Influence of using electroless Ni-P coated WC-Co powder on laser cladding of stainless steel

In this investigation, nickel (Ni)-coated WC-12Co powder was produced using an electroless nickel‑phosphorus (Ni-P) plating process and then used as a feedstock material for laser cladding of AISI 321 stainless steel substrate. The correlations that exist between key operational parameters of the process (i.e., laser power, scanning speed, powder feeding rate) and geometrical characteristics for single claddings (i.e. height, width, dilution, and wetting angle) were predicted and analyzed by regression analysis method (RA). A processing window for laser cladding of Ni-coated WC-12Co powder on AISI 321 stainless steel was developed based on an empirical-statistical model and the processing window was compared with that for laser cladding of commercial WC-12Co powder without nickel coating. Furthermore, the influence of using Ni-coated WC-12Co powder on the microstructure and microhardness was investigated and compared with those of laser cladded commercial WC-12Co claddings. The results showed that the use of Ni-coated WC-12Co powder could significantly reduce the porosity percentage and lead to high-quality claddings.