中文摘要：

利用自行研制的磁场发生器产生强交变磁场,采用对比试验的方法研究LY12硬铝合金磁处理前后组织的变化。应用耦合场理论采用数值分析的方法计算处于电磁热场中的LY12铝合金的磁场应力场及热应力场分布。结果表明,强交变磁处理可以使热塑性成形后的硬铝合金组织变得均匀、致密。在谐性磁场作用下,硬铝合金内部产生很大的涡旋电流,同时较大的磁致应力场引起的磁致震荡也会相当明显;热应力的存在又必然导致磁致震荡效应变得剧烈,更有利于微观组织脱离缠结,组织趋于致密化、均匀化。数值分析结果直观地为强交变磁处理改善金属组织提供了依据。

英文摘要：

The microstructure transformation of LY12 aluminum alloy before and after magnetic treatment was studied with a contrast method and by a self developed magnetic field generator to produce powerful alternating magnetic field. The magnetic force and thermal-stress distributions in LY12 alloy were respectively calculated by numerical simulation according to the coupling field theory. The results show that the powerful alternating magnetic treatment can make the mierostructure of the alloy after hot forming become evener and compacter. Under alternating magnetic field, a eddy current appears in the alloy and the magnetic vibrating from alternating magnetic force is very obvious. Existed thermal-stress accelerates the magnetic vibrating effect which is in favor of microstructure deviating from tangle, so the microstructure becomes evener and compacter. The numerical analysis results directly perceives for the powerful alternating magnetic treatment improving the metal microstructure.