Laser deposition of refractory MO- NI alloys

Mo-Ni alloys have wide applications in the nuclear and aeronautical industries. It is of great technological interests to investigate laser deposition Mo-Ni alloy for further laser direct manufacturing near net shape Mo-Ni components. The research work contains the characteristics study of overlap multi-pass laser cladding of Mo-Ni alloys, the microstructure, hardness and mechanical property analysis. Refractory Mo-Ni alloys Mo48Ni52 and Mo70Ni30 were deposited by laser via coaxial feeding of pure powder blend of Mo and Ni. The Mo48Ni52 alloy is composed of Ni solid solution NiMo phase Ni₃Mo phase and Ni₄Mo phase while the 70Ni30 alloy consists of Mo solid solution and NiMo phases. The average hardness of Mo48Ni52 and Mo70Ni30 alloys are respectively HRA77.6 and HRA75.2.Cracking occurs in multi-layer laser deposition of both Mo48Ni52 and Mo70Ni30 alloys. High-temperature compression tests were performed at 900°C. The highest practical force of Mo48Ni52 is 7605N, the elastic ratio is 11816.74N/mm² and brittleness compression strength is 608N/mm². The highest practical force of Mo70Ni30 is 12417N, the elastic ratio is 10296.27N/mm² and brittleness compression strength is 990N/mm².