基于真空热压扩散法的金刚石/Ti界面生成机制

Formation mechanism of diamond/Ti interface based on vacuum hotpressing diffusion method

采用真空热压扩散法在聚晶金刚石表面制备Ti层,探究金刚石表面金属化过程中的界面生成机制。利用扫描电子显微镜和X射线衍射仪,分析了钛层的表面形貌、界面结构和界面间的物相组成,采用能谱仪对界面进行了元素分析,计算了聚晶金刚石与Ti层之间界面的扩散带宽度及生成TiC的化学反应吉布斯自由能变。研究结果表明:在聚晶金刚石表面形成了平整、致密的Ti层,在聚晶金刚石与Ti层界面之间存在C、Ti和Co元素的扩散,在结合界面处产生了一定宽度的元素扩散带,同时在金刚石表面生成了点状TiC。真空热压扩散法实现了金刚石与Ti层的化学结合,可以提高金刚石与Ti层的结合强度。

With the vacuum hot pressing diffusion method,Ti coating layer was prepared on the surface of polycrystalline diamond to investigate the formation mechanism of the interface during diamond metallization.The surface morphology,interface structure and phase composition of the Ti coating layer were analyzed with a scanning electron microscope and an X-ray diffractometer.The interfacial elements were analyzed with an energy disperse spectrometer.The width of the element diffusion zone between polycrystalline diamond and Ti layer and the free enthalpy change for the chemical reaction to generate TiC were calculated.The research results show that flat and dense Ti layer is formed on the surface of polycrystalline diamond.There is diffusion of carbon,Ti and cobalt elements on bonding interface between Ti coating layer and polycrystalline diamond.An element diffusion zone with a certain width is generated on bonding interface.At the same time,spot-shaped TiC particles are formed on diamond surface.The vacuum hot pressing diffusion method can realize a chemical combination between diamond grain and a Ti layer,and can improve the bonding strength between diamond grain and Ti layer.