Modification of Mg2Si in Mg-Si alloys with K2TiF6, KBF4 and KBF4 + K2TiF6

The modification effect of KBF4 on the primary and eutectic Mg2Si in Mg-Si alloy is better than that of K2TiF6. This may be the reason of the presence of B in melts. However, the modification effect of KBF4 is greatly weakened by the simultaneous addition of K2TiF6 due to the decreasing of B content in the melts by the formation of TiB and TiB2.