Investigation on the impact of parameters of FSW on microstructural transitions and the strength of CDA 101 joints

Abstact An experimental endeavor was made to fathom the influence of employed parameters on the microstructural transitions and tensile strength of friction stir welded (FSW) joints of CDA 101 Cu alloy. This investigation also aimed at providing insight into the interdependency between the mechanical properties and transformed microstructures. Flat plates of CDA 101 alloy were joined using the FSW process by employing four distinctive speeds of traverse and rotation. Employment of 1500 rpm in combination with 25 mm/min proved to be an exceptional combination, as the zone of nugget of this joint exhibited very fine sized, dynamically recrystallized, exquisite grain structures distributed consistently in equal spaces. A maximum tensile strength of 205.79 MPa was exhibited by this joint. It was confirmed that the employed speed of rotation of 1500 rpm was responsible for the generation of the ideal amount of frictional heat and the employed speed of traverse of 25 mm/min played a vital role in permitting the tool to traverse over the regions of the line of joint for a sufficient time period. Moreover, scanning electron microscopy fractography revealed that this joint exhibited smaller voids and has failed in a purely dimple mode of fracture, indicating the higher ductility of this joint.