High compressive strength in nacre-inspired Al-7Si-5Cu/Al2O3-ZrO2 composites at room and elevated temperatures by regulating interfacial reaction

摘要

Al-7Si-5Cu/Al2O3-ZrO2 composites with nacre-like structures were prepared via ice-templating and gas pressure infiltration techniques. The composites were subsequently heat-treated at 850 degrees C for 0, 30, 60, 90 and 120 min to regulate the interfacial reaction between Al and ZrO2. The yield of larger (Al1-m Si-m)(3)Zr and ZrSi2 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 degrees 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.