Al合金溶湯中のSiC粒子分散挙動に及ぼす添加元素の影響

抄録

The effect of anoying elements on dispersion of SiC particles into molten aluminum was investigated. The time required for incorporation of SiC particle into molten aluminum was defined as an incorporation time. The incorporation time of SiC was shortened by alloying magnesium, or by alloying titanium together with tin. These alloying elements have strong affinity for SiC and are able to form silicide as a result of reaction with SiC. Magnesium silicide was detected by using EPMA, although the existence of titanium silicide couldn’t be confirmed. The incorporation time of SiC was prolonged by adding zinc, copper or tin which has no affinity for SiC. Moreover, particulate dispersion is considerably influenced by surface-active elements. The incorporation time of SiC particle was shortened by adding lithium, that was a surface-active element with strong affinity for SiC, whereas it was prolonged by adding the surface-active elements such as lead or bismuth, having weak affinity for SiC. This is probably because lead or bismuth hinders the wetting between SiC particle and molten aluminum, adsorbing at the interface. The addition of silicon into aluminum prolonged the incorporation time of SiC, because the dissociation of SiC, that might be necessary for good wetting, was controlled by the presence of silicon.