1School of Mechanical Engineering, Hefei University of Technology, Hefei 230009, China;2Key Laboratory
of Green Design and Manufacturing of Mechanical Industry, Hefei University of Technology, Hefei 230009, China
Abstract:Aiming at the problem of WC sinking in preparing Ni/WC composite coating, the coating was fabricated
by plasma transfer arc welding technology under the applied external magnetic field. The distribution of Ni/WC
coating plus WC particles under the applied magnetic field was investigated, and the microstructure and properties
of the coating were characterized by vickers durometer, SEM, OM and EDS. The results showed that WC was deposited
near the coating fusion line when no magnetic field was applied, while WC particles were concentrated in
the middle area of the coating when the magnetic field was applied, with a distance of 420 μm from the bottom of
the area to the coating fusion line. The hardness of the coating fluctuated with the applied magnetic field. The maximum
value of the hardness was 1400HV without external magnetic field, and it was 1450HV with external magnetic
field. In the experiment, WC particles almost did not melt and the particle morphology remained intact. The magnetic
field refines the coating structure, promotes the generation of hard phase and improves the hardness of the
coating. The external magnetic field solves the problem of WC subsidence and could be adjusted according to the
engineering requirements.