Research of Gradient Wear-resisting Coating Produced by Laser Additive Manufacturing on High-pressure Pump Camshaft

2017 Journal of Mechanical Engineering  
To improve the wear resistance and operational reliability of high-pressure pump camshaft. The research of gradient wear-resisting coating produced by laser additive manufacturing on complex morphology high-pressure pump camshaft using the 5 kW CO 2 laser four-axis CNC machines and the co-axial powder feeding system. Based on the research of the gradient coating, the edge anti-collapse fixture and the movement control of cam, and realized the preparation of uniform high-hardness gradient
more » ... ess gradient coating without defects and the good protection of cam's edges. The macromorphology and microstructures are characterized by using laser microscope, SEM, XRD and microhardness tester. Comparison tests of service lives of the additive manufacturing camshafts and the cemented quenching camshafts are carried out on the high pressure pump test-bed. The results show that the primary phases of gradient coating are γ-Co solid solution, Co 3 B, M 23 C 6 and etc. The reinforcing phases are WC and W 2 C in transition layers and wear-resisting layer. The microstructures of gradient coating contains primary dendrites and interdendritic eutectics. The metallurgical bonding forms well between the gradient coating and the cam. Compared with the cemented quenching camshafts, the useful life of the additive manufacturing camshafts is increased by 65%.
doi:10.3901/jme.2017.06.080 fatcat:a7644645wne43mi2kuhxgn74xm