Fatigue Behaviour of Friction Stir Joined Aluminium Alloy NG5754 and AA6111 Sheets

A study examining the fatigue behaviour of spot friction stir joined (SFJ) aluminium NG5754 and AA6111 sheets was carried out. Different friction stir holding times were applied to the NG5754 alloy, whilst paint bake cycles were applied to the AA6111 joints in order to examine the effects of these variables on the fatigue behaviour of the joints. Static and fatigue tests were performed on all samples and the results were compared. It was demonstrated that the material flow characteristics were affected by the holding time leading to different joint attributes, which in turn contributed to different fatigue behaviour. Paint bake cycle affected the fatigue life, particularly at low applied loads.