Abrasive tests of anodized coatings on alumiunm alloys were studied with lubricating oil, (wet) and no that (dry).
It was found that the amount of wear increased with larger abrasive grain and greater load on the wheel, and that wear greater in the wet tests; that is to say, the oil functioned as a grainding agent, increasing grindability. With smaller grain and lighter load, however, the difference in wear between the wet and dry tests was reduced very few and certain conditions the difference in wear was reversed; that is to say, the oil exhibited a lubricating action.