CAJ | 학술논문

为进一步提高Mg-A1-RE基合金的力学性能,采用高压压铸技术制备Mg-3.0Al-1.8Ce-0.3Y-0.2Mn合金,并研究其微观组织、金属间相的热稳定性和合金的力学性能.结果表明:合金由细小的初生α-Mg枝晶和枝晶间的共晶组成.共晶中存在两种金属间相,即Al11(Ce,Y)3和Al2(Ce,Y),其中Al11(Ce,Y)3是主要增强相.研究还表明,Al11(Ce,Y)3的热稳定性是有条件限制的,在200℃时效800 h,它基本保持稳定,而在450℃时效800 h,绝大部分的Al11(Ce,Y)3发生相分解,转变为Al2(Ce,Y).添加Ce和Y后,合金强度在室温和200℃下得到明显的提高.合金性能的提高主要归因于Al11(Ce,V)3的形成对枝晶间区域的增强作用、晶粒细化的影响以及由Y原子造成的固溶强化.
위진일보제고Mg-A1-RE기합금적역학성능,채용고압압주기술제비Mg-3.0Al-1.8Ce-0.3Y-0.2Mn합금,병연구기미관조직、금속간상적열은정성화합금적역학성능.결과표명:합금유세소적초생α-Mg지정화지정간적공정조성.공정중존재량충금속간상,즉Al11(Ce,Y)3화Al2(Ce,Y),기중Al11(Ce,Y)3시주요증강상.연구환표명,Al11(Ce,Y)3적열은정성시유조건한제적,재200℃시효800 h,타기본보지은정,이재450℃시효800 h,절대부분적Al11(Ce,Y)3발생상분해,전변위Al2(Ce,Y).첨가Ce화Y후,합금강도재실온화200℃하득도명현적제고.합금성능적제고주요귀인우Al11(Ce,V)3적형성대지정간구역적증강작용、정립세화적영향이급유Y원자조성적고용강화.
With the aim to further improve the mechanical properties of Mg-Al-RE-based alloy,Mg-3.0Al-1.8Ce-0.3Y-0.2Mn alloy was prepared by high-pressure die-casting technique.The microstructure,thermal stability of intermetallic phases and mechanical properties were investigated.The results show that the alloy is composed of fine primary α-Mg dendrites and eutectic in the interdendritic regions.The intermetallic phases in eutectic are Al11(Ce,Y)3 and Al2(Ce,Y) with the former being the dominant one.The thermal stability of Al11(Ce,Y)3 is conditioned.It is basically stable at temperature up to 200 ℃ within 800 h,while most of the Al11(Ce,Y)3 intermetallics transform to Al2(Ce,Y) at higher temperature of 450 ℃ for 800 h.The alloy exhibits remarkably improved strength both at room temperature and 200 ℃,which is mainly attributed to the reinforcement of dendrite boundaries with Al11(Ce,Y)3 intermetallics,small dendritic arm spacing effect as well as the solid solution strengthening with Y element.