| 摘要 |
PURPOSE: To provide a highly hard sintered compact for a tool having low specific resistance and capable of performing electrical-discharge machining even in the constituent region suitable for cutting of cast iron by including a large amount of non-conductive material comprising boron nitride of cubic system and aluminum oxide and/or aluminum nitride. CONSTITUTION: This highly hard sintered compact for tools contains >=85vol.% a non-conductive material comprising boron nitride of cubic system and aluminum oxide and/or aluminum nitride, and the remainders are a conductive material consisting mainly of titanium nitride and inevitable impurities. The boron nitride of cubic system is 30-80vol.% of the total sintered compact and specific resistance of the sintered compact is <=10Ω-cm. This compact has a low specific resistance and readily able to be electrically discharge machined in contrast to the conventional sintered compact highly containing non-conductive material, having high specific resistance, impossible of an electrically discharge machining, or practically unusable with generating exfoliation or fine defects even in a case of possible. |
