Surface modification of refractory alloys with high-power pulsed ion-beam treatment and arc-pulsed ion implantation

Abstract

High-power pulsed ion beam (HPPIB) treatment and arc-pulsed ion implantation (APII) were combined consecutively to be the improvement of service properties of high temperature refractory alloys. The influence of this combined processing on the physical and chemical state of refractory alloy surface layers was studied. It is shown that it is possible to combine the positive effects of each technology in order to obtain an ideal smooth surface (without craters, Ra =0.06-0.10 pm) and to increase the alloyed surface layer thickness due to irradiation-enhanced diffusion. Consequently, the positive effect of this combined treatment on the fatigue strength, salt corrosion resistance, and oxidation resistance is connected with the following processes: smoothing of a surface microrelief; high-speed-solidification; surface alloying; structure stabilization during a post-process vacuum annealing.