【作者】 温光浩；

【导师】 熊惟皓；

【作者基本信息】 华中科技大学 ， 材料学， 2007， 硕士

【摘要】 本文对金属间化合物NiAl的性能、制备方法和Ti(C,N)基金属陶瓷的研究进展进行了综述。在此基础上,用金属间化合物NiAl取代TiC-10TiN-30Ni-15Mo-7.5WC-1.5C -0.6Cr3C2(wt%)中部分或全部粘结相Ni,制备了9种不同成分的Ti(C,N)基金属陶瓷,并采用离心粒度分析仪、热重分析仪(TGA)、金相显微镜(OM)、X射线衍射仪(XRD)、扫描电子显微镜(SEM)、X射线能量色散谱仪(EDS)、硬度计、抗弯强度测试仪等手段,探讨了NiAl含量对Ti(C,N)基金属陶瓷组织结构和性能的影响,为更高温度场合使用的Ti(C,N)基金属陶瓷成分设计提供一些理论指导。含20wt%NiAl、不含NiAl的两种金属陶瓷真空烧结过程中组织结构演变过程表明,前者的合金化起始温度为1450℃,比后者大约高200℃。含20wt%NiAl的金属陶瓷在900℃~1350℃温度区间烧结时,合金化过程不明显;1450℃~1600℃温度区间烧结时,合金化过程很充分,具有典型的芯-壳结构,核心硬质相为Ti(C,N)固溶体,环形相为(Ti,W,Mo)(C,N)固溶体,粘结相为固溶了大量Mo、W和Ti的NiAl固溶体。在NiAl含量为10~30wt%的范围内,随着NiAl含量增加,Ti(C,N)基金属陶瓷的硬质相晶粒越细小、分布越均匀,且被环形相包覆越好,组织越致密。含30wt%NiAl的金属陶瓷室温力学性能最佳,抗弯强度710MPa、硬度88.2HRA;800℃~1150℃温度区间恒温氧化3h后,增重速率最低,这有利于其在更高的温度下推广使用。更多还原

【Abstract】 In this thesis, the properties and preparing methods of intermetallic compound NiAl and the development of Ti(C,N)-based cermets were reviewed. Based on the above work, nine Ti(C,N)-based cermets were prepared by replacing a part or the whole of Ni in TiC-10TiN-30Ni-15Mo-7.5WC-1.5C-0.6Cr3C2 (wt%) with NiAl. The influences of NiAl content on the microstructures and properties of Ti(C,N)-based cermets were investigated, in order to supply some theoretic references for their composition design used at higher temperature, by means of centrifugal particle-size analyzer, thermogravitic analyzer (TGA), optical microscopy (OM), X-ray diffraction analysis (XRD), scanning electron microscopy (SEM) and energy dispersive spectrometry (EDS).According to the microstructure evolutions of two cermets with 20wt% and without NiAl during vacuum sintering, it was found that the initial alloying temperature of the former was 1450℃, which was higher about 200℃than that of the latter. For the former, it didn’t obviously alloy at the temperature between 900℃and 1350℃, and it obviously alloyed at the temperature between 1450℃and 1600℃, and it had a classical core-rim microstructure which consisted of ceramic phase Ti(C,N), rim phase (Ti,W,Mo)(C,N), and binder phase NiAl containing much Mo, W and Ti.In the range of 10~30wt% NiAl, ceramic phase became smaller, distributed more evenly, were surrounded completer by rim phase and microstructure became denser with the increase of NiAl content. Moreover, Ti(C,N)-based cermets with 30wt% NiAl had the highest mechanical properties at room temperature which were transverse rupture strength 710MPa and hardness 88.2HRA, and had the lowest liveweight growth after isothermal oxidizing at the temperature between 800℃and 1150℃for 3h which was helpful for their usage at higher temperature.更多还原