Pin-on-disk wear behavior in a like-on-like configuration in a biological environment of high carbon cast and low carbon forged Co-29Cr-6Mo alloys

In order to examine the effects of carbides and microstructures on the wear behavior of a biomedical Co-Cr-Mo alloy in Hanks solution, the wear behavior of a forged Co-Cr-Mo alloy without addition of Ni and C (hereafter designated the forged CoCr alloy) and a high carbon cast CoCr alloy (hereafter designated the cast CoCr alloy) sliding against themselves have been investigated using a pin-on-disk type wear testing machine. The wear loss of the forged CoCr alloy was found to be much smaller than that of the cast CoCr alloy. Carbide precipitation in the coarse-grained structure of the cast CoCr alloy would account for the higher abrasive wear loss. The forged CoCr alloy, with no carbide and a refined grain size, which is more prone to strain-induced martensitic transformation, would exhibit excellent like-on-like wear resistance, mostly against surface fatigue wear, compared to the carbide-hardened cast CoCr alloy. (c) 2006 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.