Abstract
This study describes a new discharge pulse pattern in order to make a hard TiC layer, which manufactured by an electrical discharge machining (EDM) with a semi-sintered electrode. In order to improve a hardness of the TiC layer, it needs to extend a diameter of crystallite on a crater formed by a single pulse discharge. To extend the diameter, we proposed a small discharge current (heating pulse) following to a former pulse pattern to increase a cystallite growth time. We investigated the time on the discharge crater with a thermal analysis and examined it experimentally. The results are as follows; The cystallite growth time is increased to 1.3 times by the heating pulse. The diameter of crystallite is 2.5 times as large as the former one and the TiC layer become harder by 15%.
