Adiabatic Shear Banding in an Al-Mg-Si Alloy Processed by Equal Channel Angular Pressing

摘要

Equal channel angular pressing is an outstanding method for imposing large plastic deformation to metallic materials without any decreasing in cross section area of as processed samples. In this paper, the effect of working temperature, ram speed and the number of passes on the formation of adiabatic shear bands in A16061 during equal channel angular pressing was investigated. Billets of the alloy were processed up to four passes via route B_C from room temperature to 200°C with two ram speeds using a die that imparts an effective strain of ～1.1 per pass. The results have demonstrated that the onset of the adiabatic shear banding in this alloy strongly depends on the ram speed: more frequently observed at the higher ram speed than the lower speed. Although the geometry of the macroscopic view of shear band is similar in all cases, the development of bands depends on the number of passes as well as processing temperature.