Grain size affecting the deformation characteristics via micro-injection upsetting

The micro-injection upsetting (MIU) experiments of commercially pure aluminium have been conducted on two groups specimens with different grain structures. One group is coarse (CG, undeformed) and the other fine (FG) achieved via 4th pass equal channel angular pressing in micro-meso/scale. were further processed by micro/meso-scale extrusion before conducting MIU for fabricating tiny pins. Micro-upsetting test pins showed that material has a good isotropic flow forming free undesirable defects comparing CG counterparts, which can be ascribed to decreasing boundary strengthening effect case FG structure.