Effect of iron content on the surface quality of 6063 aluminum alloy extrusion

摘要

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, #beta#-AlFeSi and Mg_2Si in cell boundaries during extrusion and the transformation of AlFeSi particles from #beta# to #alpha# during homogenization was effective to reduce pick-up. As the result of estimation of a ratio, a ratio increased with iron content in the as-cast ingots. Furthermore, it was confirmed that the transformation of AlFeSi particles from #beta# to #alpha# during homogenization was encouraged with higher iron content. Then, there was a good correlation between pick-up and a ratio. From the view point of surface roughness, R_z decreased with iron content because heavy pick-up defects decreased with increasing iron content. On the other hand, R_a increased with iron content because die line became severely.