GPa级超高压下Mg-6Zn-1Y合金晶体形态及凝固组织分析  

Solidification Microstructures and Crystalline Morphologies of Mg-6Zn-Y Alloy Solidified Under GPa Level Super-High Pressure

作　　者：林小娉[1] 董允[1] 徐瑞[2] 郑润国[1] 焦世辉[1] 

机构地区：[1]东北大学,辽宁沈阳110819 [2]燕山大学,河北秦皇岛066004

出　　处：《稀有金属材料与工程》2013年第11期2309-2314,共6页Rare Metal Materials and Engineering

基　　金：河北省自然科学基金(E2010001398);辽宁省自然科学基金(301112063);东北大学秦皇岛分校科技支撑项目(XNK201305)

摘　　要：利用扫描电镜（SEM）并配合能谱（EDS）、XRD研究了超高压凝固下Mg-6Zn-1Y合金晶体形貌和凝固组织.结果表明：GPa超高压下凝固,随着凝固压力的增大,α-Mg晶体形态由1.03×0-9 GPa（常压）下的树枝晶→细树枝晶→柱状树枝晶→粒状“胞晶”的转变,固/液界面趋于稳定.1.03×10-9 GPa下实验合金的凝固组织由α-Mg相、I-Mg3Zn6Y和S-Mg43Zn4Y3相3相组成,2～6 GPa下实验合金的凝固组织由α-Mg、I-Mg3Zn6Y和S-Mg43Zn4Y3相和高Y含量的Mg-Zn-Y三元相4相组成.The crystalline morphology and the phase evolution of Mg-6Zn-Y alloy solidified under a super-high pressure were investigated by scanning electronic microscopy （SEM） coupled with the energy disperse spectrum （EDS） and the X-ray energy diffraction （XRD）.The results show that with the increase of solidification pressure,the crystalline morphology transition from a coarse equiaxed dendritic to a super-fine equiaxed dendritic,to a columnar dendritic,and to a granular ＂cellular＂ is observed in the microstructure,suggesting the solid/liquid interface is stable.The microstructure of the alloy solidified under 10-9 GPa consists of three phases,i.e.α-Mg phase,I-Mg3Zn6Y phases and S-Mg43Zn4Y3 phase,while the microstructure of the alloy solidified under 2～6 GPa consists of four phases,i.e.α-Mg phase,I-Mg3Zn6Y phase,S-Mg43Zn4Y3 phase,and ternary Mg-Zn-Y phase with high Y content.

关 键 词：GPa级超高压 Mg-6Zn-1Y合金 晶体形态 凝固组织 

分 类 号：TG27[金属学及工艺—铸造]