【摘要】 采用真空烧结（真空度小于3 Pa）制备不同Cr含量Ti（C,N）基金属陶瓷,探究Ti（C,N）基金属陶瓷900℃时的抗氧化性。结果表明,Cr元素能大大的提高Ti（C,N）基金属陶瓷的高温抗氧化性能。添加Cr元素的Ti（C,N）基金属陶瓷的氧化层为多层,氧化层的主要成分是NiCr₂O₄、NiWO₃、NiTiO₃,过渡层的主要成分是TiO₂。与未添加Cr元素的金属陶瓷相比,添加Cr元素能生成更多TiO₂和NiTiO₃相以及新相NiCr₂O₄和CrMoO₄。通过热力学数据进行吉布斯自由能计算,得到氧化物的稳定性不同,其反应的先后顺序也有差别,W元素和Cr元素优先被氧化,其次Mo、Ti、Ni被氧化,氧化物之间在高温的环境下会继续发生反应生成更为复杂的化合物构成氧化层的成分。通过机理分析,氧化可分为氧气侵蚀基体、氧化层生成和氧化层剥落3个阶段。更多还原

【Abstract】 Ti（C,N）-based cermets with different Cr contents were prepared by vacuum sintering（vacuum degree is less than 3 Pa）. The oxidation resistance of Ti（C,N）-based cermets at 900 ℃ was studied. The results show thatCr can greatly improve the high temperature oxidation resistance of Ti（C,N）-based cermets. The oxidation layer of Ti（C,N） based cermets with Cr addition is multilayer,the main components of oxide layer are NiCr₂O₄, NiWO₃ NiTiO₃, and the main component of the transition layer is TiO₂. Compared with the cermets without Cr element, adding Cr element can generate more TiO₂ and NiTiO₃ phases and new phases of NiCr₂O₄ and CrMoO₄. The Gibbs free energy calculation based on thermodynamic data shows that the stability of the oxide is different, and the order of reaction is also different. W element and Cr element are oxidized first,followed by Mo, Ti, Ni. The oxides will continue to react in a high temperature environment to form more complex compounds to form the components of the oxide layer. According to the mechanism analysis, the oxidation can be divided into three stages: oxygen erosion into the matrix, oxide layer formation and oxide layer peeling.更多还原