Fabrication of Al alloy matrix composite reinforced with subsive-sized Al 2O 3 particles by the in situ displacement reaction using high-energy ball-milled powder

Abstract

High-energy mechanical milling (HEMM) and sintering were employed to fabricate an Al alloy matrix composite reinforced with subsive-sized Al 2O 3 particles. Al–(Mg, Cu, Si)–SiO 2, composite powders were prepared by HEMM. Nano-sized SiO 2 particles embedded in Al–(Mg, Cu, Si) matrix particles were obtained by HEMM. Al-based metal matrix composite reinforced with subsive-sized Al 2O 3 particles was fabricated successfully by sintering at 650 and 750 °C for 2 h using milled powder. Subsive-sized Al 2O 3 particles and eutectic Si were formed by in situ displacement reaction between Al and SiO 2 during sintering, and homogeneously distributed in the Al–Si–(Mg, Cu) matrix. The flexural strength of the sintered specimen (1.2 GPa) using 8 h milled powder was about four times as the sintered specimen using as-mixed powder.