Development of ultra fine grained structure (UFG) on AA6061 and reinforced with CuO composite through equal channel angular pressing (ECAP) process

The purpose of this investigation is to fabricate the aluminium matrix composite and develop Ultra Fine Grained Structure. Aluminum matrix composites are widely used in the aerospace application for their outstanding properties. Equal Channel Angular Pressing (ECAP) is a process for obtaining ultrafine grained materials (UFG) without any change in their cross section. The composite produced billets are pressed in the L-shaped (90 degrees angle) die with 25 ton high pressure to fabricate ultra-fine grained structure. In order to avoid cracking of the ECAP samples through ECAP process, it is necessary to do the solution heat treatment at 530 degrees C for 4hr before pressing after that the samples are quenched at room temperature water then immediately pressed. The ultra-fine structured grains formed are of granular type containing high angle grain boundaries. In this work, AA6061 was used as matrix and cupric oxide was used as reinforcement to prepare composite with stir casting process. Grain size reduction is observed in the microstructure the grain size is measured with image analyzer. ECA pressed age hardened samples have shown remarkable increase in hardness also.