Si对无压浸渗SiC_p/Al复合材料显微组织与热导率的影响

Effect of Si on the microstructure and thermal conductivity of pressureless infiltrated SiC_p/Al composites

研究了Al-8Mg基体中添加Si对无压浸渗SiCp/Al复合材料显微组织和热导率的影响.结果表明,Si能够改善Al与SiC的润湿性,减少复合材料孔隙度,抑制界面反应,提高相对密度.不含Si时,Al与SiC界面反应严重,并且润湿性较差,导致复合材料的热导率和相对密度较低;当基体中添加质量分数12%的Si时,界面反应受到完全抑制,热导率取得最大值;进一步提高基体中Si含量,由于铝基体的热导率随Si含量的增加而降低,导致复合材料的热导率也随之降低.

The effects of the amount of Si added to Al-8Mg alloy on the microstructure and thermal conductivity of pressureless infiltrated SiCp/Al composites were investigated. The results show that Si addition to matrix can reduce the porosity of the infiltrated composites by the improvement of SiC/Al wettability, suppress the SiC/Al interracial reaction and increase the relative density of the infiltrated composites. Without Si addition to At-SMg alloy, the composites exhibited a lower thermal conductivity and relative density because of poor wettability and severe interracial reaction. With increasing the Si content to 12 %, the interracial reaction was suppressed and the thermal conductivity of the composites is the maximum. With further increasing Si content, the thermal conductivity of the composites decreased because the thermal conductivity of matrix itself decreased.