摘要
利用金相显微镜、扫描电镜、能谱分析、X射线衍射分析和室温拉伸试验研究了微量稀土Er对ZM5镁合金铸态组织和室温力学性能的影响。结果表明0.2%～0.6%稀土Er可细化ZM5镁合金的第二相,其形貌由连续粗大的树枝状分布转变为弥散均匀的颗粒状分布;合金中α-Mg枝晶随Er添加量的提高逐渐粗大,α-Mg枝晶长度增加,初生α-Mg相形貌也逐渐由等轴晶转变为粗大的树枝晶。当Er添加量为0.6%时,组织中有Al3Er相生成。Er的添加使合金室温力学性能下降,α-Mg枝晶粗大是合金力学性能下降的主要原因。
The effects of tiny Er on the microstructure and mechanical properties of ZM5 alloy were examined by OM,SEM,EDS and XRD,room temperature tensile test.The results show that with trace addition of Er,the secondary phase in the alloy can be refined and the morphology turns from thick dendrimer into disperse grain.As the addition quantity of Er increases from 0.2%-0.6%,the Mg17Al12phrase in the alloy can be refined and its morphology turns from thick dendrimer into disperse grain.The size of 琢-Mg dendrite structure gradually increases with the increase of addition quantity of Er.The first dendrites of 琢-Mg dendrite structure gets longer.The dendrite morphology of primary 琢-Mg phase turns from fine equiaxed grain into developed dendrite crystals.A new phase of Al3Er is found in the alloy with 0.6% Er addition.With the addition of Er,the tensile strength and elongation of the alloy decreases.The coarsening of 琢-Mg dendrite is the reason for the decline of mechanical properties.
出处
《热加工工艺》
CSCD
北大核心
2013年第24期73-76,80,共5页
Hot Working Technology
基金
国家自然科学基金资助项目(51101084)
江西省科技支撑计划项目(2009BHB15500)
