Laser and resistance joining of aluminum-graphite composite

This research investigates welding and brazing of Al-Gr composite using different joining techniques. Limited success is obtained for laser welding since laser degrades the mechanical properties at the weld due to defects in the resolidified aluminum matrix, delamination of graphite fibers, and formation of brittle aluminum carbide Al ₄C ₃. Brazing is the preferred technique since the low brazing temperature of filler material suppresses the formation of Al ₄C ₃ while minimizing shrinkage cavities in the joint. Microstructural study and shear testing confirms the success of joining Al-Gr by laser brazing and resistance brazing with Zn-Al filler.