Squeeze Casting 에 의하여 제조된 Al2O3 / Al - Si 금속복합재료의 고온강도와 계면반응

Abstract

The tensile strength of squeeze cast 20% Al₂O₃, whisker reinforced Al-12% Si matrix composite was investigated in temperature range from room temperature to 500℃. The interfacial reaction and the variation of tensile strength in Al₂O₃,/Al- Si composite with the exposure time up to 192 hours at 300℃ and 500℃ were also investigated. The tensile strength of Al₂O₃/Al-Si composite decreases rapidly with increasing temperature above 200℃, however, the composite maintains 2∼3times higher tensile strength compared with the matrix above 300℃. The tensile strength of the composite decreases with increasing exposure time at 300℃ due to the decrease in tensile strength of Al-Si matrix. The tensile strength of the composite decreases with increasing exposure time at 500℃ due to the interfacial reaction in addition to the decrease in tensile strength of the matrix. When the composite is exposed at 500℃, the interfacial reaction is found to be proceeded at whisker/matrix interface and the reaction compounds of Mg(Al, Fe)₂O₄, MgAl₂O₄and Mg₃Al₂SiO₃O_(12) have been identified.