Optimization Of Process Parameters And Mechanical Properties Of The Nickel-based Coating On The Glass Mold Through Plasma Transferred Arc

Rapid development of glass industry requires high-quality wear-resistance coating on the copper glass mold cavity,especially the surface of molding mold cavity.Owing to high wear-resistance,high temperature oxidation resistance and corrosive resistance associated with NiCrBSi alloy,it is expected to be a promising candidate for wear-resistant coating material on lots of components.Meanwhile,Because of the low dilution ratio and excellent metallurgical bonding with substrate,plasma transfer arc welding?PTAW?has been widely employed to deposit Ni-based coating on the surface of copper glass mold cavity.In this paper,PTAW were used to deposit NiCrBSi self-fluxing alloy powder on a cast copper glass mold cavity surface.Optimization of the processing parameters was firstly proposed,and microstructure and mechanical properties of the as-deposited coating obtained through PTAW were analyzed and evaluated using optical microscope?OM?,microhardness tester,X-ray diffraction?XRD?,scanning electron microscope?SEM?with Energy Disperse Spectroscopy?EDS?and the ball-disc wear tester.The results show that the defect-free nickel-base alloy coating with a thickness of3-5mm and good metallurgical bonding to copper substrate was achieved with optimized processing parameters.Phase constituents of Ni-based coating mainly consists of y-Ni dendrite solid solution phase and Cr₇C₃?SiNi₃?FeNi₃ compound,and microstructure consists of fine equiaxed grains at the bottom,dendritic zone of middle layer and fine equiaxed grains on the top.The average microhardness of coating layer reaches to 335HV0.3,which is increased by 45.7%in comparison with copper alloy base,and the fusion zone width of coating layer is about 0.5mm.The wear rate of the Ni-based coating is decreased from 0.0710×10^-6mm³N^-1m^-1 of copper structure to 0.010?0.0146×10^-6 mm³N^-1m^-1 at an applied loading of 5N,and it is further applied load of 10N reduced to 0.0239?0.0288×10^-6mm³N^-1m^-1 at a applied load of 10N.On the basis of above analysis,optimization of plasma welding process of nickel-based alloy powders on the surface of copper glass mold was achieved to enhance wear resistance,subsequently improving the quality and service longevity of glass mold,and satisfying the requirements for demand and production and design.