无压浸渗法制备Al_2O_3颗粒增强铝基复合材料

Al_2O_3 Particles Reinforced Aluminium Matrix Composite Fabricated by Pressureless Infiltration Technique

采用无压浸渗法制备了Al2O3/Al复合材料,研究了材料的微观组织与力学性能。复合材料组织致密,颗粒分布均匀,无偏聚现象。铸造态复合材料的Al2O3颗粒表面存在界面反应物,经过透射电镜观察和XRD分析确认该反应物为MgAl2O4。T6处理后界面反应程度加剧,但弯曲强度达到439.4MPa,断口中撕裂棱和韧窝的数量较少,以颗粒的脆性断裂为主。Al2O3/Al复合材料中界面反应的存在提高了润湿性,促进了无压自发浸渗。

The Al2O3 /Al composite was fabricated by pressureless infiltration technique, and its microstructure and mechanical properties were investigated. The composite is dense. The particles are distributed uniformly in the composite, and no particle agglomeration is found. Interfacial reactions are found in the as-cast composite and the reaction product is identified as MgAl2O4 by TEM observation and XRD analysis. T6 treatment aggravates the interfacial reactions, but the composite after T6 treatment has a bending strength of 439.4 MPa. Few tearing ridges and micro-dimples are found in the fractures and the brittle failure of particles is dominant. The interfacial reactions enhance the wettability and promote the spontaneous infiltration process.