Research progress on influence factor of transient liquid phase diffusion bonding of nickel-based single crystal superalloy

Influence of interlayer alloy,welding parameter and crystal misorientation angle of base metal on the TLP joint of nikel-base single crystal superalloy is discussed in detail. Normally,the main alloying elements of interlayer alloy are similar to the base metal and B is selected as melting-point depressant. Owing to composition uniformity and fast diffusion rate in comparison to mealy interlayer alloy,morphous strip of interlayer alloy is beneficial to improve performance of the joint,which is the optimised state of interlayer alloy. Welding parameter,such as welding temperature,holding time,welding pressure and postweld heat treatment,should be selected rationally according to the performation requirement of base metal and joint,as well as processing procedure. To avoid the deleterious effect of stray grain on the mechanical properties of joint,crystal misorientation angle of welding samples should be minimized or eliminated.