Wear resistance of hard anodic coatings fabricated on 5005 and 6061 aluminum alloys

The wear resistance of hard anodic coatings fabricated on 5005 and 6061 aluminum alloys was determined. The Taber abrasion test, ball-on-disc tribological test, and scratch test at constant load were conducted. The wear resistance of the hard coating fabricated on the 6061 alloy was found to be higher compared to the coating on the 5005 alloy. This is related to the lower nanoscale porosity of the former, and the higher hardness of the 6061 alloy compared to 5005. The specific wear rates for the load of 4.905 N were equal to 1.70 x 10-5 and 1.02 x 10-5 mm3 N-1 m-1 for the coatings on 5005 alloy and 6061 alloy, respectively. In the case of the hard anodized 5005 alloy, the specific wear rate increased with increasing load to 4.56 x 10-5 mm3 N-1 m-1 whereas for anodized 6061 alloy to 1.98 x 10-5 mm3 N-1 m-1. It was also found that the protective properties of the coating on 6061 alloy do not change significantly across the coating thickness.