Effect of (ti + V)B2 on the Grain Structure of Al–7Si Alloy

A new refiner containing (Ti + V)B2 phase was prepared in this study. It consists of a special VB2–TiB2 core–shell structure, and the size of most (Ti + V)B2 granular phase is between 100 and 500 nm. Considering Al–7Si alloy as the research object, the refining ability of Al–Ti–B, Al–V–B, and Al–(Ti + V)–B was compared under the condition of same content of added B. The grain refiner containing (Ti + V)B2 can significantly reduce the grain size of Al–7Si. Al–(Ti + V)–B refines the as-cast grain size from 854.6 ± 28 to 136.93 ± 2.45 μm, which is better than the results obtained for Al–Ti–B- and Al–V–B-based refiners.