Microstructure and wear resistance of laser clad Ti₂Ni₃Si/NiTi intermetallic coatings on titanium alloy

Wear resistant Ti₂Ni₃Si reinforced intermetallic coatings were fabricated on a substrate of titanium alloy BT9 by laser cladding using Ti-50Ni-10Si alloy powders as the precursor materials. Results indicate that the laser clad intermetallic coatings have a rapidly solidified homogeneous microstructure consisting of Ti₂Ni₃Si primary dendrites and Ti₂Ni₃Si/NiTi eutectic. Wear resistance of the laser clad Ti₂Ni₃Si reinforced intermetallic coatings was evaluated under dry sliding wear test conditions at room temperature. Because of the high hardness and strong covalent dominant atomic bonds of the Ti₂Ni₃Si primary dendrites with MgZn₂ type Laves crystal structure and the high yield strength and toughness of the eutectic, the Ti₂Ni₃Si/NiTi intermetallic coatings have excellent wear resistance under dry sliding wear test conditions.