Fatigue deformation characteristic of as-extruded AM30 magnesium alloy

The fatigue deformation behavior of as-extruded AM30 magnesium alloy has been investigated under different strain amplitudes in this paper, and the microstructure and fractograph during the cyclic deformation have been analyzed by use of the optical microscope (OM) and the scanning electronic microscope (SEM). The results show that there are many {1 0 –1 2} twins in the fatigue specimens of the extruded AM30 alloy, and with the increase of total strain amplitude, the twins become coarser and longer. Otherwise, there are many twin bands composed of many tiny lenticular type twins ({1 0 –1 2}〈1 0 –1 1〉 twin) near the fatigue fracture, which become more with increase of total strain amplitude.