Bulk Al Matrix Nanocomposites Formed through In situ Oxidation and Melting of Aluminum Nanoparticles

摘要

The mechanical properties of Al alloys can be effectively enhanced with an addition of a low volume fraction of nano-sized reinforcements for numerous applications. However, it remains a great challenge for liquid processing of bulk Al matrix nanocomposites, which would be more economical than solid state processing methods. Here we report a novel fabrication method for bulk Al_2O_3 reinforced Al matrix nanocomposites through in situ oxidation and melting of Al nanoparticles. Al nanoparticles were first compressed into bulk pellets and then melted at 700°C under a protective atmosphere. During the processing thin Al_2O_3 films and nanoparticles were formed in situ and re-distributed into the Al matrix. The microhardness of the bulk Al matrix nanocomposite is about three times as high as that of pure bulk aluminum. This simple method has great potentials for an economical fabrication of high performance bulk Al_2O_3 reinforced Al matrix nanocomposites.