微波等离子体条件下硬质合金刀片中钴的扩散规律对金刚石涂层的影响

Diffusion of Co in Hard Alloy Cutting Tools Under the Condition of Microwave Plasma CVD and its Influence on Diamond Coatings

利用化学脱钴处理后的硬质合金刀片在微波等离子体条件下沉积金刚石薄膜,用电子能谱仪(EDS)检测发现经化学酸蚀处理后的硬质合金刀片表面的钴含量基本在0.3%左右,对于金刚石膜的形核及生长几乎没有大的影响,膜层致密、晶型良好;但是在长时间的高温沉积过程中,钴逐渐向表面扩散,如900℃条件下10h后刀片表面钴含量可达2.02%,可能对金刚石薄膜与基体之间的附着产生很大的影响,导致金刚石薄膜刀具使用使命的降低。

Diamond films were deposited on hard alloy with microwave plasma CVD method. They were etched with acid to remove cobalt (Co). The diffusion of Co in the hard alloy cutting tools under high temperature was studied quantitatively. The adhesion between the substrate and diamond film can be improved by controlling surface Co content. EDS results show that the Co content on the substrate surface is about 0.3%. It affects less on the nucleation and growth of diamond film. However, in a long term deposition under high temperature, Co gradually diffuses to the surface of substrate. The Co content of the substrate surface can rise up to 2.02% under 900°C in 10 hours. A high Co content may influence the adhesion between the substrate and the diamond films and result in a short life of diamond film cutting tools.