Wear properties of copper and copper composites powders consolidated by high-pressure torsion

The wear characteristics of Cu and Cu-SiC composite microsize powders consolidated by cold compaction combined with sintering or high-pressure torsion (HPT) were investigated. The HPT processed (HPTed) samples with bimodal and trimodal microstructures and fine Cu grains and SiC particle sizes have superior hardness, reasonable ductility level, and high wear resistance. The wear mass loss and coefficient of friction of HPTed samples were remarkably lower than that of cold-compacted and sintered samples as well as that of micro and nano Cu and Cu-SiC composites from previous studies. The sample fabrication method has an apparent influence on the wear mechanism. The wear mechanism was converted from adhesive, delamination, three-body mechanism, grooves (take off the SiC particles), and cracks into abrasive wear after HPT. Oxidization can be considered a dominant wear mechanism in all cases. The worn surface morphology and analysis support the relationship between wear mechanism and characteristics.