Research on interfacial layer of laser-welded aluminum to titanium

Formation mechanism of intermetallic compounds (IMCs) and its relation with strength reduction for laser-welded aluminum to titanium were investigated in this study. It was found that the interfacial layer is composed of alpha-Ti, TiAl3, Ti2Al, TiAl, Ti3Al and alpha-Al. TiAl3 is precipitated from liquid Al and formed in an orientation relationship with alpha-Al. Strength reduction of Ti-Al joints with increment of IMCs are due to the weak regions including lattice distortion at interface between TiAl/Ti3Al and stacking fault in TiAl3. The results intend to explore the factors determining joint strength and contributed to the welding process improvement.