Investigation Into Microstructure And Properties Of Ni/Co-based Alloys Cladding Layers Reinforced With Wc Particles

H13 steel is commonly used for the production of stirrer tool materials for welding low-melting alloy materials such as aluminum,magnesium and copper by friction stir welding?FSW?due to its red hardness,wear resistance and creep resistance.However,in the process of welding ferrous metal by FSW technology,the stirring head is subjected to wear and high temperature oxidation,resulting in damage and failure.Therefore,it is necessary to study the surface modification properties of H13 steel,which provides a theoretical basis for the FSW technology in the field of connecting ferrous metals.This project takes H13 steel as the matrix,and uses laser cladding technology to obtain metal-based ceramic cladding layer,This project takes H13 steel as the matrix,and uses laser cladding technology to obtain metal-based ceramic cladding layer.Based on the study of surface forming quality,macro hardness and dilution rate,the optimum cladding process parameters of Ni-based WC cladding layer are determined as follows:laser power is 1200W,scanning speed is 4mm/s,preset powder thickness is 1.0mm.The optimum cladding process parameters of the Co/WC cladding layer are determined as follows:laser power is 1500W,scanning speed is 4mm/s,and preset powder thickness is 1.0mm.The Ni60A cladding layer is mainly composed of?-Ni solid solution,M₇C₃ and Fe₃C carbide.As the amount of WC added increases,the network eutectic structure disappears in the cladding layer,the microstructure is refined,and carbides such as M₂₃C₆,W₂C,and WC appear in the cladding layer.When the mass fraction of WC exceeds 20%,the phase composition of the cladding layer does not change.The St6cladding layer is mainly composed of?-Co solid solution,M₂₃C₆ and M₇C₃ carbide.With the addition of WC particles,the cell structure in the cladding layer decreases,the petal-like structure increases,and W₂C and WC carbides appear.Compared with the Ni60A and St6 cladding layers,the hardness of the composite cladding layer formed by the addition of WC particles is significantly improved.The wear test results show that the main wear mechanisms of Ni60A and St6 cladding layers are adhesive wear and plastic deformation,and the wear resistance is the worst.With the increase of the quality of WC particles,the wear resistance of the cladding layer becomes better.The wear resistance of St6-30%WC cladding layer is the best,secondly is the Ni60A-20%WC cladding layer,the main wear mechanism is abrasive wear.High temperature oxidation test shows,the high temperature oxidation resistance of St6-30%WC cladding layer is the best,secondly is the Ni60A-20%WC cladding layer...