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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. This paper presents the structures and wear properties of nacre‐inspired Al–7Si–5Cu/Al2O3–ZrO2 composites. The composites exhibit excellent wear resistance but distinct anisotropy when they are worn along different directions. The excellent wear resistance is ascribed to "self‐sharpen" effect and formation of friction films, while the anisotropy to the different stress states that the metal‐ceramic interface is subjected to. [ABSTRACT FROM AUTHOR]

In the present study, Mg-6Zn-1Zr (ZK60) alloy with a homogeneous fine-grained structure (~5 µm) was produced by hot extrusion. The influence of temperature on tensile properties anisotropy and the associated change in deformation mechanisms in the range of 25–275 °C of the fine-grained ZK60 alloy were investigated. Under room temperature, the fine-grained ZK60 alloy exhibited a high tensile strength of ~269–327 MPa and high ductility of ~15–39% when tested at three different directions, indicating a high anisotropy. With increasing testing temperature to 150 °C and further to 275 °C, the alloy showed a gradual decrease in anisotropy. Especially, the fine-grained ZK60 alloy exhibited superplasticity of ~376–434% when tested at 275 °C, which should be due to the increasing role of grain boundary sliding (GBS), as the strong basal texture associated with room temperature deformation became almost random at elevated temperatures. Moreover, the abrupt decrease in tensile anisotropy and associated change in texture with increasing temperature correlates closely to the transformation of deformation mode from a dislocation-dominated behavior to a GBS-mediated one. [ABSTRACT FROM AUTHOR]

Schmid factors (m) for typical slip modes (basal 〈a〉, prismatic 〈a〉, pyramidal 〈a〉 and 〈c + a〉 slips) and twinning patterns ( and twins) were systematically calculated in hexagonal close-packed Cd, Zn, Mg, Zr, Ti and Be. A monotonic effect on m-values was presented for pyramidal 〈a〉 and 〈c + a〉 slips, and and twinning patterns with decreasing c/a ratio. The results calculated herein were used to characterize deformation behaviors and provide essential data for anisotropic feature analysis. [ABSTRACT FROM AUTHOR]