金属玻璃微观形貌对晶化过程的影响

金属玻璃微观形貌对晶化过程的影响

宋 晓^1,2, 倪晓东¹，姚 湲^2*，禹日成²，闻 平²

（1.北京科技大学数理学院，北京100083；2．中国科学院物理研究所北京凝聚态国家实验室，北京100190)

摘  要：使用电解双喷法制备了金属玻璃中的环状和带状结构，利用扫描透射电子显微镜（STEM）、X射线能谱( EDS)和电子能量损失谱(EELS)等手段，没有发现明显的相分离现象，证实这些结构主要是样品厚度起伏导致的衬度变化。进一步原位退火实验表明，这些环状或条带状结构在加热后发生了明显地相分离，其中Ni和Cu元素聚集在厚区和薄区的交界处，产生了明显的偏聚现象，而Al的偏聚现象并不明显。这表明金属玻璃中的微观结构形貌可以显著地影响金属玻璃在晶化过程的相分离，局域偏析可能与Cu和Ni在厚区与薄区交界处优先成核有关，同时表面扩散速率与体扩散速率的差异也是导致晶化后元素浓度变化的原因之一。

关键词：金属玻璃；电解双喷；环状衬度结构；相分离；晶化

       中图分类号：TQ171.7；O646；O766；TG115.21⁺5.3         文献标识码：A     

       doi:10.3969/j.1000-6281.2014.01.004

The effect of themicrostructure of metallic glasses on the crystallization process

SONG Xiao^1,2, NI Xiao-dong¹, YAO Yuan^2*, YU Ri-cheng², WEN Ping²

(1. Department of Physics, University of Science and Technology Beijing, Beijing 100083；2. Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190，China)

Abstract: The annular andstriped features in the bulk metallic glass samples thinned by electropolishing are researched by the means of scan transmission electron microscopy(STEM), energy dispersive spectrometry (EDS) and electron energy-loss spectroscopy(EELS). The results show that these features are resulted from thickness variation of samples instead of phase separation. Further in-situ observation of the annealing sample shows that remarkable phase separations emerge in the annular or striped features; in addition, Ni and Cu concentrate on the boundary between the thicker and thinner area and significant segregation of them is observed, while the segregation of Al is unobvious. The observation indicates that the microstructures of metallic glasses have an significant effect on the phase separation in the crystallization process, and the local segregation is probably related to the preferred nucleation of Ni and Cu on the boundary between the thicker and thinner area. Also, the difference between surface diffusion and bulk diffusion is one of the factors that account for the element concentration variation in the crystallized alloy.

Keywords: metallic glasses；electropolishing；striped features; phase separation；crystallization

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[1]赵兵兵，李春艳，王英敏，等.Zr-Al-Co-Cu 块状金属玻璃晶化相的TEM 研究[J]. 电子显微学报, 2013, 32(1): 14-17.

[2] Telford M. The case for bulk metallic glass [J]. Materials Today, 2004, 7(3): 36-43.

[3]  Inoue A, Takeuchi A. Recent development and application products of bulk glassy alloys [J]. Acta Materialia, 2011, 59(6): 2243-2267.

[4]Zhang T, Inoue A, Masumoto T. Amorphous Zr-Al-TM (TM= Co, Ni, Cu) alloys with significant supercooled liquid region of over 100 K [J]. Mater Trans JIM, 1991, 32(11): 1005-1010.

[5]  Peker A, Johnson W L. A highly processable metallic glass: ZrTiCuNiBe [J]. Applied Physics Letters, 1993, 63: 2342.

[6]  Inoue A, Zhang T, Kim Y H. Synthesis of high strength bulk amorphous Zr-Al-Ni-Cu-Ag alloys with a nanoscale secondary phase [J]. Materials Transactions, JIM(Japan)，1997，38(9): 749-755.

[7]  Inoue A. Stabilization of metallic supercooled liquid and bulk amorphous alloys [J].  Acta Materialia，2000，48(1): 279-306.

[8] 陈延，黄文军，尚沙沙，等. 锆基块体非晶合金力学性能的研究进展[J]. 上海有色金属，2011，32(2): 79-83.

[9]  Inoue A, Kawase D, Tsai A P, et al. Stability and transformation to crystalline phases of amorphous ZrAlCu alloys with significant supercooled liquid region [J]. Materials Science and Engineering: A, 1994, 178(1~2): 255-263.

[10]   Köster U, Meinhardt J, Roos S, et al. Formation of quasicrystals in bulk glass forming Zr-Cu-Ni-Al alloys [J]. Applied Physics Letters, 1996, 69: 179.

[11]   Chen M, Zhang T, Inoue A, et al. Quasicrystals in a partially devitrified ZrAlNiCuAg bulk metallic glass [J]. Applied Physics Letters, 1999, 75: 1697.

[12]   Nagase T, Umakoshi Y. Electron irradiation induced crystallization of the amorphous phase in Zr_65.0Al_7.5Ni_10.0 Cu_17.5 metallic glass [J]. Science and Technology of Advanced Materials, 2004, 5(1-2): 57.

[13]   Nagahama D, Ohkubo T, Hono K. Crystallization of Ti₃₆Zr₂₄Be₄₀ metallic glass[J]. Scripta Materialia, 2003, 49(7): 729-734.

[14]   Yang H, Chang X, Hou W, et al. TEM specimen preparation for Al-based amorphous alloys [J]. Journal of Materials Science and Technology-Shenyang, 2006, 22(5): 655.

[15]   Sun B, Wang Y, Wen J, et al. Artifacts induced in metallic glasses during TEM sample preparation [J]. Scripta Materialia, 2005, 53(7): 805-809.

[16]   Schweiss D, Hwang J, Voyles P. Inelastic and elastic mean free paths from FIB samples of metallic glasses [J]. Ultramicroscopy, 2012:

[17]   惠希东, 陈国良. 块体非晶合金[M]. 北京: 化工出版社, 2007.

[18]   MolokanoV V, Mikhailova TN, Kliger A I, et al.Comparative DSC-study of Ni₇₀Mo₁₀P₂₀ and Zr₆₅Al₇₅Cu1₇₅Ni₁₀ metallic glasses in Tg-Tx temperature range [J]. Materials Science & Engineering, 1997, 226(228): 474-478.

[19]   Köster U. The influence of the specimen surface on thermally induced structural changes [J]. Kristall und Technik, 1979, 14(11): 1369-1376.

[20]   Zhu L, Brian C, Swallen S, et al. Surface self-diffusion of an organic glass [J]. Physical Review Letters, 2011, 106(25): 256103.

[21]   Capaccioli S, Ngai K, Paluch M, et al. Mechanism of fast surface self-diffusion of an organic glass [J]. Physical Review E, 2012, 86(5): 051503.