铸铁表面原位合成TiC/Al_3Ti复合材料

In Situ Synthesis of TiC/Al_3Ti Composites on Cast Iron Surface

对Al-Ti-C体系进行热力学分析,在氩气保护下进行热爆反应试验。采用铸造反应合成技术在铸铁表面原位合成TiC/Al3Ti复合材料。研究热爆产物及表面复合材料的物相、组织和界面形貌,并对其形成机理进行探讨。结果表明:采用热爆工艺使Al-Ti-C体系发生反应,生成纯净的TiC/Al3Ti复合产物。在熔融铁液作用下,Al-Ti-C体系反应完全,制备出纯净的TiC颗粒增强金属间化合物基表面复合材料。表面复合材料组织致密,与铁基体界面为良好的冶金结合。当TiC含量较少时,颗粒呈条状;随着TiC含量的提高,颗粒尺寸逐渐减小,由长条状向粒状及细粒状转化。

The thermodynamic analysis and thermal explosion test in an argon atmosphere for Al-Ti-C system alloys were carried out. The TiC/Al3Ti composite coating was in situ fabricated on the surface of cast iron by means of the reaction synthesis in melt. Phase, microstructure and interface morphology of the thermal explosion products and the composites were investigated. The formation mechanism of the composite coating was also discussed. The results show that TiC and A13Ti could be synthesized as final products through the thermal explosion reactions of Al-Ti-C system. A TiC-reinforced A13Ti intermetallic matrix composite was successfully fabricated on an iron substrate by the thermal explosion of Al-Ti-C system during casting. The composite is compactly formed on iron surface with a metallurgical bonding interface. TiC presented a strip form as the content of TiC is 20 wt.%; with an increase of TiC, its shape changes from the strip form to granular form with decreased size.