Ceramic layers formed on metals by reactive plasma processing

Thick layers of ceramics mainly composed of TaC, ZrO2 and Ti2AlN were successfully synthesized on the surfaces of Ta, Zr and TiAl by means of novel plasma dry processing with or without 20 MeV-electron beam irradiation as the pretreatment. The thickness of these ceramic layers reached 10–100 μm under appropriate process conditions. Vickers hardness of the layers including TaC, ZrO2 and Ti2AlN were estimated to be approximately 3000, 1300 and 3500 Hv[kg/mm2], respectively. The cross-sectional profiles of constituent elements graded gradually in the modified surface regions, suggesting that these ceramics must have some properties of functionally graded materials.