Analytical and Numerical Modelling of Interfacial Stress Distribution of a Piezoresistive Coating Layer

2021 ◽  
Author(s):  
Adekunle Sulaimon Ogunbadejo ◽  
André McDonald ◽  
Sanjeev Chandra
Keyword(s):  
Stress Distribution ◽  
Coating Layer ◽  
Single Layer ◽  
Interfacial Stress ◽  
Insulating Layer ◽  
Thermally Sprayed Coatings ◽  
Thermally Sprayed ◽  
Monitoring Devices ◽  
Sprayed Coatings ◽  
Layer Coating

Abstract Thermally sprayed coatings can be used in structural health monitoring devices where the coatings can reveal defects in the real-time integrity of the component through changes in mechanical, thermal or modal properties during service. In this emerging application, the mechanical properties of the coating are strongly affected by the interfacial bond between the coating and the substrate. This paper presents an analytical study of the interfacial stress distribution based on piezoresistive-stress constitutive relation of a coating layer. Both a single layer coating- and a bilayer coating-substrate system were considered. An analytical solution of the interfacial stress was developed by solving a Fredholm-Volterra singular integro-differential equation of a coating-substrate model using Chebyshev polynomials. Numerical simulation was conducted to analyze the effects of geometric and effective material properties of the coating-substrate system on the interfacial stress distribution. It was found that the susceptibility of the piezoresistive layer to delamination primarily relies on thicknesses of the coating layers and the stiffness of the intermediary insulating layer and substrate.

Simplified models for residual stress prediction in thermally sprayed coatings

2008 ◽  
Vol 222 (11) ◽  
pp. 2053-2068 ◽  
Author(s):  
A M Kamara ◽  
K Davey
Keyword(s):  
Residual Stress ◽  
Layer Thickness ◽  
Coating Thickness ◽  
Interfacial Stress ◽  
Analytical Models ◽  
Elastic Behaviour ◽  
Layer Deposition ◽  
Thermally Sprayed Coatings ◽  
Thermally Sprayed ◽  
Sprayed Coatings

Residual stress in thermally sprayed coatings is known to cause a range of problems, notably debonding, cracking, and spallation. The focus in this paper is on the development of simple analytical models for the prediction of residual stress that arise from spraying a steel-alloy coating onto a copper-alloy substrate. This is a material combination that has been used recently to enhance the thermal and mechanical efficiency of the pressure die casting process although problems with debonding have been reported in the literature. Three analytical models are developed and investigated, where each represent combinations of assumptions for coating and substrate material behaviours during coating manufacture. The sensitivity of these combinations on residual stress, developed for a range of process parameters (deposited layer thickness, interval of layer deposition and the number of layers in a coating, i.e. block deposition versus multi-layer deposition for a desired coating thickness) is recorded. In agreement with experimental and finite-element modelling results from a previous study, the results from all the three models assessed in the current study indicate a progressive change in average interfacial residual stress from compressive towards tensile with an increase in the thickness of the deposited layer; and a tensile interfacial stress in a two-layer coating, which increases with an increase in the interval of deposition between the two layers. The observations from the results suggest an increase in potential for coating debonding with an increase in both deposited layer thickness and layer deposition interval. The results further suggest higher potential for coating debonding with block deposition compared with multi-layer deposition for a desired coating thickness. In terms of stress magnitudes, the model that performs best is one where the assumption that a currently deposited coating layer yields during its quenching phase and adopts elastic behaviour afterwards; and the strain generated in the substrate during the quenching phase is from thermal effect only while in the other phases afterwards, is from both thermal and elastic effects.

Thermal Spraying of High Performance Thermoplastics

1998 ◽  
Author(s):  
E. Lugscheider ◽  
C. Herbst ◽  
A. Fischer
Keyword(s):  
High Performance ◽  
Elevated Temperatures ◽  
Thermal Spraying ◽  
Paper Coatings ◽  
Thermally Sprayed Coatings ◽  
Ft Ir ◽  
Ir Analysis ◽  
Thermally Sprayed ◽  
Sprayed Coatings ◽  
Wipe Tests

Abstract Thermally sprayed coatings of high performance thermoplastics are of interest espacially for the chemical industry for anti-corrosion applications at elevated temperatures. In this paper coatings of polyetherether-keton (PEEK) and polyphenylen-sulphide (PPS) have been produced by simple flamespraying. They have been investigated by optical metallography, FT-IR analysis and DSC-analysis. Among the coating properties also the "in-flight" particles have been studied by wipe-tests and FT-IR analysis in order to assess possible decomposition effects during spraying.

Characteristics and Potential Application of Thermally Sprayed Thin Film Coatings

2000 ◽  
Author(s):  
M. Loch ◽  
G. Barbezat
Keyword(s):  
Thin Film ◽  
New Technology ◽  
Functional Coatings ◽  
Oxide Coatings ◽  
Film Coatings ◽  
Thin Film Coatings ◽  
Thermally Sprayed Coatings ◽  
Short Time ◽  
Thermally Sprayed ◽  
Sprayed Coatings

Abstract LPPS Thin Film is a new technology for the production of thin functional coatings. The coatings produced can fill the well known gap of coating thickness between conventional thin films (PVD, CVD and others) and conventional thermally sprayed coatings (Plasma, HVOF and others). The application is successful, if the advantages of the new technology (large areas can be dense coated within a very short time) are combined with the specific properties of thermally sprayed coatings to the benefit of the intended application. Beside the technology of LPPS Thin Film and it's characteristics the paper will summarise important properties of Alumina described in the literature and present some corresponding properties of Aluminium oxide coatings produced by LPPS Thin Film.

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