Ceramic layers formed on metals by reactive plasma processing

Thick layers of ceramics mainly composed of TaC, ZrO 2 and Ti 2AlN 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, ZrO 2 and Ti 2AlN were estimated to be approximately 3000, 1300 and 3500 Hv[kg/mm 2], 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.