Tungsten and low-activation stainless steel nano-gradient composite connection method

Abstract

The invention relates to a tungsten and low-activation stainless steel nano-gradient composite-diffusion connection method. According to the method, firstly, a nano composite W-Fe gradient transition layer of a two-layer structure or a three-layer structure is designed, nano composite W-Fe powder is prepared through a collosol-spray drying-thermal recovery or high energy ball milling method, and the granularity of the powder of different ingredients and sintering activity are controlled, so that the purpose that the powder of different ingredients is sintered to be close to fully dense at the same temperature is achieved; then, the W-Fe which is good in interlayer combination and close to the fully dense gradient is prepared through layered powder laying-pressing forming-high-temperature sintering forming; and finally, a W-Fe gradient transition layer high-tungsten alloy end and a W-Fe gradient transition layer low-tungsten alloy end are subjected to diffusion connection with tungsten and stainless steel in sequence correspondingly, and a W / gradient W-Fe / stainless steel connection sample piece is obtained. By means of the tungsten and low-activation stainless steel nano-gradient composite-diffusion connection method, the tungsten and stainless steel connection interface forms dense metallurgical bonding at a low temperature, connection strength is above 200 MPa, and interface stress concentration and stainless steel base material performance deterioration caused by direct connection or brazing are avoided.

Description

technical field [0001] The invention relates to a connection method between dissimilar metals in the technical field of powder metallurgy, in particular to a nano-gradient composite connection method of tungsten and stainless steel. Background technique [0002] Tungsten (W) has high melting point, high hardness, good high temperature strength, thermal conductivity, electrical conductivity, low thermal expansion coefficient, low sputtering when interacting with plasma, no chemical reaction with H, H + It is a very important high-temperature structural material and functional material with low retention characteristics, and has important applications in nuclear energy, aerospace, electronics and other fields. Stainless steel is an important heat sink structural material due to its good thermal conductivity and mechanical properties. For example, in nuclear fusion, W is connected with stainless steel to form a part facing the plasma, which is used as the most critical first w...

AI Technical Summary

Problems solved by technology

This method is used for connection to realize the performance gradient transition from tungsten to stainless steel. The connection interface forms a dense metallurgical bond, and the connection strength is above 200MPa, which solves the problems of interface thermal stress adaptation and high-strength bonding at the interface. It is expected to become a future fusion reactor. New technology and method for the preparation of plasma fusion materials and component materials