Friction spot brazing of stainless steel to titanium (grade 1) using aluminum foil

Abstract

This paper demonstrates a simple and effective technique for friction spot brazing of stainless steel (st37) to titanium (grade 1). We use aluminum foil as a filler that is placed between the base metals. We evaluate the joints when using different rotational speeds: 1800, 2000, 2200, 2400, 2600, and 2800 RPM. We characterize the joint using scanning electron microscopy, optical microscopy, energy dispersive x-ray analysis, the microhardness of cross-sections, and fractography. We found that the strongest tensile strength joint (6 kN) come from friction spot brazing at 2000 RPM. The joint interface of the 2000 RPM sample contains intermetallic compounds such as FeTi, Fe3Al, FeAl2, and Ti3Al, which increases the tensile strength.