Microstructures and Properties of Al₂O₃/Fe-28Al-5Cr Composites Prepared by Hot-Pressed Sintering

Fe-28Al-5Cr based composites were prepared by adding 10wt% and 20wt% Al2O3 ceramic particles into self-made Fe-28Al-5Cr alloy powders and following hot-pressed sintering, and the effects of Al2O3 content on microstructure, mechanical and high-temperature wear properties of the composites were studied. The results show that the relative density of the composites up to 99%, and the composites were composed of Fe3Al matrix and Al2O3 enhanced phase. Al2O3 mainly distributed at grain boundary of Fe3Al, which leaded to the formation of net-structured Al2O3 when Al2O3 adding contents reached to 20wt%. The strength of the composites was lower than that of the matrix, and it decreased with the increase of Al2O3 adding contents, but the high-temperature wear resistance of the composite with 20wt% Al2O3 was improved obviously comparing with that of the matrix.