ABSTRACT
Friction stir processing (FSP) has emerged as a promising technique and demonstrated the tremendous potential to enhance several properties in the field of surface engineering. Similar to friction stir welding, FSP is a solid-state processing technique which uses a non-consumable tool. The plasticized material is stirred as per the rotation of the FSP tool, and due to recrystallization, new grains and grain boundaries are evolved. Heat is generated due to two basic reasons during FSP which are friction between FSP tool and the workpiece and plastic deformation of the material. In FSP, the tool plays a crucial role in performing three functions, which are heating the workpiece, causing material flow, and holding the plasticized material beneath the tool shoulder. The dimensions of the pin, shoulder diameter to pin diameter ratio and the profile of the pin are the important elements in designing an FSP tool pin.
