In situ laser-assisted diamond turning of Ni-P alloy coating on mold core surface

Due to the instability of amorphous alloys, the Ni-P alloy coating on the surface of injection mold cores will crystallize after a long period in a high-temperature and high-pressure production environment. The crystallized alloy has higher hardness, poorer ductility, and poorer machinability, making it difficult to repair by single-point diamond turning. This paper presents the results of heat treatment experiments simulating a production environment to obtain the relationship between heat treatment temperature and surface hardness after crystallization. Using the high transmittance of diamond, laser in-situ assisted diamond turning can improve the surface quality and eliminate machining defects, and analyze the influence of process parameters on the surface roughness to determine the optimal machining parameters. The experimental results show that using laser in-situ assisted diamond turning can improve surface quality, extend tool life, and improve accuracy. The final measured face accuracy confirms that the laser-assisted in-situ turned cores are suitable for routine injection molding production.