稀土ce对mg-11li-3al合金组织及力学性能影响.doc

0本科学生毕业论文稀土 Ce 对 Mg-11Li-3Al 合金组织及力学性能影响黑龙江工程学院本科生毕业论文The Graduation Thesis for Bachelor's DegreeCe impact on Mg-11Li-3Al alloy microstructure and mechanical properties黑龙江工程学院本科生毕业论文I摘 要本论文针对广泛应用的镁锂合金，通过添加稀土铈来考察 Ce 对 Mg-11Li-3Al 镁合金组织和性能的影响，从而使镁锂合金获得更大的发展空间由于大部分镁合金的热导率和体收缩率较大，且合金液凝固时的结晶温度范围较宽，因此注定具有明显的晶粒粗化倾向，易产生疏松、缩孔和热裂等缺陷，严重的影响镁合金的加工成型性能，因此本课题采用氩气保护的真空熔炉法制备合金获得了较为准确的 Mg-11Li-3Al 合金的成分含量，为以后进一步实验做好了铺垫，并通过金相分析和力学性能测试，发现 Ce 在 Mg-Li-Al 系合金中以 Al2Ce 稀土化合物的形式存在，并且稀土 Ce 对 Mg-Li-Al 系合金有细化作用，随着稀土 Ce 加入量增加，合金中 Al2Ce 稀土化合物量也在增加，合金的力学性能先是提高，当到达一定量之后转而下降，最终确定当稀土 Ce 加入量为 1%时，其综合性能最佳。

关键词：镁锂合金；合金组织；热导率；收缩率；金相组织；力学性能黑龙江工程学院本科生毕业论文II黑龙江工程学院本科生毕业论文IIIABSTRACTThis thesis focuses on the widely used Mg-Li alloy by adding rare earth cerium to examine the Ce of Mg-11Li-3Al magnesium alloy and performance, so that the Mg-Li alloy for greater space for development.Most of the magnesium alloy thermal conductivity and volumetric shrinkage rate, and a wide range of crystallization temperature and the alloy solidified, and therefore destined to have a significant tendency of grain coarsening, and easy to produce loose, cratering and thermal cracking and other defectsserious impact on the processing of magnesium alloy formability, so the subject of argon gas protected vacuum furnace was prepared alloys. To obtain a more accurate Mg-11Li-3Al alloy ingredients and prepared the way for the future to further experiments, by metallographic analysis and mechanical testing and found that the rare-earth compounds of Ce in Mg-Li-Al alloy to Al2Ce form, and Ce on the refining effect of Mg-Li-Al alloy, with the increased amount of Ce, in Al2Ce rare earth compounds are also increasing the alloy, the mechanical properties of the alloy is first, when after a certain amount is reached turn decline and ultimately determine when the rare earth Ce addition is 1%, its best performance.Key words: Mg-Li Alloy ;Alloy ;Thermal Conductivity ;Shrinkage;Microstructure;Mechanical Properties黑龙江工程学院本科生毕业论文目 录摘 要 ...........................................................................................................................IAbstract .......................................................................................................................II第 1 章 绪 论 ..........................................................................................................11.1 镁及镁合金的发展和应用 ..............................................................................11.1.1 镁的基本特性 .........................................................................................11.1.2 镁合金的主要性能和优点 .....................................................................21.1.3 镁合金强化机理 .....................................................................................31.1.4 镁合金中合金元素的作用 .....................................................................51.2 镁锂合金的研究状况 ......................................................................................61.2.1 镁锂合金研究的现状 .............................................................................61.2.2 镁锂系合金的应用前景 ........................................................................81.3 研究的主要内容 ...............................................................................................8第 2 章 镁锂合金的制备 .....................................................................................102.1 成分设计 ........................................................................................................102.2 实验方法 ........................................................................................................112.3 实验原料、设备及制备过程 ........................................................................122.3.1 实验原料与设备 ...................................................................................122.3.2 合金的制备过程 ...................................................................................122.3.3 合金的均匀化处理 ...............................................................................142.4 本章小结 ........................................................................................................15第 3 章 镁锂合金的铸态组织及力学性能 ....................................................163.1 铸态合金的实际化学成分 .............................................................................163.2 铸态合金的显微组织 .....................................................................................163.3 铸态合金的相组成分析 ................................................................................183.3.1 铸态合金的 XRD 分析 ........................................................................183.3.2 铸态合金的 EDS 分析 ........................................................................20黑龙江工程学院本科生毕业论文3.4 铸态实验合金的力学性能 ............................................................................213.5 本章小节 ........................................................................................................22结 论 ........................................................................................................................23参考文。