Fatigue behavior of friction plug welds in 2195 Al–Li alloy

The focus of this paper will be on the fatigue behavior of friction stir welded 2195 Al–Li plates that contain friction plug welds. Tensile tests were performed for specimens containing base metal, friction stir welded 2195-T8, and friction stir welded 2195-T8 containing a friction plug weld consisting of a 2195-T8 plug. The ultimate strength was determined for base metal, friction stir welded material, and friction plug welded material. Fatigue properties were determined for both the friction stir weld and friction plug welded specimens in the medium to high cycle regimes. Comparison of the results show that the friction plug weld reduced both the UTS and fatigue life as compared to specimens containing only friction stir weld. The reduction in fatigue life is most likely due to the complication of weld geometry, interacting heat affected zones, and strength mismatch between base metal, friction stir weld, and plug material.

► Friction stir welding (FSW) and friction plug welding (FPW) were studied.
► Fatigue and strength behavior of FSW 2195-T8 and FPW 2195-T8 was determined.
► FSW resulted in an under-matched joint with 68% of the strength of the base metal.
► FPW resulted in an under-matched joint with 57% of the strength of the base metal.
► S–N data FPW and FSW joints are presented.