Microstructural evolution and mechanical properties of ZrB 2 /6061Al nanocomposites processed by multi-pass friction stir processing

Microstructural evolution during multi-pass friction stir processing (FSP) of the as-cast ZrB2/6061Al nanocomposite and corresponding mechanical properties were investigated. The initial sample was characterized by primarily micrometer-sized clusters of ZrB2 nanoparticles within the coarse dendrites. Multi-pass FSP successively broke these clusters, refined the matrix grains and finally produced a thoroughly homogeneous microstructure in the...