Fracture and drop-off of diamond grains are thought to be suppressed if the diamond grains used, such as those for electroplated wires, are coated with a material having a higher coefficient of thermal expansion than diamond and having good adhesion to the binder metal. In this study, we selected titanium carbide and titanium carbonitride as materials with such characteristics, and investigated their coating methods. The titanium carbide coating was formed by heating a mixture of diamond plate or diamond grains and titanium powder in vacuum at a temperature lower than the melting point of titanium. Titanium carbonitride formation tests were performed in two ways: by forming a titanium carbide coating and titanium carbonitride in the same chamber continuously or by exposing the sample to the atmosphere after titanium carbide formation and subsequently reheating it in nitrogen. The titanium carbide coating was tested by heating the mixture of the diamond plate and the titanium grains in vacuum of 2.0 × 10⁻³ Pa or less at 1073–1273 K for 60–120 min. For the titanium carbonitride coating, the primary titanium carbide coating was applied at temperatures of 1123–1273 K for 60 min. Then the titanium carbonitride formation was done at the same temperature but with different heating times. Products on the diamond after heating tests were analyzed using X-ray diffraction. Results show that titanium carbide can be coated onto the diamond surface by heating the mixture of diamond and titanium powder in vacuum at 1073 K or at a higher temperature. Results demonstrated further that titanium carbonitride can be formed by heating the diamond plate or the diamond grains coated with titanium carbide in nitrogen at a temperature higher than 1123 K. The titanium carbide layer thickness and the ratio of nitrogen in the titanium carbonitride increased concomitantly with increased heating temperature and increased heating time.

如果所用的金刚石颗粒，例如用于电镀线的金刚石颗粒，被涂覆有比金刚石具有更高的热膨胀系数并且对粘结剂金属具有良好粘附性的材料，则认为金刚石颗粒的断裂和脱落被抑制。在这项研究中，我们选择碳化钛和碳氮化钛作为具有这种特性的材料，并研究了它们的涂覆方法。通过在低于钛的熔点的温度下在真空中加热金刚石板或金刚石晶粒和钛粉末的混合物来形成碳化钛涂层。碳氮化钛形成测试以两种方式进行：通过在同一腔室中连续形成碳化钛涂层和碳氮化钛，或在形成碳化钛后将样品暴露于大气中，然后在氮气中重新加热，可以实现以下目的：通过在2.0×10的真空下加热金刚石板和钛晶粒的混合物来测试碳化钛涂层⁻³ 1073–1273 K时Pa或更小，持续60–120分钟。对于碳氮化钛涂层，主要的碳化钛涂层在1123–1273 K的温度下施加60分钟。然后在相同的温度下但以不同的加热时间完成碳氮化钛的形成。使用X射线衍射分析加热试验后钻石上的产品。结果表明，可以通过在真空中于1073 K或更高的温度下加热金刚石和钛粉末的混合物，将碳化钛涂覆在金刚石表面上。结果进一步证明，可以通过在高于1123 K的温度下在氮气中加热涂覆有碳化钛的金刚石板或金刚石晶粒来形成碳氮化钛。