% and a particle size of less than 120 mesh to prepare alloy powder, and then use a V-shaped mixer to mix the alloy powder for 24 hours to obtain a mixed powder;

[0036] Step 2, using a 600T press to press the mixed powder obtained in step 1 into a billet of 16mm × 16mm × 400mm (width × height × length);

[0037] Step 3. Carry out vacuum high-temperature sintering on the billet obtained in step 2 to obtain a sintered billet; the vacuum high-temperature sintering system is: the degree of vacuum does not exceed 5.0×10 -1 Pa, heat up to 1500°C within...

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Abstract

The invention discloses a method for improving the content of hafnium in tantalum tungsten alloy. The method comprises the following steps of I, uniformly mixing a tantalum powder, a tungsten powder and a hafnium powder according to the designed content to obtain mixed powder; 2, pressing the mixed powder into a blank strip; 3, carrying out vacuum high-temperature sintering on the blank strip, soas to obtain a sintered blank strip; 4, carrying out two-time vacuum electron beam smelting on the sintered blank strip to obtain the tantalum tungsten alloy. According to the method, the raw materialpowder is pre-alloyed by virtue of high-temperature vacuum sintering, the argon protection is timely carried out in the cooling process, the volatilization of hafnium is effectively reduced, different smelting speeds are adopted in the two-time rapid vacuum electron beam smelting process, so that the hafnium element is prevented from being drawn out in a large amount, the homogenization of the tantalum tungsten alloy is promoted, so that a large amount of volatilization of hafnium elements is further avoided, and the mass content of hafnium in the final tantalum tungsten alloy is more than 80% of the design content.

Description

technical field [0001] The invention belongs to the technical field of preparation of refractory metal alloys, and in particular relates to a method for increasing the content of hafnium in tantalum-tungsten alloys. Background technique [0002] Tantalum alloys have the advantages of high melting point, high strength, good room temperature plasticity, corrosion resistance and easy processing and forming, and are widely used in the fields of chemical industry, aviation, aerospace and atomic energy industries. At present, the mature tantalum alloys in my country mainly include Ta2.5W, Ta10W, and Ta12W, but these series of alloys all have the problem of not being resistant to oxidation. By adding a certain amount of Hf element, the solubility of oxygen in the alloy can be effectively reduced, and the corrosion resistance of the alloy to alkali metals such as potassium, sodium, lithium, cesium, and mercury can be improved. After adding Hf element, the high-temperature performan...

Claims

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Application Information

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IPC IPC(8): C22C27/02C22C1/04C22C1/02C22B9/22C22B9/04
CPCC22B9/04C22B9/22C22C1/02C22C1/045C22C27/02
Inventor 白润刘辉王晖李来平王峰蔡小梅夏明星薛建嵘
Owner NORTHWEST INSTITUTE FOR NON-FERROUS METAL RESEARCH
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