A Monte Carlo model for the intermittent plasticity of micro-pillars

被引:23
作者
Ng, K. S. [1 ]
Ngan, A. H. W. [1 ]
机构
[1] Univ Hong Kong, Dept Mech Engn, Hong Kong, Hong Kong, Peoples R China
关键词
D O I
10.1088/0965-0393/16/5/055004
中图分类号
T [工业技术];
学科分类号
08 ;
摘要
Earlier compression experiments on micrometre-sized aluminium pillars, fabricated by focused-ion beam milling, using a flat-punch nanoindenter revealed that post-yield deformation during constant-rate loading was jerky with interspersing strain bursts and linear elastic segments. Under load hold, the pillars crept mainly by means of sporadic strain bursts. In this work, a Monte Carlo simulation model is developed, with two statistics gathered from the load-ramp experiments as input, to account for the jerky deformation during the load ramp as well as load hold. Under load-ramp conditions, the simulations successfully captured other experimental observations made independently from the two inputs, namely, the diverging behaviour of the jerky stress-strain response at higher stresses, the increase in burst frequency and burst size with stress and the overall power-law distribution of the burst size. The model also predicts creep behaviour agreeable with the experimental observations, namely, the occurrence of sporadic bursts with frequency depending on stress, creep time and pillar dimensions.
引用
收藏
页数:14
相关论文
共 26 条
[11]  
Greer JR, 2006, REV ADV MATER SCI, V13, P59
[12]   Size effects under homogeneous deformation of single crystals: A discrete dislocation analysis [J].
Guruprasad, P. J. ;
Benzerga, A. A. .
JOURNAL OF THE MECHANICS AND PHYSICS OF SOLIDS, 2008, 56 (01) :132-156
[13]   Physics and phenomenology of strain hardening: the FCC case [J].
Kocks, UF ;
Mecking, H .
PROGRESS IN MATERIALS SCIENCE, 2003, 48 (03) :171-273
[14]   Stochastic theory for jerky deformation in small crystal volumes with pre-existing dislocations [J].
Ng, K. S. ;
Ngan, A. H. W. .
PHILOSOPHICAL MAGAZINE, 2008, 88 (05) :677-688
[15]   Stochastic nature of plasticity of aluminum micro-pillars [J].
Ng, K. S. ;
Ngan, A. H. W. .
ACTA MATERIALIA, 2008, 56 (08) :1712-1720
[16]   Creep of micron-sized aluminium columns [J].
Ng, K. S. ;
Ngan, A. H. W. .
PHILOSOPHICAL MAGAZINE LETTERS, 2007, 87 (12) :967-977
[17]   Size dependence and stochastic nature of yield strength of micron-sized crystals:: a case study on Ni3Al [J].
Ngan, A. H. W. ;
Zuo, L. ;
Wo, P. C. .
PROCEEDINGS OF THE ROYAL SOCIETY A-MATHEMATICAL PHYSICAL AND ENGINEERING SCIENCES, 2006, 462 (2070) :1661-1681
[18]   Indentation size effects in crystalline materials: A law for strain gradient plasticity [J].
Nix, WD ;
Gao, HJ .
JOURNAL OF THE MECHANICS AND PHYSICS OF SOLIDS, 1998, 46 (03) :411-425
[19]   Contribution to size effect of yield strength from the stochastics of dislocation source lengths in finite samples [J].
Parthasarathy, Triplicane A. ;
Rao, Satish I. ;
Dimiduk, Dennis M. ;
Uchic, Michael D. ;
Trinkle, Dallas R. .
SCRIPTA MATERIALIA, 2007, 56 (04) :313-316
[20]  
SMALLMAN RE, 2007, PHYS METALLURGY ADV, P334