| Title |
Fatigue Properties of Al - Mg Alloy Sheets for Auto - body Application |
| Authors |
김형욱(Hyoung Wook Kim),강석봉(Suk Bong Kang),강혁(Hyuk Kang),남기우(Ki Woo Nam) |
| Abstract |
The effect of Mg content on fatigue behavior in Al-Mg alloys for auto body applications was investigated in this study. The increase of Mg content in Al-5.5 wt% Mg and Al-6.6 wt% Mg alloys enhanced the tensile strength and elongation from 284 ㎫ and 26.4% to 321 ㎫ and 31.2%. But the Al-6.6 wt% Mg alloy showed lower fatigue strength compared to that of Al-5.5 wt% Mg alloy due to the small precipitates along grain boundaries. These small precipitates were identified as Al_8Mg_5 phase which plays an important role as fatigue crack initiation site. The fatigue limits of Al-5.5 wt% Mg and Al-6.6 wt% Mg alloys showed 0.56 and 0.44, respectively. The fatigue crack growth rate of Al-6.6 wt% Mg alloy sheets is faster than that of Al-5.5 wt% Mg alloy sheets. |