Influence of forming process on three-dimensional morphology of TiB2 particles in Al-Ti-B alloys

A series of Al-Ti-B master alloys were prepared by different preparation routes, and the TiB2 particles in the master alloys were extracted and analyzed. It is found that the forming process has significant influence on the three-dimensional morphology of TiB2 particles. Different preparation routes result in different reaction forms, which accounts for the morphology variation of TiB2 particles. When the Al-Ti-B master alloy is prepared using “halide salt” route, TiB2 particles exhibit hexagonal platelet morphology and are independent with each other. In addition, the reaction temperature almost does not have influence on the morphology of TiB2 particles. However, TiB2 particles exhibit different morphologies at different reaction temperatures when the master alloys are prepared with Al-3B and Ti sponge. When the master alloy is prepared at 850 °C, a kind of TiB2 particle agglomeration forms with a size larger than 5 μm. The TiB2 particles change to layered stacking morphology even dendritic morphology with the reaction temperature reaching up to 1200 °C.