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金刚石涂层硬质合金是一种出众的刀具材料,将碳化硅掺入金刚石涂层中不仅可以提高涂层的断裂韧性,还能够提高薄膜与基体之间的粘附性。文章采用氢气、甲烷和四甲基硅烷混合气体作为反应气体,用直流等离子体辅助热丝化学气相沉积法在硬质合金基体上沉积金刚石-碳化硅-硅化钴复合薄膜。通过扫描电子显微镜、电子探针显微分析、X射线衍射和拉曼光谱对薄膜的表面形貌、成分以及结构进行了分析,结果显示此复合薄膜中含有金刚石、碳化硅(β-Si C)和硅化钴(Co2Si、Co Si)。复合薄膜的结构和成分可通过调节偏流和气相中四甲基硅烷的浓度来控制,随着偏流的增加,复合薄膜中金刚石晶粒尺寸变大且含量增加,β-Si C的含量减少,因为复合薄膜沉积过程中正偏压促进金刚石的生长,并且增强金刚石的二次形核。虽然电子轰击同时增强了氢气、甲烷和四甲基硅烷的分解,但随着偏流的增加,气相中产生的碳源浓度高于硅源浓度,使金刚石比β-Si C在空间生长上更具有优势。当偏流过高时则形成纯金刚石,不能够同时沉积金刚石、β-Si C和硅化钴三种物质。通过调节偏压和气体成分,金刚石和碳化硅在复合薄膜中的分布得以控制。该工作有助于理解和控制复合材料和超硬薄膜的生长,所产生的复合薄膜可用于提高金刚石涂层刀具切削性能。
Diamond Coated Carbide is a superior tool material that incorporates silicon carbide into the diamond coating to improve not only the fracture toughness of the coating but also the adhesion between the film and the substrate. In this paper, a mixed gas of hydrogen, methane and tetramethylsilane was used as a reactive gas to deposit a diamond-silicon carbide-cobalt silicide composite film on a cemented carbide substrate by DC plasma assisted hot filament chemical vapor deposition. The surface morphology, composition and structure of the films were analyzed by scanning electron microscopy, electron probe microanalysis, X-ray diffraction and Raman spectroscopy. The results show that the films contain diamond, silicon carbide (β-Si C) And cobalt silicide (Co2Si, Co Si). The structure and composition of the composite film can be controlled by adjusting the bias current and the concentration of tetramethylsilane in the gas phase. As the bias current increases, the diamond grain size in the composite film increases and the content increases, and the content of β-Si C decreases The positive bias during composite film deposition promotes the growth of diamond and enhances the secondary nucleation of diamond. Although electron bombardment enhances the decomposition of hydrogen, methane and tetramethylsilane, with the increase of bias current, the concentration of carbon source in the gas phase is higher than the concentration of silicon source, making the diamond more specific than β-Si C in space growth Advantage. When the bias current is too high when the formation of pure diamond, can not simultaneously deposit diamond, β-Si C and cobalt silicide three substances. By adjusting the bias and gas composition, the distribution of diamond and silicon carbide in the composite film is controlled. This work helps to understand and control the growth of composites and superhard films, and the resulting composite films can be used to improve the cutting performance of diamond coated tools.