Transformation of titanium surface to TiC- or TiN-ceramics by reactive plasma processing

The sub-surfaces of pure Ti-plates were transformed to the cermets TiC and TiN by plasma processing. The thickness and hardness of the modified layers increased with the processing temperature, distinguishably, over 1000°C. The maximum values of Vickerʹs hardness and thickness of the modified layers of TiC and TiN processed for 5 and 2 h at processing temperatures of 1400 and 1300°C, respectively, were approximately 5000 kg·mm−2/40 μm and 5400 kg·mm−2/55 μm. A distribution profile of carbon at the interface region of TiC characterized by electron probe micro-analysis (EPMA) suggested that the modified layer of ceramics was regarded as a kind of functionally graded material.