Consideration of the criteria for successful deposition in cermet kinetic spraying using WC-17Co powder

There have been several studies related to the cermet kinetic spraying, despite its difficulty of proper deposition. However, there is no specific deposition criteria for kinetic spraying of cermet due to the unclearness of deposition mechanism in cermet kinetic spraying. Thus, the criteria of the successful cermet kinetic spraying was considered using commercial WC-17Co powder by correlating the numerical and experimental results. Firstly, alteration in the deposition behavior of WC-17Co powder according to the change of impact velocity was investigated and classified from the results of single particle impact tests. Afterward, by correlating the experimental results with the thermomechanical response of the supersonic impacted WC-17Co particle, the deposition criteria of cermet kinetic spraying was considered. As a result, two criteria were derived: i) enough to cause a plastic deformation of metal part to such an extent that temperature rise to ~ Tm occurred at the interface and the inner particle region near the interface, ii) but not enough to make Er overly dominant than Ep. When the practical kinetic spraying of WC-17Co powder was conducted after the choice of process condition compatible to such criteria, it was confirmed that the two deposition criteria mentioned above was fairly effective.