Theoretical and experimental researches of size effect in micro-indentation test

Citation
Yg. Wei et al., Theoretical and experimental researches of size effect in micro-indentation test, SCI CHINA A, 44(1), 2001, pp. 74-82
Citations number
17
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Multidisciplinary
Journal title
SCIENCE IN CHINA SERIES A-MATHEMATICS PHYSICS ASTRONOMY
ISSN journal
1001-6511 → ACNP
Volume
44
Issue
1
Year of publication
2001
Pages
74 - 82
Database
ISI
SICI code
1001-6511(200101)44:1<74:TAEROS>2.0.ZU;2-4
Abstract
Micro-indentation tests at scales on the order of sub-micron have shown tha t the measured hardness increases strongly with the indent depth or indent size decreasing, which is frequently referred to as the size effect. Howeve r, the trend is at odds with the size-independence implied by conventional elastic-plastic theory. In this paper, strain gradient plasticity theory is used to model the size effect for materials undergoing the micro-indenting , Meanwhile, the micro-indentation experiments for single crystal copper an d single crystal aluminum are carried out. By the comparison of the theoret ical predictions with experimental measurements, the micro-scale parameter of strain gradient plasticity theory is predicted, which is fallen into the region of 0.8-1.5 micron for the conventional metals such as copper (Cu), aluminum (Al) and silver (Ag). Moreover, the phenomena of the pile-up and s ink-in near micro-indent boundary are investigated and analyzed in detail.