The Effect of Friction Stir Processing on the Microstructure and Mechanical Properties of an Aluminum Lithium Alloy

Friction stir processing (FSP) was conducted on a wrought plate of AA2099 to re. ne and homogenize the microstructure and enhance the through-thickness ductility and fracture resistance. Optical microscopy (OM), orientation imaging microscopy (OIM), and transmission electron microscopy (TEM) methods were employed to evaluate microstructure and microtexture in as-received material and in material subjected to FSP as well as postprocessing heat treatments. Hardness and orientation-dependent tensile test data were combined with anticlastic bending fatigue data to characterize the as-received, processed, and processed and heat-treated conditions of the material.