Mechanical Property of Roll Cast Al-11Si Alloy

摘要

Al-11%Si(-0.44%Fe-0.16%Cu-0.14%Mg) was cast into a strip using a vertical type high speed twin roll caster at a speed of 60m/min. The cooling rate of the strip was ranging from 2000°C/s at the surface to 1000°C/s at the center of the thickness. The eutectic Si was smaller than 2μm. The homogenization, cold rolling down to 1mm, and annealing were carried out before tension tests, 180 degrees bending tests and deep drawing tests. The tensile stress was 192MPa, the 0.2% proof stress was 84MPa, and the elongation was 23.8%. Roll cast Al-11%Si had excellent elongation. The specimen was not broken by the 180 degree bending. LDR (Limiting Drawing Ratio) of the deep drawing test was 1.8. The ductility was drastically improved by the high speed twin roll caster. These results show that roll cast Al-1 l%Si has ability to be used for the sheet forming. Moreover, the Fe content was increased up to 1.0% as a model of a recycled alloy. The elongation was 15.9% and the LDR was 1.7. Al-Si-Fe intermetallics became fine by the effect of rapid solidification. As a result, deterioration of the ductility was improved.