Ce及Mg对SiC_p/Al复合材料界面润湿性的影响

Study on the Influence of Ce and Mg on the Interface Behavior of SiC_p/Al Composites

采用液态搅拌法制备了SiCp/ZL105复合材料,并对其界面行为进行了研究。试验结果表明,表面活性元素Mg的加入能降低铝合金熔体的表面张力,进而改善SiC颗粒与铝基体间的界面润湿性,增强SiC颗粒与基体间的浸润复合;而加入富铈混合稀土后没有收到明显的效果。分析认为,Mg对铝液表面张力及其在颗粒表面润湿性的改善是通过在颗粒与熔体间引发了化学反应达到的,并非仅物理作用。在本试验条件下,Mg的加入引发了MgAl2O4在颗粒表面的生成,达到了改善界面润湿性的效果;而富铈稀土加入后,未在SiC颗粒与铝熔体间引发界面反应。

Interface behavior of SiC_p/Al composites, which was fabricated by melt stirring casting, have been researched. With the addition of a surface-active element magnesium to aluminum melts, surface tension of molten aluminum is reduced, therefore wetting behavior and reactivity between molten aluminum and SiC particles are improved. But it was not found that Ce-rich mischmetal (65wt% Ce) has an obvious effect on the interface wet ability between molten aluminum and SiC particles. It is chemical reaction, not only physical action by which wet ability was improved. Under this trial conditions,with the addition of magnesium to aluminum melts, magnesium aluminate (spinel), MgAl_2O_4, is found at the interface as a reaction product, but with the addition of Ce-rich mischmetal, no reaction was carried out.