Refinement of TiB_2 in Al-Ti-B Grain Refiner Alloys by Ultrasound and the Effect on Al Grain Size

摘要

High-intensity ultrasound was applied during the preparation of an Al-5Ti-1B master alloy when reacting fluoride salts with molten Al. The reaction rate was significantly increased with TiB_2 particles of much reduced mean diameter and narrow width spread produced in ～4 minutes. The improved grain refining performance of the TiB_2 in a commercial purity Al was studied and modelled using free growth model. The increased number and reduced size of TiB_2 particles provided an enhanced grain refining capability.