The influences of ECAP on the dry sliding wear behaviour of AA7075 aluminium alloy

The coefficient of friction and specific wear rate of the AA7075 alloy increased with ECAP despite of the enhanced hardness. The visualization of the complete wear track highlighted the peaks and valleys formed during the dry sliding and the depth of the wear tracks and volume loss increased with ECAP. The dominant wear mechanisms varied depending on the ECAP. Material pileup with smearing and adhesion mechanisms were predominant for the homogenized specimen whereas the oxidation of wear tracks and progressive breakdown of oxide layer led to the three-body abrasion caused by formed oxide particles. The variation of dominant wear mechanisms surpassed the enhanced mechanical properties obtained with ECAP and diminished the wear resistance of ECAP processed AA7075 alloy.