Tensile and fracture behavior of free-standing copper films

Keller, Robert R.; Phelps, J. M.; Read, David T.

doi:10.1016/0921-5093(96)10253-7

Cited by 88 publications

(47 citation statements)

References 21 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…For the case of electron beam-evaporated 0.26-m-thick Cu freestanding films, similar results were obtained in in situ TEM tensile tests (10). The stress level at the onset of plastic deformation and the rate of hardening were similar to those reported in ref.…”

supporting

confidence: 76%

“…For instance, in the in situ TEM tensile tests reported in ref. 10, the limited ductility of the films during straining is explained by a low number of available dislocation sources with the most likely sites for nucleation being grain boundaries. This feature is also consistent with other in situ TEM observations showing dislocations bowing away from grain boundaries and moving outward from the grains during straining (19,20).…”

Section: The Computational Modelmentioning

confidence: 99%

“…Dislocations were observed to sweep the grains and leave no trace within the crystal. Based on this mechanism and the measured plastic strain before failure, Keller et al (10) concluded that only one dislocation every three or four grains was needed at the onset of yielding. In turn, this count resulted in a mobile dislocation density ranging from 2 ϫ 10 9 to 8 ϫ 10 9 m Ϫ2 .…”

mentioning

confidence: 99%

See 2 more Smart Citations

An interpretation of size-scale plasticity in geometrically confined systems

Espinosa

Berbenni

Panico³

et al. 2005

Proc. Natl. Acad. Sci. U.S.A.

View full text Add to dashboard Cite

The mesoscopic constitutive behavior of face-centered cubic metals as a function of the system characteristic dimension recently has been investigated experimentally. Strong size effects have been identified in both polycrystalline submicron thin films and single crystal micro pillars. The size effect is manifested as an increase in strength and hardening rate as the system dimensions are decreased. In this article, we provide a mechanistic interpretation for the observed mesoscopic behavior. By performing 3D discrete dislocation dynamics simulations of grains representative of the system microstructure and associated characteristic dimensions, we show that the experimentally observed size effects can be qualitatively described. In these simulations, a constant density of dislocation sources per unit of grain boundary area is modeled by sources randomly distributed at grain boundaries. The source length (strength) is modeled by a Gaussian distribution, in which average and standard deviation is independent of the system characteristic dimension. The simulations reveal that two key concepts are at the root of the observed plasticity size effect. First, the onset of plasticity is governed by a dislocation nucleationcontrolled process (sources of various length, i.e., strengths, in our model). Second, the hardening rate is controlled by source exhaustion, i.e., sources are active only once as a result of the limited dislocation mobility arising from size and boundary effects. The model postulated here improves our understanding of why ''smaller is stronger'' and provides predictive capabilities that should enhance the reliable design of devices in applications such as microelectronics and micro͞nano-electro-mechanical systems.thin films ͉ dislocation dynamics ͉ strengthening A t the mesoscale, material behavior depends strongly on the system characteristic dimensions, e.g., material grain size, film thickness, etc. Size-scale plasticity has recently been the focus of research on both of these aspects. Concerning the material grain size effect, extensive research has been pursued on the mechanical behavior of nanocrystalline materials for which the grain size is on the order of 30 nm or smaller. For these systems, grain size effects and deviations from the classical Hall-Petch law have been identified (1). The size effect was attributed to a transition in deformation mechanism from a dislocation-dominated regime to grain boundary sliding (2). Another equally strong size effect, at constant grain size, has been correlated to sample dimensions. The so-called membrane deflection experiment (MDE) was used in the characterization of freestanding polycrystalline face-centered cubic (f.c.c.) thin films subjected to pure uniform tension (3, 4). In ref. 5, important size effects were reported, in the absence of macroscopic strain gradients, for Cu, Al, and Au films when the film thickness was varied from 0.2 to 1 m. The films were deposited by e-beam evaporation and exhibited an average grain size of Ϸ200 nm independent of t...

show abstract

supporting

confidence: 76%

Section: The Computational Modelmentioning

confidence: 99%

mentioning

confidence: 99%

See 1 more Smart Citation

An interpretation of size-scale plasticity in geometrically confined systems

Espinosa

Berbenni

Panico³

et al. 2005

Proc. Natl. Acad. Sci. U.S.A.

View full text Add to dashboard Cite

show abstract

“…Piezoelectric device (Keller et al, 1996;Liu et al, 2009;Tsuchiya et al, 2000) and electromagnetic actuator (Kim & Huh, 2011;Komai et al, 1998), which can control nanometer order displacement, are used as an actuator. Load is measured by means of capacitive load cell (Zhu et al, 2005).…”

Section: Experimental Set-upmentioning

confidence: 99%

In-Situ Mechanical Testing of Nano-Component in TEM

Sumigawa¹,

Kitamura²

2012

The Transmission Electron Microscope

View full text Add to dashboard Cite

“…Consequently, several custom methods optimized for thin film investigations have been developed during the past decades. 6 The most prominent ones are based on static deflection measurements of thin-film specimens such as substrate curvature measurements, 13,14 nanoindentation techniques, [15][16][17] microtensile experiments, [18][19][20][21] and bulge tests. [22][23][24] Dynamic measurement principles utilizing resonance frequency determination of vibrating thin films are also in use.…”

Section: Introductionmentioning

confidence: 99%

A two-step load-deflection procedure applicable to extract the Young's modulus and the residual tensile stress of circularly shaped thin-film diaphragms

Beigelbeck

Schneider

Schalko

et al. 2014

Journal of Applied Physics

View full text Add to dashboard Cite

We report on a novel two-step load-deflection (LD) formula and technique that enables an accurate extraction of the Young's modulus and the residual tensile stress from LD measurements on circularly shaped thin-film diaphragms. This LD relationship is derived from an adaptation of Timoshenko's plate bending theory, where the in-plane and out-of-plane deflections are approximated by series expansions. Utilizing the minimum total potential energy principle yields an infinitedimensional system of equations which is solved analytically resulting in a compact closed-form solution. In the appendant measurement procedure, the whole transverse bending characteristic of the diaphragm as a function of the radial coordinate is recorded for different pressure loads and introduced into the novel LD equation in order to determine the elastomechanical parameters of interest. The flexibility of this approach is demonstrated by ascertaining the Young's modulus and the residual tensile stress of two disparate diaphragm materials made of either micromachined silicon or microfiltered buckypapers composed of carbon nanotube compounds. V C 2014 AIP Publishing LLC.

show abstract

Tensile and fracture behavior of free-standing copper films

Cited by 88 publications

References 21 publications

An interpretation of size-scale plasticity in geometrically confined systems

An interpretation of size-scale plasticity in geometrically confined systems

In-Situ Mechanical Testing of Nano-Component in TEM

A two-step load-deflection procedure applicable to extract the Young's modulus and the residual tensile stress of circularly shaped thin-film diaphragms

Contact Info

Product

Resources

About