利用光学显微镜、XRD衍射分析仪、扫描电子显微镜、透射电子显微镜、万能拉伸试验机等仪器设备研究了Mg-4Y-2.5Nd-0.6Zr合金铸态、固溶态和峰时效态的微观组织、室温和高温力学特性及断裂行为。结果表明：合金的铸态组织主要由α-Mg、Mg41Nd5和Mg24Y5组成；经固溶处理，共晶组织完全溶入基体，仅残余方块相Mg24Y5；再经时效处理，晶内弥散析出大量β″和β′相，有效强化了合金，对应的室温抗拉强度、屈服强度和伸长率分别为292、215 MPa和4%；随着拉伸温度的提高，峰时效态合金的强度逐渐降低、伸长率逐渐增加，室温断裂类型为解理断裂，而250℃的断裂方式表现为准解理断裂。
Microstructures,mechanical properties and fracture behaviors of Mg-4Y-2.5Nd-0.6Zr alloy at different states were investigated by Optical Microscope(OM),X-ray Diffractometer(XRD),Scanning Electron Microscope(SEM),Transmission Electron Microscope(TEM)and universal tensile test machine. Results show that the as-cast sample mainly consists of α-Mg matrix,Mg41Nd5 phase and Mg24Y5 particle. After solution treatment,the eutectic compounds completely dissolve into the matri. with a few cuboid-shaped particles remained. After subsequent ageing,a great number of dispersed β″and β′ precipitates distribute throughout the matrix,which strengthens the alloy,corresponding to mechanical properties as follows:σb=292 MPa,σ0.2=215 MPa andδ=4%. Besides,the strength of peak-aged sample decreases gradually with a gradual increase of ductility. The peak-aged sample exhibits cleavage fracture mode at room temperature,and the sample shows a quasi-cleavage fracture at 250℃.
参考文献
| [1] | 刘正;张奎;曾小勤.镁基轻质合金理论基础及其应用[M].北京:机械工业出版社,2002:1-2. |
| [2] | 陈振华.镁合金[M].北京:化学工业出版社,2004:19-22. |
| [3] | 丁文江.镁合金科学与技术[M].北京:科学出版社,2007:24-26. |
| [4] | 余琨,黎文献,李松瑞,谭敦强.含稀土镁合金的研究与开发[J].特种铸造及有色合金,2001(01):41-43. |
| [5] | J. F. Nie and B. C. Muddle .CHARACTERISATION OF STRENGTHENING PRECIPITATE PHASES IN A Mg-Y-Nd ALLOY[J].Acta materialia,2000(8):1691-1703. |
| [6] | J.F.Nie;B.C.Muddle .PRECIPITATION IN MAGNESIUM ALLOY WE54 DURING ISOTHERMAL AGEING AT 250℃[J].Scripta materialia,1999(10):1089-1094. |
| [7] | C. Antion;P. Donnadieu;F. Perrard;A. Deschamps;C. Tassin;A. Pisch .Hardening precipitation in a Mg-4Y-3RE alloy[J].Acta materialia,2003(18):5335-5348. |
| [8] | 胡耀波,邓娟,赵冲,王敬丰,潘复生.固溶态Mg-Gd-Zr合金的组织与力学性能[J].中国有色金属学报（英文版）,2011(04):732-738. |
| [9] | L. L. Rokhlin;T. V. Dobatkina;I. E. Tarytina .Peculiarities of the phase relations in Mg-rich alloys of the Mg-Nd-Y system[J].Journal of Alloys and Compounds: An Interdisciplinary Journal of Materials Science and Solid-state Chemistry and Physics,2004(1/2):17-19. |
| [10] | Lidong Wang;Chengyao Xing;Xiuli Hou;Yaoming Wu;Jianfei Sun;Limin Wang .Microstructures and mechanical properties of as-cast Mg–5Y–3Nd–Zr–xGd (x = 0, 2 and 4 wt.%) alloys[J].Materials Science & Engineering, A. Structural Materials: Properties, Misrostructure and Processing,2010(7/8):1891-1895. |
| [11] | Renlong Xin;Ling Li;Ke Zeng .Structural examination of aging precipitation in a Mg-Y-Nd alloy at different temperatures[J].Materials Characterization,2011(5):535-539. |
| [12] | Yan Gao;Qudong Wang;Jinhai Gu;Yang Zhao;Yan Tong .Behavior of Mg-15Gd-5Y-0.5Zr alloy during solution heat treatment from 500 to 540℃[J].Materials Science & Engineering, A. Structural Materials: Properties, Misrostructure and Processing,2007(1/2):117-123. |
| [13] | Vagarali S S;Langdon T G .Deformation mechanism in H.C. P. metals at elevated temperatures-I. Creep behavior of mag-nesium[J].Acta Metallurgica,1981,29(12):1969-1982. |
| [14] | S.M. He;X.Q. Zeng;L.M. Peng .Microstructure and strengthening mechanism of high strength Mg-10Gd-2Y-0.5Zr alloy[J].Journal of Alloys and Compounds: An Interdisciplinary Journal of Materials Science and Solid-state Chemistry and Physics,2007(1/2):316-323. |
| [15] | Wu An-ru;Xia Chang-qing .Study of the microstructure and mechanical properties of Mg-rare earth alloys[J].Materials & Design,2007(6):1963-1967. |
- 下载量()
- 访问量()
- 您的评分：
-
10%
-
20%
-
30%
-
40%
-
50%