Abstract
The current study is concerned with the effect of friction stir welding (FSW) on the mechanical properties of aluminium alloy (AA1100). The FSW process was carried out using two rotational speed values—1100 rpm and 1500 rpm at a constant weld speed of 98 mm/min. The standard tensile and fracture (compact tension) specimens were prepared and subjected to mechanical tests to study the load–displacement behaviour and determine the fracture toughness of the FSW samples. In tensile tests, the ultimate tensile strength of the specimen was found to decrease by 12.6 and 31.8% at 1100 rpm and 1500 rpm, respectively. In the case of fracture tests, the estimated fracture toughness of the friction stir (FS) welded CT specimens was 97.24% for 1100 rpm and 85.62% for 1500 rpm, respectively, compared to the base metal specimen’s fracture toughness. In addition, the fractographic analysis of failures with SEM revealed two types of surface textures. Whilst the base material fractured surface was made up of rough surface textures with voids and dimples, the surfaces of the welded samples for both the rotational speeds were granular, with more pronounced peaks and valleys.
