Fatigue behavior of AZ31B magnesium alloy electron beam welded joint based on infrared thermography

Fatigue behavior of AZ31B magnesium alloy electron beam welded joint undergoing cyclic loading was investigated by infrared thermography. Temperature evolution throughout a fatigue process was presented and the mechanism of heat generation was discussed. Fatigue limit of the welded joint was predicted and the fatigue damage was also assessed based on the evolution of the temperature and hotspot zone on the specimen surface during fatigue tests. The presented results show that infrared thermography can not only quickly predict the fatigue behavior of the welded joint, but also qualitatively identify the evolution of fatigue damage in real time. It is found that the predicted fatigue limit agrees well with the conventional S-N experimental results. The evolution of the temperature and hotspot zone on the specimen surface can be an effective fatigue damage indicator for effective evaluation of magnesium alloy electron beam welded joint.