부산대학교 도서관

Friction stir tailor-welded blanks are often used in the production of complex-shaped components such as structural and automotive parts for their improved forming limits, uniform strain distribution throughout the component and material savings. Despite having such crucial impact, detailed investigation on the formability of friction stir-welded blanks is limited. This study investigated the impact of different weld parameters upon the mechanical properties and formability of friction stir-welded AA5754 sheets and correlating them with microstructure and texture studies. The tensile and hardness test results were explained based on weld quality at each parameter combination. To assess the formability, limit dome height tests were performed at different strain paths, and it was revealed that the minor strain of the welded specimens was poor in the biaxial region. Texture studies confirmed that the Goss texture component was either weak or completely diminished in the case of the biaxial strain path of deformed welded specimens leading to less minor strain in the biaxial region. The combinations of grain average misorientation, kernel average misorientation, grain orientation spread, and high-angle grain boundary fractions determined from EBSD studies showed the correlation for the effect of different weld parameters on mechanical properties and formability of friction stir-welded AA5754 sheets.