金刚石增强Na2O-B2O3-Al2O3-SiO2系陶瓷基复合材料的界面研究

以Na₂O-B₂O₃-Al₂O₃-SiO₂系低温玻璃为基础结合剂烧制金刚石增强陶瓷基复合材料,利用扫描电子显微镜、X射线能谱、X射线光电子能谱、拉曼光谱及力学性能测试仪等对其界面结合强度、界面处元素分布及界面化学键进行了表征。结果表明,Na₂O-B₂O₃-Al₂O₃-SiO₂系陶瓷结合剂与金刚石颗粒界面结合强度高,790 ℃煅烧时试样抗折强度达到77.82 MPa。Si、B、Na、Zn各元素在界面位置发生扩散,而Al元素没有明显扩散,元素扩散提升了结合剂对金刚石的把持力。陶瓷结合剂与金刚石在界面处形成C-O、C=O和C-B键,化学成键进一步增进界面结合。另外,790 ℃煅烧的复合材料中金刚石颗粒保存完好,而850 ℃煅烧时金刚石出现石墨化迹象。

Research on Interface of Diamond Reinforced Na2O-B2O3-Al2O3-SiO2 Ceramic Matrix Composite Materials

The diamond reinforced ceramic matrix composite with Na₂O-B₂O₃-Al₂O₃-SiO₂ low-temperature glass as basic binder was fired. The interface bonding strength, interface element distribution and interface chemical bonds were characterized by scanning electron microscopy, X-ray energy spectroscopy, X-ray photoelectron spectroscopy, Raman spectroscopy and mechanical property testing. The result indicates that the interface of Na₂O-B₂O₃-Al₂O₃-SiO₂ vitrified bond and diamond particle has high bonding strength. The flexural strength of sample fired at 790 ℃ reaches 77.82 MPa. The elements of Si, B, Na and Zn diffuses at the interface position, but the element of Al does not diffuse significantly. The holding force of vitrified bond on diamond is improved by element diffusion. The C-O, C=O and C-B chemical bonds are formed at the interface between vitrified bond and diamond, the interface bonding is further enhanced by chemical bonds formation. In addition, the diamond particles in composite fired at 790 ℃ are well preserved, however, the signs of graphitization are shown while the diamond in composite fired at 850 ℃.