Investigating the Friction Stir Processing Effect on the Fracture Behavior of 6061 Aluminum Alloy under Pure Shear Loading

Friction stir processing (FSP) is utilized in various industries due to its unique properties. In this regard, a better insight into the material properties obtained from this method will facilitate a broader application. One of the most important properties that should be well renowned before any use is how a material behaves when it has cracks. Crack growth under shear loading is one of the most significant factors in component failure, and if the material behavior after the FSP method in the presence of cracks is known, it is possible to use it safely. In this research, the influence of the FSP on the mechanical properties and resistance of the material against crack growth under pure shear loading has been investigated. It was found that this process significantly increases the strength and ductility so that the yield strength, ultimate tensile strength, and elongation-to-failure improve by about 42%, 67%, and 125%, respectively, compared to the initial state. It was also understood that the processed sample demonstrates an average drop of 23% in strength against crack growth compared to the initial state. It seems that due to FSP application, the amount of brittle fractured surfaces has been substantially increased, causing a decrease in the critical fracture parameter values.