High Cycle Fatigue Behavior and Microstructural Characterization of 6013-T4 Aluminum Alloy Laser Welded Joints

In this work the mechanical behavior of laser welded aluminum AA6013, subjected to post-welding heating treatments (PWHT), was investigated. A fiber laser with an average power of 1.5 kW was used to weld two 1.6mm thick sheets in T-joint configuration. After welding, the samples were subjected to distinct heat treatments. Hoop tensile tests made on sample heat treated at 190 degrees C for four hours show an increase of the tensile strength up 76 MPa, but the strain had decreased to 4%; the samples treated for two hours at 205 degrees C increased maximum strength to 65MPa, with a decrease in strain of 5%. In T-pull tensile tests, the tensile properties of as-welded and heat treated samples remained the same. Standard S-N curve showed that the welding reduced the number of cycles to failure, and the heat treatments do not affected fatigue properties.