INFLUENCE OF HARDNESS OF THE COUNTERBODY IN 3-BODY ABRASIVE WEAR - AN OVERLOOKED HARDNESS EFFECT

The resistance to three-body abrasion of some common metals, mainly a tool steel and an aluminium alloy, both heat treated to different hardnesses, has been evaluated in two different tribosystems. The different materials have been tested against each other in different combinations to study the influence of the relative hardness of the two bodies on the wear rate in three-body abrasion. In all tests the abrasives have been much harder than the metals. It was observed that the wear rate of a solid body in three-body abrasion strongly depends on the hardness of the counterbody. In three-body abrasion a material may, under some circumstances, be most strongly worn if the counterbody is softer than the metal to be worn. This is because the abrasive particles can be embedded in the softer surface and groove the harder one. However, many parameters of the tribosystem influence the embedding of particles and the wear rate in three-body abrasion. It is shown that the size of the area in which the abrasives are embedded compared to the size of the wear scar in the counterbody as well as the smoothness of the surfaces are of importance.