Mechanical properties and microstructures of ultrafine-grained pure aluminum by asymmetric rolling

  The mechanical properties and microstructures of both symmetrically and asymmetrically rolled Al were investigated. The yield strength was substantially increased by an improved asymmetric rolling (ASR) process. Nearly equiaxed ultrafined grains with an average size less than 1 μm were obtained through the improved ASR with a reduction of 90%. The microstructure was homogeneous and high-angle boundaries were predominant. The results indicate that this ASR process can be considered as one of most the effective severe plastic deformation methods.