Abstract
Al-V-B master alloy is promising for refining Al-Si alloys,yet its optimal composition with superior effi-cacy remains to be explored.In this work,the evolution of refining phases in the Al-10Si/Al-V-B system with different V∶B ratios was evaluated by thermodynamic calculations,based on which the Al-V-B refin-ers with V∶B =1∶1 and 5∶1 were designed.Refining trails demonstrated that they could significantly re-duce the grain size of Al-10Si (wt.％) alloy from 1736 to 184-245μm with industrial addition amount.De-tailed examinations results clarify that when V∶B ratio is 1∶1 the nucleation particle is (V,Al)B2,which has a VB2-AlB2 core-shell structure and therefore presents the nucleation capability as AlB2 particle.When V.∶B ratio is as high as 5∶1,the nucleation particle is pure VB2.Density functional theory (DFT) calculation indicates that (0001) VB2/(111) α-Al interface has the lowest interfacial energy such that highest nucleation potency among other types of diboride/α-Al interfaces under consideration.The outcomes of this work provide fundamental guidance to develop superior V-B based refiners for Al-Si alloys.
基金项目
National Natural Science Foundation of China(51871138)
Science and Technology Commission of Shanghai Municipality(19010500400)
"111"projects(D16002)
NETL
NSTL
维普
万方数据