孕镶金刚石硬质合金基底上沉积金刚石涂层工艺研究

Process of depositing diamond coating on diamond-impregnated cemented carbide

为提高金刚石涂层和基底的结合力,采用化学气相沉积方法在普通硬质合金和孕镶金刚石硬质合金基底上分别沉积金刚石涂层,并通过扫描电镜、拉曼光谱和压痕分析对比研究其结合性能。结果表明:在孕镶金刚石硬质合金基底上可以实现金刚石的同质与异质外延生长;在孕镶金刚石硬质合金基底上沉积的金刚石形核率高,晶形大小均匀,涂层表面平整;孕镶金刚石基底金刚石涂层的结合力优于硬质合金基底金刚石涂层膜基界面的结合力。在孕镶金刚石硬质合金基底上沉积金刚石膜可扩大金刚石涂层的应用范围。

To enhance the bonding strength between diamond coating and matrix, chemical vapor deposition was used to deposit diamond coatings on ordinary and diamond-impregnated cemented carbides, separately. SEM, Raman and indentation tests were used to analyze and compare the coatings. Results show that both homoepitaxial and heteroepitaxial growths of diamond coating could be found on the diamond-impregnated cemented carbide substrate, and that the coating deposited on diamond-impregnated cemented carbide substrate performs high diamond nucleation rate, uniform crystal size, and flat coating surface. It is also found that the bonding strength between diamond coating and diamond-impregnated cemented carbide is higher than that between coating and ordinary substrate, which will greatly expand the application of diamond coating.