Microstructure of laser clad TiC/NiAl-Ni₃(Al, Ti, C) wear-resistant intermetallic matrix composite coatings

TiC-reinforced NiAl-Ni₃(Al, Ti, C) intermetallic matrix composite coatings are fabricated by laser cladding with powder blends of Ni-Al-Ti-C on substrate of electrolyzed nickel plate. The microstructure consists of TiC particles, primary NiAl dendrites and the interdendritic Ni₃(Al, Ti, C) phase; the composite coatings can be obtained with the features of high-quality metallurgical bonding with the substrate. The volume fraction of Ni₃(Al, Ti, C) phase increases with increasing laser scanning speed, but that of dendritic NiAl intermetallic alloy shows a decreasing tendency. Furthermore, the growth morphology of reinforcements changes from octahedron to developed dendrite with laser scanning speed.