The effect of irradiation parameters of high-intensity pulsed ion beam on tribology performance of YWN8 cemented carbides

In order to investigate the effect of processing parameters of high-intensity pulsed ion beam (HIPIB) on the performance of WC-Ni which contained 8% Ni (YWN8), four groups of parameters, with current densities of 100, 200 and 300 A/cm2 with one to five shots, were selected to irradiate the samples. The microstructure, morphology and topography of YWN8 cemented carbides before and after irradiated were given. It revealed that the polishing scratches and some mechanical debris formed in the grinding process on the YWN8 surface could be well cleared under appropriate irradiation parameters in which the surface absorption energy was about 0.11 J (the medium ion current density of 300 A/cm2 with 1 shot and of 100 A/cm2 up to 5 shots). The friction and wear performance test done by SRV indicated that with these processing parameters, the tribological performance of irradiated YWN8 and carbon graphite impregnated with antimony was obviously improved where the friction coefficient reduced from 0.1 to 0.06–0.07. The results of X-ray diffraction (XRD) showed that graphite emerged on the surface due to the implantation of C+ and decomposition of WC under high temperature during irradiation improving self-lubricity of YWN8. In addition, adhesive wear of the carbon graphite was distinctly moderated while rubbed with irradiated YWN8 because the polishing scratches on the surface have been well removed after irradiation.

► The WC-Ni samples were irradiated by HIPIB with different parameters. ► The surface properties of YWN8 will be affected by the surface absorption energy. ► The surface became smoother after irradiation with proper parameter. ► A graphite phase found on the irradiated YWN8 surface will improve lubricity. ► Irradiated YWN8 shows superior tribological performance rubbed with carbon graphite.