三维碳化硅结构增强铝基复合材料的制备

采用有机泡沫体浸渍工艺制备了具有三维骨架结构且气孔相互连通的碳化硅多孔陶瓷预制体,使用无压浸渗工艺制备了三维碳化硅结构增强的金属铝基复合材料,同时探讨了无压浸渗过程的反应机理及动力学过程,用XRD、SEM、光学显维镜研究了预制体和复合材料的金相组成及显维组织结构。结果表明,在金属熔体中引入合金元素Si和Mg等元素能破坏氧化铝膜,缩短无压浸渗过程的孕育期。浸渗温度越高,浸渗速度就越快。

Preparation of three- dimensional structure silicon carbide reinforced aluminum matrix composites

The open cell silicon carbide porous ceramic performs were prepared by impregnating a polyurethane sponge with aqueous ceramic slurry. Three - dimensional structure silicon carbide reinforced aluminum matrix composites were made by a pressureless molten metal infiltration process. The reaction mechanism and dynamics of infiltration process were discussed. The phase composition of the preform and composites were determined by XRD, its structures were characterized by SEM. The results show that the alloying elements Mg and Si in aluminum can destroy alumina film, markedly shorten the incubation period of infiltration process. The higher the infiltration temperature, the shorter the infiltration time.