Abstract
Tiebar-cut punch is a cutting tool which is attached to a mold for cutting lead frame and resin. For this tool, high wear resistant hard materials(especially cemented carbide)are widely used. It is generally known that the life-time of tiebar-cut punch depends on the wear resistance to resin, on the other hand, high toughness is required. However it is difficult for cemented carbide to increase both properties because there is a trade-off relation between wear resistance and transverse rupture strength. To overcome this problem and to improve the property of cemented carbide, we developed a new functionally graded material of cemented carbide (FGM) which coated high wear resistant cemented carbide on tough cemented carbide with pulse current pressure sintering system. We applied this FGM to tiebar-cut punch and evaluated it by cutting test. Compared with a conventional tiebar-cut punch, the FGM tiebar-cut punch revealed higher wear resistance.
