钛过渡层与硬质合金基体表面结合状况对金刚石薄膜附着力的影响

以WC-6％Co为基体，采用磁控溅射法，在原始试样、酸腐蚀试样以及酸蚀后进行氢等离子体脱碳处理的试样上制备Ti过渡层，然后碳化过渡层为TiC。在热丝化学气相沉积装置中，制备金刚石薄膜。研究三种不同试样上的金刚石薄膜与基体的附着力。结果表明，在原始试样上的金刚石薄膜在冷却过程中自动脱落；在经等离子体处理后的试样上，金刚石薄膜与基体间附着力高于在经酸蚀处理的试样上的金刚石薄膜与基体附着力。造成这种现象的主要原因可能是等离子体脱碳还原处理降低WC晶粒表面能，增强Ti与WC间的结合强度，导致TiC过渡层与WC基体结合强度增加，从而增加金刚石薄膜附着力。

EFFECT OF BONDING STATE BETWEEN TITANIUM INTERLAYER AND CEMENTED CARBIDE SUBSTRATE ON THE ADHESION OF CVD DIAMOND FILM

Titanium interlayer was prepared by magnetron-sputtering on untreated, acid pretreated and acid pretreated followed by hydrogen plasma decarburizated cemented carbide substrate respectively. The titanium interlayer was then carburized into TiC. Diamond film was coated by the hot filament chemical vapor deposition method. The adhesion of diamond on three substrates was investigated. It was found that the diamond film on original substrate fall off directly during the cooling process. The adhesion of diamond films on the substrate pretreated by hydrogen plasma was higher than that of film on substrate treated by acid. This effect may be due to the plasma decarburization and recarburization, which decreased the surface energy of WC grains, enhanced the bonding strength between Ti and WC, accordingly increased the bonding strength between TiC interlayer and WC substrate, and therefore, improved the adhesion of diamond coating consequently.