Interface Microstructural Characterization of Titanium to Stainless Steel Dissimilar Friction Welds

摘要

Microstructural evolution and characterization of interfacial reactions during friction welding of commercially pure titanium and 304 stainless steel using a Ni interlayer were investigated. A thin interdiffusion solid solution layer and a discontinuous layer of Ti-Ni-type intermetallic compounds formed adjacent to the titanium-nickel interlayer interface. The weld interface of titanium to interlayer has formed with three types of layers which are consisting of TiNi, TiNi_3 and Ti_2Ni, intermetallic compounds. The interdiffusion path for the reaction of intermetallic compounds was established at this interface. Electron probe microscope analysis (EPMA) revealed the formation of Ti-Ni-based intermetallic compounds and confirmed the absence of Fe-Ti-type brittle intermetallic compounds. Tensile tests indicated that the failure in the joints occurred by formation and propagation of the crack mostly along the titanium-nickel interlayer interface, through the Ti-Ni-type intermetallic layers.