强磁场下Al-Si过共晶合金组织细化原理研究  

Principle of hypereutectic Al-Si grain refinement under high magnetic field

作　　者：张维平[1] 袁聪[1] 

机构地区：[1]大连理工大学材料科学与工程学院,辽宁大连116023

出　　处：《材料科学与工艺》2007年第5期670-672,共3页Materials Science and Technology

基　　金：国家自然科学基金资助项目(59701001).

摘　　要：为了改善Al-Si合金性能,研究了强磁场对Al-Si过共晶合金组织的影响.依据热力学和晶粒形核理论,阐述了组织变化的原因.研究表明:当Al-Si过共晶合金在600℃施加强磁场并平行于磁场方向下凝固时,共晶组织被细化,但对初生硅相影响不大;磁场强度越大,细化效果越明显;强磁场降低了固态熵和磁自由能的影响,使共晶组织临界形核半径减小,而硅由于是逆磁质对其影响不大;强磁场使液态金属平行于磁场方向流动,进一步细化了组织.In order to improve the performance of the A1 - Si alloy, the effect of high magnetic field on the hy- pereutectic A1 - Si alloy structure was researched. Based on the thermodynamics and grain nucleating theory, the reason of the structure changing was explained. The results showed that when the hypereutectic A1 - Sial- loy solidified in the parallel direction of the high magnetic field in 600 ℃, the eutectic structure was refined, but it had no effect on the primary Si; The effect would be the more obvious with the more intense magnetic field. The intense magnetic field reduced the effect of the solid state entropy and the magnetic free energy, and reduced the critical nucleation radius of the eutectic structure, but it had no effect on Si because of its diamag netic property. High magnetic field made the liquid metal fluent in the direction of the magnetic field, which refined the structure further.

关 键 词：强磁场 组织 磁化能 

分 类 号：TG665[金属学及工艺—金属切削加工及机床]