An Investigation on Strength Deterioration of Aluminum Alloy Welded Joint under Thermal Cycling Conditions

Effects of thermal cycling on the tensile strength of aluminum alloy welded joints are studied experimentally in this paper. The damage mechanisms are also analyzed based on the microstructure observations. Results reveal that certain thermal cycling can cause strength decrease especially at the heat affected zone of the aluminum alloy welded joint. The cyclic temperature and the external load are the key factors which influence the strength of the welded joint specimens, while the cyclic period has a minor effect in thermal cycling conditions. Microstructure analysis also shows that voids nucleation and evolution governs the damage process under thermal cycling condition.