Al–7Si–5Cu/Al2O3–ZrO2 Laminated Composites with Excellent and Anisotropic Wear Resistance

Abstract

The authors prepare nacre‐mimetic Al−7Si−5Cu/Al2O3−ZrO2 composites with alternately arranged soft‐hard phases and different ceramic compositions using freeze casting and gas‐pressure infiltration techniques and investigate their dry abrasive wear resistance. These composites exhibit excellent and anisotropic wear resistance when worn along different directions. The wear rates of the composite with Al2O3:ZrO2 = 1:9 against 400‐grit, 240‐grit, and 100‐grit SiC sandpapers are approx. 1/78, 1/37, and 1/27 of those of the Al−7Si−5Cu alloy. The underlying mechanisms for the excellent wear resistance of these nacre‐mimetic composites are ascribed to the “self‐sharpen” effect in the early running‐in period and the formation of friction films in the later wear period. Moreover, the anisotropic wear resistance is interpreted by the different stress states that the interface is subjected to.