Effect of strain rate and temperature of tensile test on Luders strain in Al-Mg alloys

The effects of strain rate and temperature of tensile test on Luders strain in Al-4.4%Mg (commercial 5182 alloy) alloy were investigated and the results were compared with the reported case of Al-low Mg (5052) alloy. The morphologies of the yielded zones developed on the specimen surface during the tensile test were observed. The Luders strain was larger and more complex in Al-high Mg alloys than in Al-low Mg alloys. In Al-high Mg alloys strained with low strain rate, the serrated yielding due to the Portevin-Le Chatelier effect occurred concurrently with Luders strain. The pinning points inducing Luders strain were, for the most part, formed during furnace cooling at temperatures between 350-450 °C.