A SPS diffusion welding method for TZM and WRe dissimilar refractory alloys was proposed. The joints of TZM and WRe dissimilar refractory alloys were obtained by solid diffusion welding of TZM and WRe alloys using SPS technology. The welding method of the invention can ensure that the base metal does not recrystallize, and the TZM and WRe dissimilar refractory alloy welding parts with high strength and good shape can be obtained, and the joint room temperature shear strength can reach 234MPa.
TZM alloy is formed by adding alloying elements (such as titanium and zirconium) with molybdenum as matrix, and has high recrystallization temperature, excellent high temperature mechanical properties and good corrosion resistance. It has been widely used in aviation, aerospace, nuclear energy and other fields, such as: using its excellent high temperature mechanical properties, It can be used for heat dissipation panel of spacecraft, nozzle of rocket engine, valve body bearing high temperature in torpedo engine, etc. Using its high melting point, can be used for seamless stainless steel perforated head, high temperature furnace wall and heat insulation screen of hot isostatic press and other high temperature structural materials; TZM alloy is also widely used in electronic and electrical industry, such as electron tube cathode, gate, high voltage rectifier semiconductor film integrated circuit, etc. In addition, TZM alloy is also widely used in nuclear energy equipment, such as radiation cover, support frame, heat exchanger, rail and so on.
The effective connection between TZM and WRe heterofusible alloys is the key to expand the application of refractory alloys in aerospace, nuclear energy, weapons and other fields. However, due to the great differences in physical and chemical properties of the two materials (such as large differences in melting points), it is very difficult to connect the two materials. At present, fusion welding, brazing welding, solid phase diffusion bonding and instantaneous liquid phase bonding are mainly used to realize the bonding of superalloys. However, these methods have many shortcomings: it is difficult to make joints with high bonding strength; The cleanliness of the surface of the metal parts and the vacuum of the equipment are very high; High temperature and long holding time are required for solid phase diffusion connection and transient liquid phase connection, resulting in time-consuming and energy consumption of connection between the two. Fusion welding is prone to crack; Although the brazing temperature is low, it is difficult to make joints that can be used at high temperature because of the low melting point of the solder.
In view of the shortcomings of the existing refractory alloy, especially the connection technology of TZM alloy and WRe alloy, the purpose of the invention is to apply SPS technology to the solid diffusion connection of refractory alloy and provide a fast and efficient welding method of TZM and WRe dissimilar refractory alloy. By adding vanadium box as the intermediate transition layer, In order to reduce the welding temperature, avoid the recrystallization of the base metal, and form a complete solid solution through atomic mutual diffusion in the weld, and then improve the mechanical properties of the welded joint.
