微型硬质合金钻头上金刚石涂层研究

Study of diamond coatings on cemented carbide-cobalt(WC-Co) micro-drills

WC-Co硬质合金钻头经过短时间酸腐蚀和微波等离子体硼氮化处理后,利用热丝CVD方法生长金刚石薄膜,并在电路板和玻璃板上进行了附着力测试。研究表明:钻头垂直于热丝放置,钻头端部为最高硬度的(111)面,有利于改善钻头切削加工性能;短时间酸腐蚀只去掉了钻头表面的钴,不降低表面硬度。同时酸腐蚀手段提高了表面粗糙度,避免了在随后的硼氮化处理时在WC表层形成低附着力的硼化物层,提高了金刚石薄膜附着力。在电路板及玻璃板上钻孔的测试结果表明,金刚石薄膜涂层钻头具有更高的寿命。

Followed by acid - etching process, the WC - Co micro - drills were boronitrided through microwave plasma process. The diamond films were deposited in hot - filament chemical vapor deposition （HFCVD） system and the adhesion were tested by drilling process on circuit and glass board. The results showed that, when the micro - drills were mounted in a vertical arrangement with the filament, the crystal face of the diamond on the tip of the micro - drills is （ 111 ）, which is beneficial to the enhancement of cutting quality of the drills. Short time acid etching process did not reduce superficial hardness because only a very small amount of cobalt was etched. But the surface roughness was heighten, which can avoid the growth of boride layer with low adhesion on WC surface during bomnitriding process and improve the adhesion of diamond films. The results which were tested by drilling on circuit and glass board showed that diamond films coated micro - drills have longer life - span.