High compressive strength in nacre-inspired Al−7Si−5Cu/Al 2 O 3 –ZrO 2 composites at room and elevated temperatures by regulating interfacial reaction

Abstract Al−7Si−5Cu/Al 2 O 3 −ZrO 2 composites with nacre-like structures were prepared via ice-templating and gas pressure infiltration techniques. The composites were subsequently heat-treated at 850 °C for 0, 30, 60, 90 and 120 min to regulate the interfacial reaction between Al and ZrO 2 . The yield of larger (Al 1−m , Si m ) 3 Zr and ZrSi 2 phases increased with longer dwell times. The compressive strength initially increased and then decreased. The highest strength was observed in composites treated for 60 min and reached 1600±40, 1261±30 and 1033±22 MPa at temperatures of 20, 150 and 300 °C, respectively. These values increased by 30−40% as compared to those of the non-treated counterparts and were 2-, 5- and 12-fold more than those of the matrix alloy, respectively, which is demonstrative of the material's excellent load-bearing capacity, particularly at elevated temperatures.