Dry wear behavior of the rheo-casting Al-16Si-4Cu-0.5Mg alloy was investigated by micro-scratch and dry sliding weartests. Analyses of the microstructure, scratch grooves, wear tracks, worn surfaces and wear debris of the alloy were carried out byoptical microscope and scanning electron microscope. The microstructural analysis showed that via rheo-processing, the primary Siwas refined and rounded, eutectics dispersed more homogenously, and even the skeleton AlFeMnSi phase was fragmented into facetshape. Micro-scratch test showed that the microstructural refinement resulted in better wear resistance. Dry sliding wear test revealedthat the rheo-processed sample exhibit obviously superior wear resistance because of the microstructure improvement. The dominantmechanism in mild wear condition is abrasion, but it turned to adhesion and oxidation in high applied load and fast sliding velocityconditions.
