抄録
The effect of iron content on the surface quality of 6063 aluminum alloy extrusions was investigated. From the view point of surface defects, pick-up decreased with iron content. In our previous paper, it was found out that pick-up defects were caused by peritectic reaction of Al, β-AlFeSi and Mg2Si in cell boundaries during extrusion and the transformation of AlFeSi particles from β to α during homogenization was effective to reduce pick-up. As the result of estimation of α ratio, α ratio increased with iron content in the as-cast ingots. Furthermore, it was confirmed that the transformation of AlFeSi particles from β to α during homogenization was encouraged with higher iron content. Then, there was a good correlation between pick-up and α ratio. From the view point of surface roughness, Rz decreased with iron content because heavy pick-up defects decreased with increasing iron content. On the other hand, Ra increased with iron content because die line became severely.
