The influence of chemical composition on the microstructure and mechanical
properties of Al-6.6Mg and Al-5.5Mg (wt-%) alloys was investigated. The res
ults show that the increase in Mg content can improve the tensile strength
and ductility. However, there is no corresponding increase in fatigue stren
gth. Low fatigue strength of the Al-6.6Mg alloy could be attributed to inte
rgranular fatigue fracture. MST/4323.