Unusual plastic deformability in a Zr-based bulk metallic glass after structural relaxation

被引:5
作者
Xie, S. H. [2 ]
Zeng, X. R. [1 ,3 ]
Qian, H. X. [1 ,3 ]
Hu, Q. [2 ]
Zheng, Z. Y. [1 ,3 ]
机构
[1] Shenzhen Univ, Coll Mat Sci & Engn, Shenzhen 518060, Peoples R China
[2] NW Polytech Univ, Sch Mat Sci & Engn, Xian 710072, Peoples R China
[3] Shenzhen Key Lab Special Funct Mat, Shenzhen 518060, Peoples R China
关键词
Bulk metallic glass; Plastic deformation; Apparent activation volume; Structural relaxation; FREE-VOLUME; ROOM-TEMPERATURE; TRANSITION TEMPERATURE; AMORPHOUS-ALLOYS; PHASE-SEPARATION; MODEL; DEFORMATION; DISPERSIONS; COMPOSITES; DUCTILITY;
D O I
10.1016/j.jallcom.2010.04.012
中图分类号
O64 [物理化学(理论化学)、化学物理学];
学科分类号
070304 ; 081704 ;
摘要
The structural stability is an essential problem for engineering application of bulk metallic glasses (BMGs). Constant-heating dilatometric measurements were conducted for 2 mm Zr(63.78)Cu(14.72)Ni(10)Al(10)Nb(1.5) BMG rods and two visible structural relaxation processes below T(g) were found, which correspond to the obvious annihilation of free volume (FV) and the continuous decrease in coefficient of linear thermal expansion (alpha). After annealing the BMGs near the temperature of the main structural relaxation processes and T(g) for 3600 s, the BMG rods have much FV relaxed, but still remain the amorphous structure. The microhardness of the annealed samples increases with increasing the annealing temperature, but the plastic strains remain unchanged considering the uncertainty of uniaxial compression after annealing the BMGs at the temperature below T(g). The excellent plasticity of the BMGs experienced the structural relaxation is absolutely different from those previous results of embrittlement after structural relaxation below T(g). The mechanisms of this unusual plastic deformability for the BMGs experienced the structural relaxation below T(g) is discussed in the light of apparent activation volume. (C) 2010 Elsevier B.V. All rights reserved.
引用
收藏
页码:S86 / S90
页数:5
相关论文
共 38 条
[1]  
AKIRA T, 2005, MAT T, V46, P2729
[2]   Metallic glasses as structural materials [J].
Ashby, MF ;
Greer, AL .
SCRIPTA MATERIALIA, 2006, 54 (03) :321-326
[3]   Free volume model: High-temperature deformation of a Zr-based bulk metallic glass [J].
Bletry, M ;
Guyot, P ;
Blandin, JJ ;
Soubeyroux, JL .
ACTA MATERIALIA, 2006, 54 (05) :1257-1263
[4]   New class of plastic bulk metallic glass [J].
Chen, L. Y. ;
Fu, Z. D. ;
Zhang, G. Q. ;
Hao, X. P. ;
Jiang, Q. K. ;
Wang, X. D. ;
Cao, Q. P. ;
Franz, H. ;
Liu, Y. G. ;
Xie, H. S. ;
Zhang, S. L. ;
Wang, B. Y. ;
Zeng, Y. W. ;
Jiang, J. Z. .
PHYSICAL REVIEW LETTERS, 2008, 100 (07)
[5]   Free-volume-induced enhancement of plasticity in a monolithic bulk metallic glass at room temperature [J].
Chen, L. Y. ;
Setyawan, A. D. ;
Kato, H. ;
Inoue, A. ;
Zhang, G. Q. ;
Saida, J. ;
Wang, X. D. ;
Cao, Q. P. ;
Jiang, J. Z. .
SCRIPTA MATERIALIA, 2008, 59 (01) :75-78
[6]   Change in free volume during the homogeneous flow of Zr-based bulk metallic glass matrix composite [J].
Chen, Q. ;
Liu, L. ;
Chan, K. C. .
JOURNAL OF ALLOYS AND COMPOUNDS, 2009, 467 (1-2) :208-212
[7]   Negative strain rate sensitivity in bulk metallic glass and its similarities with the dynamic strain aging effect during deformation [J].
Dalla Torre, Florian H. ;
Dubach, Alban ;
Siegrist, Marco E. ;
Loeffler, Joerg F. .
APPLIED PHYSICS LETTERS, 2006, 89 (09)
[8]   Structural changes in bulk metallic glass after annealing below the glass-transition temperature [J].
Dmowski, W. ;
Fan, C. ;
Morrison, M. L. ;
Liaw, P. K. ;
Egami, T. .
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING, 2007, 471 (1-2) :125-129
[9]   Constitutive model for inhomogeneous flow in bulk metallic glasses [J].
Dubach, Alban ;
Dalla Torre, Florian H. ;
Loeffler, Joerg F. .
ACTA MATERIALIA, 2009, 57 (03) :881-892
[10]   Molecular-dynamics study of ductile and brittle fracture in model noncrystalline solids [J].
Falk, ML .
PHYSICAL REVIEW B, 1999, 60 (10) :7062-7070