Low temperature diffusion welding method of tungsten alloy and tantalum alloy, the steps of the method include: (1) workpiece surface cleaning steps: tungsten alloy, tantalum alloy processing to the specified size, remove them and the middle layer - nickel foil to be welded surface oxidation layer; (2) Workpiece assembly steps: place the middle layer - nickel foil between tungsten alloy and tantalum alloy to construct the welder workpiece; (3) Vacuum diffusion welding steps: put the welder parts into the vacuum diffusion welding furnace, heat and keep warm. When the heat preservation begins, apply axial pressure on the welder parts. After the heat preservation, remove the pressure and cool with the furnace. The invention can overcome the problem that the existing welding technology cannot realize high-quality diffusion welding of tungsten alloy and tantalum alloy at low temperature, especially suitable for reliable and precise diffusion welding between tungsten alloy and tantalum alloy at low temperature, and the tungsten and tantalum welding body prepared can be used in dynamic high pressure physics and nuclear fusion and other research fields.
High-density tungsten alloy has a series of excellent properties such as high density, high strength, good ductility, good machining performance, low linear expansion coefficient, high thermal conductivity, good oxidation and corrosion resistance, good weldability and so on. These excellent properties make it widely used in high-tech fields, military and civil industries, such as balance weight components, conventional components, ray shielding materials, etc. Among them, high-density tungsten alloy has good rigidity and easy shape maintenance, which is an ideal nuclear fuel storage and radiation shielding material. At the same time, W-Ni-Fe alloy has a series of excellent properties, such as high melting point, good impact toughness, high plasticity and low yield strength, can be used to manufacture a thin-walled large chain shell, as a functional composite material used in atomic energy explosion, to ensure the normal operation of the instrument.
Defects in direct welding joints of tungsten alloy and tantalum alloy lead to low corrosion resistance and reduced service life of materials. The welding strength was improved after the welding temperature was further improved, but the fracture toughness of the material was reduced due to the recrystallization and grain coarsening of W and Ta. The decrease of welding temperature will lead to the decrease of welding strength; At the same time, Ta begins to oxidize when heated to 200°C, and rapidly oxidizes above 500°C, and has the characteristics of absorbing hydrogen, oxygen and nitrogen. A small amount of gaseous impurities will have a strong impact on its organizational structure and mechanical properties.
A low temperature diffusion welding method of tungsten alloy and tantalum alloy is provided to overcome the deficiency of direct welding of tungsten alloy and tantalum alloy in the existing technology and realize high strength connection between tungsten alloy and tantalum alloy at low temperature, especially suitable for low temperature diffusion welding of tungsten alloy thin plate and tantalum alloy thin plate.
