Studies on joining of Ti 6Al 4V with inconel 718 and stainless steel 304l by diffusion bonding and friction welding

Abstract

Titanium alloys are joined to nickel alloys for applications in newlineaerospace engines. Titanium alloys are joined to stainless steels for nuclear newlineapplications. Conventional fusion welding is not a feasible technique to join newlinethese kinds of dissimilar joints due to the formation of chemical, mechanical newlineand structural heterogeneities. Solid state joining is a suitable alternate to newlineovercome the difficulties. Diffusion bonding gives a sound bond without any macroscopic newlinedeformation because it involves only inter-atomic diffusion of atoms across newlinethe interface between the two metals being bonded. Energy required for the newlinemovement of atoms depends on the applied stress and temperature. One newlineimportant advantage of the diffusion bonding is that the individual newlinecharacteristics of the base materials are retained after bonding, except newlineprobably at the interface. Friction welding is a solid state welding process that produces a newlineweld under a compressive contact stress between the work pieces while newlinerotating or moving relative to one another to produce heat and plastically newlinedisplace material from the faying surfaces. When a suitable high temperature has been reached, rotational motion ceases, additional stress is applied and newlinecoalescence occurs. The short duration is the main advantage of friction newlinewelding process. newlineThe main purpose of the present study is to investigate and newlinecompare the characteristics of dissimilar joining of Ti-6Al-4V with Inconel newline718 and Ti-6Al-4V with SS 304L using diffusion bonding and friction newlinewelding processes. The investigation is done by making dissimilar joints of newlinethe two combinations of materials by the two solid state welding processes, newlinefor varied combination of the key parameters of the processes. newline