【作者】 王俊；

【导师】 张长军；

【作者基本信息】 长安大学 ， 材料学， 2009， 硕士

【摘要】 碳化钛(TiC)是一种低密度(4.93g/cm~3),高熔点(3140℃),高弹性模量(460GPa)的陶瓷材料。由于其具有较低的反应生成自由能,因而是一种很有潜力的以抗磨料磨损为目标的颗粒增强金属基复合材料的硬质相。但是由于要获得高纯度、理想尺寸的TiC颗粒难度很大,即使制备了理想尺寸的TiC,也会加大生产成本,这样就限制了它作为颗粒增强体的工业应用。由于铁(Fe)基材料成本低廉、物理和力学性能优异,近年来越来越受到重视,而且Fe还常与Ti伴生,Ti/Fe粉价格也低,因此用Fe基材料作TiC的粘结相原料相当合适,并可大大降低生产成本。本文采用真空无压烧结法,以碳化钛超细粉和来源广泛铸铁粉为原料制备了TiC加入量在30～60(wt%)之间的TiC复合材料。采用金相显微镜(OM)、扫描电镜(SEM)、能谱分析(EDAX)、X衍射等分析手段,较系统地研究了TiC加入量对复合材料微观组织、力学性能的影响。结果表明:试样中主要的相组成为Fe和TiC,其显微组织均匀,界面结合良好,没有明显的裂纹和撕裂,二者之间达到了非常好的冶金结合。对材料的性能而言,TiC在基体中分布的均匀性越好,复合材料的机械性能越好,并随TiC体积分数的增加,其硬度、强度均有了大幅度提升。随后以不同粒度的SiC为磨料,在不同载荷条件下采用销—盘磨损试验机测试复合材料的二体磨料磨损行为。试验结果表明,TiC复合材料具有较高的抗磨料磨损能力,且其耐磨性随着碳化钛粉体积分数的增大而提高,尤其是在低载荷、细磨料磨损条件下,复合材料表现出极为优越的耐磨性,与高铬铸铁相比有大幅度的提高。更多还原

【Abstract】 Duing to its special properties, such as low-density (4.93g/cm3), high melting point (3140℃), high elastic modulus (460GPa) and lower free energy of the reaction, Titanium carbide (TiC) is a technogically important ceramic material. It is a potential hard phase for the target of anti-abrasive wear of particle reinforced metal matrix composites. However, it is very difficult to obtain the high purity and ideal size of TiC particles, even if an ideal size of TiC was fabricated, which will be increased the production costs and limited its industrial applications as reinforcement particles.Ferrous(Fe) matrix materials is more and more important in recent years for its low-cost, excellent physical and mechanical properties. And Ferrous is also often associated with Titanium, the prices of Ti/Fe powder are also low, therefore the binding phase of Fe-based materials are very suitable raw materials for TiC and production costs will be reduced significantly.In this dissertation, Vacuum sintering without pressure technology is used to fabricate the high volume TiC composite with the ultra-fine titanium carbide and cast iron powder of raw materials. The microstructure, mechanical properties as well as wear resistance have been extensively investigated using optical microscope(OM) , scanning electron microscope(SEM), X-ray diffractometer(XRD) and other modern equipments. The result indicated that the fabricated composites consisted of Fe and TiC, its uniform microstructure, Good interfacial bonding, no crack and tear, which showed that well metallurgical bonding was reached between the two. Performance in terms of materials, the more uniformity of distribution, the better mechanical properties of composite materials as possible, and its hardness, strength has been improved significantly with the increase of TiC volume fractionPin on disk two body abrasion tests have been performed with different abrasive particle size of SiC under different load conditions. The results show that the wear resistance increases with the particle content. The composite shows better wear resistance than high chromium cast iron material especially in low load and fine abrasive test condition.更多还原