Friction and wear of Aluminum considering surface movement in environment

Abstract

Aluminum (Al) waste is becoming a major ecological problem. Therefore, Al surfaces with shorter natural degradation times are less detrimental to the environment. Most studies account only for chemical degradation of Al. However, it is also important to consider tribological factors possibly influencing Al erosion, such as wind dust, soil movement, water/ice streams etc. Wear and friction of 1050A, 3003, 5005 and 6082 alloys was studied by using 1 to 10 N loads to represent tribological regimes, which can be significant under environmental conditions. Despite somewhat lower friction, Mg-rich 5005 wear rates were much higher than those of other alloys. This observation held true after the surfaces were anodized using hard (Type III) method with 60 µm thick layer of Al2O3 formed in the electrolyte of sulfuric and oxalic acids. Although wear resistance improved many times due to anodization, the profilometry demonstrated that wear in anodized 5005 was still much faster, while 3003 was the slowest. The velocity variation from 0.5 to 4 cm/s did not have much effect. The findings show that it is important to consider wear patterns of Al alloys when producing cans, foils and other waste-bound products in order to facilitate their faster natural degradation in environment.