Peening effects on mechanical properties in friction stir welded AA 2195 at elevated and cryogenic temperatures

The shot peening and laser peening effects on the mechanical properties of friction stir welded 2195 aluminum alloy were investigated at elevated and cryogenic temperatures. The tensile properties were evaluated at different regions of the weld using a digital image correlation (DIC) system and mini-tensile testing samples. The surface and through thickness residual stresses were also obtained by using X-ray diffraction and the contour method. The specimens processed using laser peening exhibited superior mechanical properties for both elevated and cryogenic temperatures. Moreover, an electron backscattered Kikuchi diffractometry (EBSD) technique indicated a decrease in surface grain size for the laser peened samples when compared to the as welded condition.