Cr过渡层沉积粘附型CVD金刚石膜的机理研究

研究了电沉积层作为过渡层沉积CVD金刚石膜的工艺，在硬质合金的Cr电沉积层上用热丝法沉积出CVD金刚石膜。利用SEM分析了电沉积层的形貌，利用EPMA分析了H等离子处理后电沉积层的断面，利用SEM和Raman分析了金刚石膜的表面形貌、成分，利用XRD分析了过渡层和CVD金刚石膜的结合面．利用压痕法研究了金刚石薄膜与基体的结合力。结果表明，H等离子处理使得硬质合全与Cr镀层成为冶金结合，提高了电沉积层的结合强度；在Cr过渡层与金刚石膜之间形成的Cr3C2和Cr7C3等碳化物有利于金刚石的成核和膜基结合强度的提高。

Deposition of CVD Diamond Thin Film on Carbide Substrate by Using of Electro-planting Interlayer

Diamond thin films were deposited by means of hot filament chemical vapor deposition (HFCVD) on the Cr interlayer electro-planted on cemented carbide substrate .The HFCVD process was discussed . The structure of Cr was studied by Scanning Electron Microscope (SEM) and the electron probe microanalysis (EPMA) was applied on the cross section Cr pretreated by H plasma. The structure and composition of CVD diamond thin film were studied by SEM and Raman Scattering Spectroscopy (RAMAN). The cross section between Cr and diamond film was characterized by means of X-ray diffraction (XRD). The mechanisms of adhesion strength between diamond film and electro-deposited interlayer were studied and discussed. The adhesion evaluated with the minimal indenting loading at which the diamond films are broken was tested. The experimental results show that the bond between electro-deposited Cr and cemented carbide changes from mechanical bond to metallurgical bond after H-plasma-pretreatment, and new phases of Cr 3C 2 and Cr 7C 3 are obtained under CVD conditions which are contribute to increasing nucleation density of diamond and improving the adhesion strength between diamond coating and Cr interlayer.