Determination of proof stress and strain-hardening exponent for thin film with biaxial residual stresses by in-situ XRD stress analysis combined with tensile test

This study focused on stress and strain analysis of the cutting force of a branch knife with a replaceable cutting edge. The replaceable edge forms part of the delimbing head, which is applied to the arms of a mechanical harvester working in forestry. Basic parameters of the knife and head of the harvester with the basic calculations necessary to determine the number of knives based on input parameters, such as wood diameter, woody plants, and determination of the cutting force acting on the cutting knife, were examined. Based on the cutting force and the design of the special cutting knife, a stress analysis and a finite element method (FEM) was performed. This study confirmed the correctness of the selected material to produce the delimbing knife, which was designed using a replaceable cutting edge. The output of the stress analysis is reported.

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Electrocatalytic Oxidation and Determination of Hydrazine in Alkaline Medium through in Situ Conversion Thin Film Nanostructured Modified Carbon Ceramic Electrode

Journal of Electroanalytical Chemistry ◽

10.1016/j.jelechem.2022.116038 ◽

2022 ◽

pp. 116038

Author(s):

Biuck Habibi ◽

Ali Pashazadeh ◽

Sara Pashazadeh ◽

Lotf Ali Saghatforoush

Keyword(s):

Thin Film ◽

Alkaline Medium ◽

Electrocatalytic Oxidation ◽

Carbon Ceramic Electrode ◽

Carbon Ceramic

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Residual Stresses and Differential Deformation of Electroplated Structures

Advances in X-ray Analysis ◽

10.1154/s0376030800019558 ◽

1989 ◽

Vol 33 ◽

pp. 161-169

Author(s):

G. Sheikh ◽

I. C. Noyan

Keyword(s):

Residual Stresses ◽

Lattice Parameter ◽

Stress Profile ◽

X Ray ◽

Residual Stress Profile ◽

Cyclic Loading And Unloading ◽

Nickel Substrates ◽

Loading And Unloading

AbstractWe report the results of a recent study where nickel substrates electroplated with chromium were loaded in-situ on an x-ray diffractometer. This technique allows determination of lattice spacings in the vicinity of the interface for both the film and the substrate as a function of the applied load. We used such lattice parameter data, SEM observations of the surface and x-ray peak breadth data to study the partitioning of deformation between the film and the substrate. The data indicates progressive loss of adhesion between the film and the substrate with increasing deformation. We observe significant effect of electroplating residual stresses on the mechanical behavior of the system. The loss of adhesion between the film and the substrate coupled with the initial residual stress profile causes an apparent 'negative Poisson's ratio' for the film during initial stages of the loading. This effect disappears with cyclic loading and unloading.

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Residual Stresses for In-Situ Deposition of Thin-Film High-Temperature Superconductors

Journal of Electronic Packaging ◽

10.1115/1.2905695 ◽

1994 ◽

Vol 116 (4) ◽

pp. 249-257 ◽

Cited By ~ 9

Author(s):

P. E. Phelan ◽

M. N. Ghasemi Nejhad

Keyword(s):

Thin Film ◽

Residual Stress ◽

Residual Stresses ◽

High Temperature Superconductors ◽

Oxygen Stoichiometry ◽

Chemical Shrinkage ◽

In Situ Deposition ◽

Cell Dimensions ◽

Unit Cell Dimensions

Residual stresses are caused by nonuniform thermal expansion and chemical shrinkage taking place during processing. For thin-film high-temperature superconductors, residual stresses result because of the thermal expansion mismatch between the film and substrate, and the introduction of oxygen into the film after in-situ deposition, which makes the unit cell dimensions change (chemical shrinkage) as the oxygen stoichiometry changes. Since both the reliability of the film—especially the bond between the film and substrate—and the film critical temperature are functions of the state of stress, it is important to understand how the residual stresses vary with processing conditions. Here, a three-dimensional residual stress analysis is carried out based on laminate theory, which assumes the lateral dimensions of the entire system to be much larger than its thickness. The normal residual stress components in the film, and the peeling stress at the film/substrate interface, are calculated. The results demonstrate the crucial role that chemical shrinkage plays in the formulation of residual stresses. A large portion of the stresses arises from the initial change of the unit cell dimensions due to changes in the film oxygen stoichiometry. Therefore, the processing temperature, and especially the initial oxygen pressure in the deposition chamber, are the key variables that impact the residual stresses.

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