Effect of Scanning Method and Overlap Rate on the Microstructure and Properties of a Ni60-WC Composite Coating Laser Clad onto 45 Steel
J. Han, B-Y. Li and X-Q. Tian
In order to solve the problem of insufficient hardness and friction wear performance of Ni-based coatings under certain extreme working conditions, this paper designs experiments from a process perspective to study the effects of laser scanning method and overlap rate on the microstructure and properties of laser clad Ni60-WC composite coatings. Unlike previous studies, this study considers the comprehensive effects of laser scanning method and overlap rate on coating performance for specific laser clad layers, rather than just one of them. The results show that the performance of the coating after fusion is the best in the single line scanning mode and the overlap rate is within the range of 30 to 35%. The maximum hardness of the laser clad coating can reach 1216 HV, which is 1.08 to 1.43 times the 850 to 1150 HV hardness of the Ni-WC coating reported so far. The wear resistance of the laser clad coating has also been improved to some extent. The results confirm the phenomenon of interactive influence between scanning mode and overlap rate in the laser cladding process, which will provide a new 4knowledge for optimizing laser cladding in the future.
Keywords: Fibre laser, 45 steel, Ni60 alloy powder, Ni-WC, laser cladding, scanning method, overlap rate, microstructure, hardness, wear resistance