采用粉末注射成形/无压浸渗法成功制备出了SiC体积分数为63%的SiCp/Al复合材料.重点研究了主要工艺参数对SiC骨架及复合材料性能的影响规律.研究表明,采用粉末注射成形制备的SiC骨架经1100℃预烧后,仍具有很高的开口孔隙率,达到总孔隙率的97.9%.SiC颗粒经高温氧化处理后所生成的SiO2薄膜可明显改善铝合金熔液与SiC颗粒之间的润湿性,显著提高复合材料的密度.通过对工艺参数的优化可使铝液较好地润湿SiC骨架,获得最高相对密度可超过97%的复合材料.
SiCp/Al composites with 63 % SiC in volume fraction were successfully prepared by powder injection molding and pressureless infiltration. The effects of major processing parameters on the properties of SiC preforms and SiCp/Al composites were investigated. The results showed that SiC preforms pre-fired at 1100 ℃ or lower temperature exhibited high open porosity, which is over 97.9 % of the whole porosity. The SiO2 film resulting from the oxidation of SiCp at high temperature can remarkably enhance the wettability of SiCp by Al alloy liquid, leading to a significant increase in density of the composites. After optimization of the processing parameters, the SiC performs were well wetted by Al alloy liquid. As a result, an SiCp/Al composite with a higher relative density of over 97 % was obtained.