金刚石表面镀钛及其在胎体中结合状态的研究

Study on the titanium plating on diamond surface and its bonding state in the matrix

采用真空蒸发–扩散镀的方法在金刚石表面镀钛,研究了镀覆温度和保温时间对金刚石表面形貌、镀层厚度、镀层物相的影响规律,分析了镀钛金刚石的抗氧化性能,研究了镀钛金刚石及其在铁基胎体中的结合状态。结果表明:在低温下(680℃)镀覆时,金刚石表面开始出现TiC;随镀覆温度升高或保温时间延长,镀层逐渐致密并增厚,在720℃镀覆时出现Ti沉积,在820℃镀覆时由于应力原因产生裂纹并导致镀层的破坏;镀层可隔绝金刚石与氧的直接接触,大幅度延缓氧对金刚石的侵蚀作用;镀钛后金刚石在胎体中可实现牢固的冶金键合。

The method of vacuum evaporation-diffusion plating was used to plate titanium on diamond, the effects of plating temperature and holding time on diamond surface morphology, coating thickness and coating phase were studied, and the anti-oxidation performance of Ti-coated diamond was analyzed as well as its bonding state in iron matrix. The results showed that TiC appeared at low temperature（680 ℃）. The plating temperature increasing or the holding time prolonging, the coating became denser and thicker, titanium deposition occurred at 720 ℃, cracks occurred due to stress and led to the destruction of the coating at 820 ℃. The coating isolated the direct contact between diamond and oxygen, and the erosion of diamond by oxygen was greatly delayed. After titanium plating, the diamond achieved solidly metallurgical bonding in the matrix.