W18Cr4V高速钢渗铬热处理对HFCVD金刚石膜生长的影响

Effect of high temperature diffusion chromizing pretreatment of W18Cr4V high-speed steel on growth of diamond films by HFCVD

采用热丝化学沉积法在高速钢基体上沉积金刚石薄膜。为了减少石墨的形成、增强膜基结合强度,沉积前先使用渗铬热处理在高速钢表面制备一层碳化铬中间层。采用场发射扫描电子显微镜、X射线衍射仪、激光拉曼光谱和洛氏硬度计对渗铬基体和金刚石膜进行检测分析,研究渗铬热处理对高速钢基体与金刚石膜的物相组织、结构形貌和附着性能的影响。结果表明:渗铬热处理能在钢基表面形成一层致密的富Cr层,此过渡层能有效提高金刚石的形核率,在渗铬钢基表面形成连续致密的高质量金刚石膜,但该金刚石膜的应力较大,1 471N载荷的压痕测试导致薄膜严重破坏,说明膜基结合强度有待进一步提高。

Diamond films were grown on high-speed steel substrates by hot filament chemical vapour deposition（HFCVD） method.A chromium carbide coating prepared by high temperature diffusion chromizing pretreatment was used as an intermediate layer on the steel substrates to minimize the early formation of graphite and to enhance the diamond film adhesion.The characteristics of the chromizing pretreated high-speed steel and the diamond films were analyzed by X-ray diffractometer（XRD）,field emission scanning electron microscope（FE-SEM）,micro-Raman spectroscope and Rockwell hardness indentation to investigate the effects of chromizing pretreatment on the morphology,structure and adhesion of the substrate and diamond films.The results show that chromizing high speed steel results in the formation of a Cr-rich layer on the substrate surface,which leads to a much improved nucleation density,and formation of smooth,dense,good quality diamond films,but the thermal stress of diamond films is large,Rockwell indentation testing with 1 471N shows serious damage,implying that the adhesion of these films is not good enough.