熔铝氧化渗透合成SiC_p/Al_2O_3-Al复合材料的微观结构分析

以低成本的熔铝氧化渗透合成新方法制备了SiCp/Al2 O3 Al复合材料。借助X光电子谱 (XPS)、光学金相显微镜、透射电镜 (TEM)、X射线衍射 (XRD)等手段研究了该种复合材料的微观结构 ,并分析了影响微观结构的主要因素及其影响规律。结果表明 ,Al2 O3 和Al作为复合材料基体呈双连续分布 ,它们各自的含量可在较大范围内受SiC颗粒的粒度所控制。在熔铝氧化渗透合成的SiCp/Al2 O3 Al复合材料中 ,各组成相之间无界面反应 ,也无晶间相 ,Al2 O3 在SiC颗粒表面二次形核并直接生长的现象普遍存在 ,并由此形成了具有良好物理冶金结合的Al2 O3 SiC一体化陶瓷骨架

Investigation on the microstructure of SiC_p/Al_2O_3-Al composites synthesized by oxidative infiltration of Al melt

SiC p/Al 2O 3 Al composites were synthesized by oxidative infiltration of Al melt at low cost. The microstructures of the synthesized composites were investigated using X ray photoelectron spectrometer, optical microscopy, transmission electron microscopy, X ray diffraction. The key controlling factor and controlling rule on microstructures of the composites were analyzed. The result indicates that the amount of co continuous Al 2O 3 and Al (Si) phases in composites can be tailored by properly choosing SiC particle size. In the synthesized SiC p/Al 2O 3 Al composites, no reaction product or impurity phase is observed at the interface between various phases or grains. The second nucleation and direct growth of Al 2O 3 at the surface of SiC particle frequently occurs, which in turn form the integral Al 2O 3 SiC ceramic skeleton with excellent physical metallurgy bond.