This study evaluated the mechanical properties and thermal properties of Al-12 vol％B4C composite at elevated temperature strengthened with in situ Al2O3 network.The composite was fabricated using powder metallurgy (PM) with raw materials of fine atomized aluminum powders,and the associated microstructures were observed.At 350 ℃,the composite had ultimate tensile strength of UTS =137 MPa,yield strength of YS0.2 =118 MPa,and elongation of ε=4％.Besides,the mechanical properties of the composite remained unchanged at 350 ℃ after the long holding periods up to 1000 h.The excellent mechanical properties and thermal stability at 350 ℃ were secured by in situ am-Al2O3 network that strengthened the grain boundaries.The interfacial debonding and brittle cracking of B4C particles were the main fracture mechanisms of the composite.In addition,the influence of sintering temperature and rolling deformation on the microstructures and mechanical properties was studied.