Strain rate sensitivity of hot deformed Al and AlMgSi alloy

Hot compression tests, at a constant true strain rate, were performed on a solution treated AlMgSi alloy. Strain and precipitation hardening of the alloy was observed during deformation at intermediate temperatures. The hardness maximum for specimens deformed to ε = 0.5 at strain rate of 1.3 × 10−2 S−1 and 1.3 × 10−3 s−1 was observed at deformation temperatures of 510 K and 470 K respectively. Strain rate sensitivity measurements were performed during hot deformation in the strain range of ε = 0.05-0.5. For comparison, additional tests were also performed for the overaged alloy, and for pure aluminium, to test the effect of solutes and structural changes during deformation. The strain rate sensitivity was found to be temperature dependent for the materials used in the experiment. Moreover, the strain rate sensitivity of solution treated AlMgSi alloy was found to be strain dependent and possible reasons of this effect were discussed.