Growth behavior of voids randomly distributed at grain boundary on thin metal film with bamboo microstructures under thermal residual stress field and electric field

The growth behavior of a naturally initiated corner crack under a uniform residual stress field is investigated in this study. A convenient method is proposed to induce and evaluate the uniform residual stress field for a beam-type specimen. Fatigue tests are conducted with a rotary bending fatigue machine to investigate the growth of the corner crack. For this reason, a cylindrical specimen, which is typically used for rotating bending tests, is modified into a beam specimen. The corner crack growth behavior under residual stress is evaluated based on linear elastic fracture mechanics (LEFM) and compared with long through crack data. The test results verify that the corner crack growth under residual stress can be effectively evaluated by LEFM and estimated using long crack data.

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Thin Metal Film Sensors

Active and Passive Electronic Components ◽

10.1155/1985/17659 ◽

1985 ◽

Vol 12 (1) ◽

pp. 9-32 ◽

Cited By ~ 4

Author(s):

C. R. Tellier

Keyword(s):

Thin Film ◽

Grain Boundary ◽

Metal Film ◽

Bulk Diffusion ◽

Film Structure ◽

Thin Metal Film ◽

Thin Metal ◽

Structural Defects ◽

Transport Parameters ◽

Theoretical Predictions

During the last decade some progress have been made in the field of sensors using thin film techniques. In particular thin metal film strain gauges and thin film temperature sensors based on the temperature dependent resistivity of metal are now commonly used. But changes in other transport parameters with various measurands are also useful for the design of metal film sensors. Difficulty arises in thin film techniques when structural defects are frozen in films.Intensive theoretical investigations are carried out to explain the effect of grain-boundary and external surface scatterings on transport parameters. Accordingly the main results are presented to specify the influence of film structure on the sensor performance. The grain-boundary effects are discussed according to applications of metal film sensors. Theoretical predictions are analyzed in terms of sensitivity, thermal stability and long term behavior. But other problems induced by the presence of grain boundaries or point defects are also discussed, in particular problems associated with bulk diffusion, electromigration induced failures or intrinsic stresses.

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Finite Element Study of the Creep Size-Effect in Thin Metal Films

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.353-358.1858 ◽

2007 ◽

Vol 353-358 ◽

pp. 1858-1862 ◽

Cited By ~ 1

Author(s):

Li Sha Niu ◽

Ting Ting Dai

Keyword(s):

Finite Element ◽

Grain Boundary ◽

Size Effects ◽

Metal Film ◽

Simulation Method ◽

Thin Metal Film ◽

Lattice Diffusion ◽

Thin Metal ◽

Whole Process ◽

Element Simulation

A 2-D Finite element simulation method was developed based on the kinetic law and the energy evolution during the whole process of deformation, which is used to investigate the creep size effects in polycrystalline thin metal film on substrates. Three diffusion paths (e.g. surface, grain boundary and lattice diffusion) are considered in the present model. The diffusion rate for these three processes was compared under different loading conditions with corresponding microstructure. It’s found that grain boundary diffusion is coupled with another diffusion channel. Creep size effects result from mass transferring in thin film. The model gave the quantitative results of the influences of the film thickness, grain size, and the constraints of the substrate on polycrystalline metal film diffusion. The simulated results present the evolution of the point defects in grain interior, the strain and stress field. The distribution of the crack-like stress in the grain boundary could explain the stress concentration mechanisms clearly and this also agrees with the literature results.

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Estimation of Crack Growth Behavior in a Residual Stress Field Using the Modified Strip-Yield Model

Fatigue and Fracture Mechanics: 29th Volume ◽

10.1520/stp14967s ◽

2009 ◽

pp. 516-516-19

Author(s):

C-Y Hou ◽

J-J Charng

Keyword(s):

Residual Stress ◽

Stress Field ◽

Crack Growth ◽

Growth Behavior ◽

Crack Growth Behavior ◽

Residual Stress Field ◽

Yield Model ◽

Strip Yield Model

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Simulation of Stress Corrosion Cracking in ICM Housing of Nuclear Power Plant

Volume 1: Codes and Standards ◽

10.1115/pvp2012-78264 ◽

2012 ◽

Cited By ~ 1

Author(s):

Masanori Kikuchi ◽

Yoshitaka Wada ◽

Kazuhiro Suga ◽

Fuminori Iwamatsu ◽

Yuichi Shintaku

Keyword(s):

Residual Stress ◽

Stress Field ◽

Stress Corrosion ◽

Crack Growth ◽

Stress Corrosion Cracking ◽

Growth Behavior ◽

Corrosion Cracking ◽

Stress Fields ◽

Crack Growth Behavior ◽

Residual Stress Field

It has been reported that stress corrosion cracking damaged in-core monitor housing (ICM Housing), which occurred in a weld heat-affected zone because of the existence of residual stress. So it is important to evaluate crack growth behavior with high accuracy. In this study, crack growth behavior in ICM Housing is estimated using S-version FEM (S-FEM), which allows generation of the core finite model and the detailed mesh representing the crack independently. At first, axial, slant and circumferential surface cracks are assumed at two locations where residual stress fields are different from each other. One is isotropic residual stress field, and the other is circumferential residual stress field. It is shown that crack growth behaviors are different under different residual stress fields. Next, the effect of the slit, which exists between the ICM Housing and the Pressure Vessel is evaluated. It is shown that the existences of the slit increases stress intensity factors of growing surface crack. Finally S-FEM results are compared with those of the Influence Function Method (IFM), which assumes that an elliptical crack shape exists in a plate. It is shown that IFM result is conservative comparing to that of S-FEM.

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