朱家萱,闫钊鸣,张治民,张冠世,潘玉田,张龙.热处理对GWZK94合金微观组织与力学性能的影响[J].稀有金属材料与工程,2020,49(5):1503~1511.[Zhu Jiaxuan,Yan Zhaoming,Zhang Zhimin,Zhang Guanshi,Pan Yutian,Zhang Long.Evaluating the influence of heat treatment on the microstructure evolution and mechanical properties of GWZK94 alloys[J].Rare Metal Materials and Engineering,2020,49(5):1503~1511.]
热处理对GWZK94合金微观组织与力学性能的影响
投稿时间:2019-09-15  修订日期:2019-10-25
中文关键词:  GWZK合金  均匀化  LPSO  微观组织  力学性能
基金项目:山西省自然科学基金201801D121106
中文摘要:
      为了改善铸态GWZK94合金微观组织的不均匀性,使用电阻加热炉在温度505-520 ℃范围内保温8-20 h进行热处理实验。本文采用光学显微镜(OM),差示扫描量热仪(DSC),X射线衍射仪(XRD),扫描电子显微镜(SEM),能谱仪(EDS),电子背散射衍射技术(EBSD),万能试验机和维氏硬度计进行微观组织演变及力学性能分析。铸态合金组织主要包括树枝状α-Mg基体,包含亚稳态层错(SFs)的片层结构,共晶相Mg24(Gd, Y, Zn)5,块状长周期有序堆垛结构(LPSO, Mg12(Gd, Y) Zn)和少量的富稀土相。在均匀化处理过程中,片层结构和共晶相Mg24(Gd, Y, Zn)5逐渐溶于基体中,同时块状LPSO相体积分数逐渐减小并伴随有片层状LPSO相像晶粒内部生长,颗粒状相在晶界附近析出。加热温度为520 ℃时出现复熔三角晶界,说明此时发生了合金的过烧现象。经过均匀化处理后,合金的极限抗拉强度(UTS)和合金屈服强度(TYS)表现出了与组织演变规律相同的变化趋势,同属得到了较为均匀的硬度分布情况。最佳的均匀化制度为515 ℃/16 h.
Evaluating the influence of heat treatment on the microstructure evolution and mechanical properties of GWZK94 alloys
英文关键词:GWZK94 alloys  homogenization  LPSO  microstructure  mechanical properties
英文摘要:
      In order to eliminate the inhomogeneous structure of as-cast GWZK94 alloys, the homogenization with the temperature range of 505-520 ℃ and the time range of 8-20 h were conducted by using resistance heating furnace. Optical microscope (OM), differential scanning calorimeter (DSC), X-ray diffraction (XRD), scanning electron microscope (SEM), energy dispersive spectroscopy (EDS), electron backscatter diffraction (EBSD), universal mechanical tester, and Vickers hardness tester were applied to investigate the microstructure evolution and mechanical properties. The as-cast alloy mainly consisted of the dendritic α-Mg matrix, lamellae with metastable stacking faults (SFs), Mg24(Gd, Y, Zn)5 which was a eutectic phase, bulk-shaped long-period stacking ordered (LPSO) phases (Mg12(Gd, Y) Zn), and a few RE-rich phases. During the homogenization, the lamellae and Mg24(Gd, Y, Zn)5 eutectic phases gradually dissolved into the matrix, and the volume fraction of bulk-shaped LPSO phases decreased while the lamellar-shaped LPSO phases grew into grains steadily, while some precipitated particle phases formed near the grain boundaries. At 520 ℃, triangle-shaped remelting eutectic phases appeared which indicated the over burning of magnesium alloy. Both ultimate tensile strength (UTS), tensile yield strength (TYS) and fracture elongation showed a tendency to correspond to microstructure evolution, and a more uniform hardness was investigated. The homogenization condition was optimized to be 515 ℃/16 h..
作者单位E-mail
朱家萱 中北大学机电工程学院 nucjxzhu@126.com 
闫钊鸣 中北大学材料科学与工程学院  
张治民 中北大学材料科学与工程学院  
张冠世 中北大学材料科学与工程学院  
潘玉田 中北大学机电工程学院  
张龙 湖北江山重工有限责任公司  
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