Investigation on microstructures and interface character of B4C particles reinforced 2024Al matrix composites fabricated by mechanical alloying

The microstructure and interface of B4C particulate reinforced 2024 aluminum alloy matrix composites produced by mechanical alloying and hot extrusion were investigated. The results showed that the B4C particles could be dispersed into based alloy uniformly by high-energy milling technique. The twin structure of B4C particle was detected frequently in this experiment. A refined microstructure of matrix was obtained with size of sub-grains about 400 nm. EDX, TEM and SAD analysis indicated that the MgO particles were formed near the interface during fabrication. The temperature increment during high-energy milling was attributed to the formation of B2O3 which promoting generation of MgO particles during hot consolidation processing.