Fabrication of Al-TiB sub(2) Nanocomposites by Flux-Assisted Melt Stirring

The fabrication process for Al-TiB sub(2) nanocomposites, in which TiB sub(2) nanoparticles were incorporated into aluminum with K sub(2)ZrF sub(6) flux-assisted melt stirring, was studied. The microstructure of the Al-TiB sub(2) nanocomposites was investigated using scanning electron microscopy and transmission electron microscopy. The strengthening effect of TiB sub(2) nanoparticles on the aluminum matrix was examined by microhardness measurements. Results revealed that TiB sub(2) nanoparticles were successfully incorporated and dispersed into the aluminum melt in the presence of the K sub(2)ZrF sub(6) flux during mechanical stirring. In the as-cast microstructure, most nanoparticles segregated in the interdendritic regions as a result of particle redistribution during solidification. The addition of 2, 5, and 10 wt pct TiB sub(2) nanoparticles increased the composite hardness by 60, 90, and 150 pct, respectively, when compared to commercial purity aluminum. The role of K sub(2)ZrF sub(6) flux agent on the incorporation of nanoparticles into aluminum melt was discussed.