真空渗硼预处理在CVD金刚石-硬质合金涂层工具中的应用

Application of Vacuum Boronizing Process in CVD Diamond Coated Cemented Carbide Cutting Tools

采用固体粉末真空渗硼工艺 ,研究了硬质合金工具表面真空渗硼预处理对金刚石涂层附着力的影响。研究结果表明 ,硬质合金工具通过固体粉末真空渗硼处理 ,表面生成具有较高稳定性的以CoWB、CoB为主的渗层 ;经过长时间的金刚石涂层后 ,硬质合金工具表面出现Co3B和W2 Co2 1B6 相 ,没有单质Co相出现 ,克服了金刚石沉积中硬质合金表面钴的不利影响 ,使标志金刚石涂层附着力的压痕测试的临界载荷达到了15 0 0N 。

A novel boronizing process in vacuum has been developed in order to improve the reproducibility of techniques for preparing CVD diamond coated cemented carbide inserts.Diffusing boron in vacuum into the insert of WC 6%Co produced an interlayer of cobalt boride,such as W 2Co 21 B 6 and Co 3B.Investigation showed that the formation of the cobalt boride interlayer favored the growth of high quality diamond films,and the interlayer functioned effectively as a diffusion barrier,inhibiting outward Co migrations from the insert interior to the surface.Adhesion of the boronized interlayer as well as the composite coatings was evaluated by using Rockwell indentation and reached to 1500N.