Controlled grain size distribution and refinement of an EN AW-6082 aluminium alloy

An EN AW-6082 aluminium alloy was subjected to an incremental deformation by a new process named gradation rolling. The process is used to generate a grain size distribution in a rod shaped billet. A gradient of the grain size from coarse grained to ultrafine grained size is obtained by gradation rolling. The microstructure shows an increasing grain refinement related to the true strain. This results in strain-hardening and grain-boundary strengthening in the surface region (130 HV0.5). as compared to the unchanged core (110 HV0.5).