Development of grain structure during friction-stir welding of Cu–30Zn brass

High-resolution electron backscatter diffraction was employed to study the evolution of microstructure during friction stir welding of a typical low stacking fault energy material (Cu–30Zn brass) over a wide range of welding temperatures. In all cases, microstructure evolution was found to be governed by discontinuous recrystallization that occurred via grain-boundary bulging and subsequent recrystallization nucleation. This promoted drastic grain refinement and significant strengthening. The crystallographic textures that evolved were typically dominated by a A/A¯{111}<100> simple shear texture.