Electrical discharge process for rapid oxycarburisation of titanium in air

• DOI: 10.1179/1743284714y.0000000666
• Publication Date: 2014-09-22T13:54:43Z
• Authors: Y. J. Jo; Y. H. Jo; J. G. Seong; Y. H. Kim; S. Y. Chang; W. H. Lee
• Keywords: 02 engineering and technology; 0210 nano-technology

A single pulse of 2·0–3·5 kJ of input energy from a 450 μF capacitor was applied to a Ti rod. The electrical discharge process can produce rapid temperature increases of Ti from 569 to 2398°C in times as short as 159 μs, depending on the input energy. With an input energy greater than 2·5 kJ, a β→α allotropic transformation occurred, showing a typical serrated morphology. At the same time, the original surface of Ti rod with TiO2 was modified into the form of primarily titanium oxycarbide. A much higher value of hardness that was observed at the edge of the cross-section was thus attributed to oxygen- and carbon-induced solid solution hardening during the electrical discharge process.