ELEVATED TEMPERATURE LOW CYCLE FATIGUE BEHAVIOUR OF A COMMERCIAL Al-Fe-Si ALLOY UNDER ROTATING BENDING.

Deflection controlled low cycle fatigue tests were conducted under rotating bending (R equals minus 1) conditions on a commercial Al-Fe-Si alloy at 28, 100 and 200 degree C at a constant frequency of 50 cycles min. The effect of aging treatment on the low cycle fatigue behavior of the alloy was also determined. The material shows conflicting low cycle fatigue behavior at high and low strain amplitudes in elevated temperature experiments, which can be attributed to the interactions between the parameters like temperature, strain rate and age-hardening (precipitation of aluminum ferrosilicate. For age-hardening alloys like Al-Fe-Si, the stable structure obtained in the overaged condition is the best for low cycle fatigue resistance, in view of the better ductility coupled with comparable ultimate tensile strength at peak hardness.