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摘要：
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利用OM、SEM和EDS研究稀土元素Pr变质对AZ91镁合金的微观组织的影响，并探究其与合金显微组织及力学性能的关系。结果表明，随着稀土元素Pr含量的增加，粗大树枝状的β-Mg17Al12相开始断裂，尺寸逐渐减小。当Pr添加量（质量分数）为1.0%时，粗大树枝状的β-Mg17Al12相断裂为短棒状。然而，当Pr含量继续增加时，β-Mg17Al12相尺寸又开始变大。随着Pr的添加，合金中生成条状Al11Pr3相和块状Al6Mn6Pr相。热挤压可以显著细化铸态AZ91镁合金晶粒，挤压后，β-Mg17Al12相沿挤压方向有序排列。随着Pr含量的增加，挤压态AZ91镁合金的力学性能呈现先上升后下降的趋势。当稀土元素Pr添加量为1.0%时，AZ91镁合金力学性能最佳，合金抗拉强度、伸长率、硬度较基体分别提升了20.5%，26.0%和18.5%。
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The influence of rare earth element Pr on the microstructure and mechanical properties of magnesium alloy AZ91 was investigated by OM, SEM and EDS, and the relationship between the microstructure and mechanical properties of magnesium alloy AZ91 was discussed. The results show that with increasing of Pr content, coarse dendritic β-Mg17Al12 phase begins to break, and the size becomes smaller gradually. When Pr content is up to 1.0% (mass fraction), the shape of coarse dendritic β-Mg17Al12 phase changes into short rod. However, when Pr content increases continually, the size of β-Mg17Al12 phase increases again, and stripe Al11Pr3 phase and globular Al6Mn6Pr phase form in the alloy. Thus, hot extrusion can significantly reduce the grain size of as-cast magnesium alloy AZ91, and β-Mg17Al12 phase arranges orderly along the extrusion direction after extrusion. With the increase of Pr content, mechanical properties of as-extrusion magnesium alloy AZ91 firstly decrease and then increase. When Pr content is up to 1.0%, the mechanical properties reach optimum, and the tensile strength, elongation and hardness of the as-extruded AZ91 are increased by 20.5%, 26.0% and 18.5%, respectively.
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基金项目：
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江西省自然科学基金资助项目 (20171BAB206034)
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作者简介：
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作者简介：吴烁（1992-），男，硕士研究生
E-mail：wushuo199201@163.com
通讯作者：闫洪（1962-），男，博士，教授，博士生导师
E-mail：yanhong_wh@163.com
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参考文献：
|
［1］陈拂晓，郭云汉，郭俊卿,等. AZ31B镁合金热压缩力学行为与本构方程建立
［J］. 锻压技术，2011，36(5):144-148.
Chen F X，Guo Y H，Guo J Q，et al. Mechanical behavior and constitutive equation of AZ31B magnesium alloy at hot compression
［J］. Forging & Stamping Technology，2011，36(5):144-148.
［2］薛勇，张治民，郎利辉,等. AZ91D镁合金高温压缩变形行为
［J］. 锻压技术，2009，34(1):135-138.
Xue Y，Zhang Z M，Lang L H，et al. High temperature compression deformation behaviors of AZ91D alloy
［J］. Forging & Stamping Technology，2009，34(1):135-138.
［3］冯晓伟，戚文军，黎小辉,等. Mg-Zn-Gd合金的微观组织和力学性能
［J］. 稀有金属，2016，40(1):14-19.
Feng X W，Qi W J，Li X H，et al. Microstructure and mechanical properties of Mg-Zn-Gd Alloys
［J］. Chinese Journal of Rare Metals，2016，40(1):14-19.
［4］杜磊，闫洪. 等温热处理对AZ61稀土镁合金半固态组织的影响
［J］. 材料研究学报，2012，26(2):169-174.
Du L，Yan H. Effect of isothermal heat-treated on the microstructure of AZ61 rare earth magnesium alloy
［J］. Journal of Material Research，2012，26(2):169-174.
［5］Wang Z W，Yan H，Huang W X. Effect of solution treatment on microstructure and hardness of rheo-forming AZ91-Y alloy
［J］. China Foundry，2016，13(6):383-388.
［6］赵旭，张奎，李兴刚,等. Gd含量及热处理对Mg-Gd-Zr合金显微组织和力学性能的影响
［J］. 稀有金属，2017，41(4):356-363.
Zhao X，Zhang K，Li X G，et al. Microstructure and mechanical properties of Mg-Gd-Zr alloys with Gd additive and heat treatment
［J］. Chinese Journal of Rare Metals，2017，41(4):356-363.
［7］赵宇昕. 镁合金超声处理细化机制及工艺研究
［D］. 北京：北京工业大学，2010.
Zhao Y X. Study on Mechanism and Technology about Ultrasonic Treatent of Magnesium Alloy
［D］. Beijing:Beijing University of Technology，2010.
［8］Hsiang S H，Kuo J L. An investigation on the hot extrusion process of magnesium alloy sheet
［J］. Journal of Materials Processing Technology，2003，140(1-3):6-12.
［9］Xiao W，Shen Y，Wang L，et al. The influences of rare earth content on the microstructure and mechanical properties of Mg-7Zn-5Al alloy
［J］. Materials & Design，2010，31(7):3542-3549.
［10］吴道高，颜世宏，李宗安,等. 稀土Sm对AZ92镁合金耐腐蚀性能的影响
［J］. 稀有金属，2013，37(2):199-206.
Wu D G，Yan S H，Li Z A，et al. Effect of samarium on corrosion behavior of as-cast AZ92 magnesium alloy
［J］. Chinese Journal of Rare Metals，2013，37(2):199-206.
［11］曹春虎，薛勇，张治民,等. 铸态稀土镁合金的高温断裂机制研究
［J］. 热加工工艺，2016，45(8):127-130.
Cao C H，Xue Y，Zhang Z M，et al. Research on high temperature fracture mechanism of cast rare earth
［J］. Hot Working Technology，2016，45(8):127-130.
［12］GB/T 228.1—2010，金属材料拉伸试验第1部分:室温试验方法
［S］.
GB/T 228.1—2010，Metallic materials—Tensile testing—Part 1:Method of test at elevated temperature
［S］.
［13］GB/T 4340.1—2009，金属维氏硬度试验
［S］.
GB/T 4340.1—2009，Metal Vickers hardness test
［S］.
［14］孟赢，刘海峰，佟国栋. Pr对AZ91压铸镁合金耐腐蚀性能的影响
［J］. 材料应用，2010，(12):52-54.
Meng Y，Liu H F，Tong G D. Effect of Pr on corrosion resistance of AZ91 die-casting magnesium alloy
［J］. Material Application,2010，(12):52-54.
［15］Tham L M，Gupta M，Cheng L. Effect of reinforcement volume fraction on the evolution of reinforcement size during the extrusion of Al-SiC composites
［J］. Materials Science & Engineering A，2002，326(2):355-363.
［16］Zhang Y，Zeng X，Liu L，et al. Effects of yttrium on microstructure and mechanical properties of hot-extruded Mg-Zn-Y-Zr alloys
［J］. Materials Science & Engineering A，2004，373(1-2):320-327.
［17］Yuan Q H，Zeng X S，Liu Y，et al. Microstructure and mechanical properties of AZ91 alloy reinforced by carbon nanotubes coated with MgO
［J］. Carbon，2016，96(1):843-855.
［18］Wu Q J，Yan H. Fabrication of carbon nanofibers/A356 nanocomposites by high-intensity ultrasonic processing
［J］. Metallurgical & Materials Transactions A，2018，49(6):2363-2372.
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