中文摘要：

研究了流动Ar和Nz对镀铬金刚石热处理后镀层组织的影响，热处理温度分别为450℃、650℃和850℃，采用XRD、SEM和EDS方法对镀层组织进行了研究。研究结果表明，流动Ar时镀层易发生氧化，在较低的温度（如650℃）氧化已经十分显著，不同的是，流动Nz氧化温度升高到850℃。在两种气氛下均发现，当热处理温度由650℃升至850℃时，镀层中碳化铬由低C／Cr相Cr，C3向高C／Cr相Cr3C2发生转化，且在氮气备件下转化率更高。上述现象归因于N2与镀层中的Cr反应生成了CrN，阻碍并延迟了镀层的氧化，有利于高温下金刚石表面的C原子与镀层中的Cr原子相互扩散。

英文摘要：

Effect of flow Ar and N2 on the microstructure of chromium coating on the diamond after heat treatment was investigated. Heat treatment temperatures were selected as 450℃, 650℃ and 850℃, respectively. The analysis of coating microstructure was conducted by XRD, SEM and EDS. Research results indicate that Ar-flow coating was apt to oxide, especially at lower temperature, i.e. 650℃, at which the oxidation was more evidently. On the contrary, the oxidation temperature in N2-flow coating rised to 850℃. In both atmospheres, it was found that with increasing heat treatment temperature from 650℃ to 850℃, the amount of carbide transformed from Cr7C3 with low C/ Cr ratio to Cr3 C4 with high C/Cr ratio, and this carbide transformation was enhanced in N2 atmosphere. The results of studying coating by XRD, SEM and EDS indicate that the reaction of N and Cr to form CrN in N2 atmosphere, which both prevented the coating oxidation and enhanced the inter-diffusion of C atom from diamond and Cr atom from coating at high temperature.