Adhesion transfer layer formation in sliding on equal-channel angle pressed ultrafine grained AA6063

The effect of equal-channel angle pressing (ECAP) conditions on wear resistance and adhesion of the resulted ultrafine grained AA6063 in sliding against a steel ball has been investigated. Using the 3D laser confocal microscopy the parameters of wear and adhesion transfer layer thickness on ultrafine grained AA6063 has been measured. As it was established, the ECAP at room temperature allowed forming AA6063 microstructure in sliding, which is more wear resistant and less prone to adhesion as compared to the previous one at higher temperatures. The effect of ECAP pass number n on the above parameters becomes negligible for n > 8. The wear resistance of AA6063 processed by ECAP at 200°C is improved only for n = 4 whereas n > 4 has only a negative effect.