Deformation Behavior of Al-Ti-B Master Alloy during ECAP Process

Equal channel angular pressing(ECAP)was carried out on Al-Ti-B master alloy at room temperature.The effects of ECAP on distribution and grain size of the second-phase particles were analyzed with high temperature microscope and scanning electron microscope and the hardness of the material was measured by sclerometer after different ECAP passes.The results showed that the distribution of the second-phase particles was improved greatly and the grain size was remarkably refined by ECAP process.After 8 passes of ECAP in route Bc with the billet being rotated 90°clockwise,the second-phase particles were uniformly distributed in α-Al matrix and initial block-like particles with about 20 μm in length,10 μm in diameter turned to be granular with an average grain size of about 5 μm.After 1 pass,the hardness of the material increased significantly and the increasing trend became slower after 4 passes.