CAJ | 학술논문

为获得细小、圆整且分布均匀的半固态A356合金初生α相，向合金熔体中添加了不同含量的混合稀土La和Ce对合金进行变质处理，熔体经620℃浇注后，利用变频控制的电磁搅拌装置对熔体进行电磁搅拌15 s并使其在610℃保温10 min，观察并分析合金凝固组织中初生α相的形貌与尺寸。利用扫描电镜和能谱仪分析测定La和Ce在基体的分布情况，探讨混合稀土元素在电磁搅拌条件下对初生α相的细化机制。结果表明：La和Ce在电磁搅拌条件下易于均匀分布在初生α相周围，混合稀土元素La与Ce在短时弱电磁搅拌的条件下可以高效地细化半固态A356合金组织，稀土对半固态A356铝合金的初生α相细化机制与稀土在铝合金中产生的共晶反应有关。
위획득세소、원정차분포균균적반고태A356합금초생α상，향합금용체중첨가료불동함량적혼합희토La화Ce대합금진행변질처리，용체경620℃요주후，이용변빈공제적전자교반장치대용체진행전자교반15 s병사기재610℃보온10 min，관찰병분석합금응고조직중초생α상적형모여척촌。이용소묘전경화능보의분석측정La화Ce재기체적분포정황，탐토혼합희토원소재전자교반조건하대초생α상적세화궤제。결과표명：La화Ce재전자교반조건하역우균균분포재초생α상주위，혼합희토원소La여Ce재단시약전자교반적조건하가이고효지세화반고태A356합금조직，희토대반고태A356려합금적초생α상세화궤제여희토재려합금중산생적공정반응유관。
In order to obtain the fine, round and uniform distribution primary α phase in semisolid A356 alloy, the different amounts of mixed RE elements La and Ce were added into the alloy melt,and the melt was poured at 620℃and slightly electromagnetically stirred for 15 s with an electromagnetic stirrer controlled by frequency conversion, then, it was isothermally held at 615℃for 10 min. The morphology and size of the primaryαphase were analyzed, and the distributions of La and Ce were researched by SEM and EDS. The refinement mechanism of mixed RE under electromagnetic stirring was discussed. The results indicate that RE elements La and Ce are easy to uniformly distribute around the primaryαphase under electromagnetic stirring, and RE elements La and Ce can effectively refine the primaryαphase under the condition of short and weak electromagnetic stirring. The refining mechanism of RE on the primaryαphase in semisolid A356 alloy can be concerned with the eutectic reaction induced by RE in the alloy.