Tantalum tungsten alloy foil preparation method, including the following steps: tungsten powder and tantalum powder mixed powder, among them, the mass percentage of tungsten powder is 10.0 11.5%, the tungsten powder includes particle size of 1 3μm, 3 5μm, 5 7μm tungsten powder; The mixed powder was formed by cold pressing and vacuum sintering to get sintered billet. Then vacuum vertical melting was carried out to obtain vertical melting billet. The vertical billet was coated with stainless steel in an argon chamber. The vertical melting ingot after the treatment in step 4 is forged at the preset temperature. The stainless steel coating on the surface of the billet was removed, and multi-pass cold rolling deformation and annealing treatment were carried out alternately. When the billet was cold rolling deformation to the thickness of 0.01mm, the surface cleaning was carried out. Vacuum annealing and cold rolling with tension are used to obtain foil with thickness less than 7μm. Winding tantalum-tungsten alloy foil onto cast iron foil for vacuum annealing treatment, and naturally cooling to obtain the desired tantalum-tungsten alloy foil. The tantalum tungsten alloy foil has high tungsten content and thin thickness.
Tantalum-tungsten (Ta-W) alloy is widely used in aerospace, national defense, chemical industry and nuclear industry due to its advantages of high density, high melting point, high elastic modulus, high ductility, good processing performance, high temperature strength, corrosion resistance, weldability and low plastic-brittle transition temperature. Tungsten can be added to tantalum to form solid solution alloy, which can strengthen and refine grain. With the increase of tungsten content, the properties of tantalum-tungsten alloy can be improved obviously at room temperature and high temperature.
With the development of electric vacuum, electronic and electrical, nuclear energy and other industries, tantalum tungsten alloy foil with high strength, ultra-thin and high tungsten content has become the required materials for magnetron cathode, electron tube cathode, grid and high voltage rectifier element. Among them, one of the important uses of tantalum tungsten alloy foil with high tungsten content is to make a magnetron primary cathode. The strength and thickness of tantalum tungsten alloy foil directly affect the emission efficiency, microwave tube output power and working stability of the cathode under the same acceleration voltage.
