镁合金具有比强度高、比刚度高、质量轻、切削性能好等优点,在航空航天、汽车制造及医疗服务等领域有着广泛的应用前景,但其绝对强度低,塑性差,限制了镁合金在一些领域的应用.为了改善镁合金综合性能,研究发现在镁合金中按一定比例加入稀土元素与过渡族元素后,会出现一种长周期有序堆垛结构(Long Period Stacking Ordered,简称LPSO相),LPSO相具有高硬度、高抗蠕变性能、高弹性模量等优点,能够同时改善合金的强度和塑性,因此,LPSO相引起了广大研究人员的关注.本文综述了稀土镁合金中LPSO相的研究进展,全面分析了 LPSO相的类型及原子排布,讨论了 LPSO相的形成机制和规律,以及LPSO相对合金性能的影响机制,评述了通过第一性原理对LPSO相晶体结构、弹性模量和LPSO相与层错能间关系的研究,最后对含LPSO相稀土镁合金的未来发展做出展望.
Research Progress of LPSO Phase in Rare Earth Magnesium Alloy
Magnesium alloy has many advantages,such as high specific strength,high specific stiffness,light weight and high machinability,etc.It has a wide application prospect in aerospace,automobile manufacturing and medical services,but its low absolute strength and poor plasticity limit its application in some fields.In or-der to improve the comprehensive properties of magnesium alloys,it is found that after adding rare earth ele-ments and transition group elements in a certain proportion,a long period stacking ordered structure(LPSO phase)will appear.LPSO phase has the advantages of high hardness,high creep resistance and high elastic modulus,which can simultaneously improve the strength and plasticity of the alloys.Therefore,LPSO phase has attracted the attention of researchers.In this paper,the research progress of LPSO phase in rare earth magne-sium alloys is reviewed,the types and atomic arrangement of LPSO phase are comprehensively analyzed,the formation mechanism and law of LPSO phase and the influence mechanism of LPSO phase on alloy properties are discussed,and the first-principles research on the crystal structure,elastic modulus and the relationship be-tween LPSO phase and stacking fault energy of LPSO phase is reviewed.Finally,we prospect the future develop-ment of rare earth magnesium alloys containing LPSO phase.
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