SLIDING WEAR BEHAVIOR OF DEFORMATION-PROCESSED CU-15VOL.PERCENT-CR IN-SITU COMPOSITES

A deformation-processed Cu-15vol.%Cr in situ composite was made by con sumable arc melting and casting followed by extensive deformation. A s uperior combination of mechanical strength and electrical/thermal cond uctivity was achieved with the composite since Cr filaments existed in the nearly pure copper matrix. The effects of sliding speed and norma l pressure on sliding wear behavior and microstructure of the composit e were investigated, with a composite pin rubbing against a hardened A ISI 52100 steel disk on a pin-on-disk wear tester. In the studied rang e of normal pressure and sliding speed, the wear rate increased with i ncreased normal pressure, whereas the wear rate decreased with increas ed sliding speed. Sliding-induced subsurface deformation occurred not only in the sliding direction but also in the lateral directions perpe ndicular to the sliding direction. This lateral flow produced a twisti ng of the Cr filaments. The complex deformation mode was revealed clea rly by the morphological change of the ribbon-like filaments, Both con stituents of the composite were cooperatively deformed. The thickness of deformed subsurface layer increased with increasing normal pressure and sliding speed. Scanning electron micrographs showed plastic defor mation flow on the wear surface.