【摘要】 研究了Sb对Mg-4Al-4Si(AS44)镁合金显微组织和力学性能的影响。结果表明,未加Sb时,铸态AS44合金主要由α-Mg基体、β-Mg17Al12相和Mg2Si相组成,Mg2Si相呈粗大的骨骼状、块状和汉字状3种形态;加入少量的Sb(0.25%~1.25%)能有效细化Mg2Si相,并在合金中形成高熔点和较为弥散分布的Mg3Sb2相。随Sb含量的增加,Mg2Si相形貌发生显著变化,从粗大的骨骼状逐渐转变为块状和汉字状,当Sb含量达到1.25 wt%时,几乎全部转变为较细小的汉字状Mg2Si相颗粒。随着组织的改善,合金的抗拉强度、屈服强度和伸长率均得到不同程度的提高。更多还原

【Abstract】 The effects of Sb on the microstructure and mechanical properties of Mg-4Al-4Si (AS44) alloys were studied.The results show that the microstructure of as-cast AS44 alloy consists of α-Mg matrix,β-Mg17Al12 phase and Mg2Si phase before adding Sb.The phase Mg2Si exists in three different morphologies,namely the coarse skeleton-like,massive and the Chinese script type.The Mg2Si phase particles can obviously be refined after adding (0.25 wt%-1.25 wt%)Sb in Mg-4Al-4Si alloy,as well as a new phase with high melting-point Mg3Sb2 is formed,which is dispersed in the matrix.The morphology of Mg2Si particle in as-cast AS44 alloy changes from coarse skeleton-like to fine Chinese script-like mostly with the increase of the content of Sb up to 1.25%.The ultimate tensile strength,yield strength and elongation are also increased by refine microstructures.更多还原