Maximising the interfacial toughness of thin coatings and substrate through optimisation of defined parameters
Authors: Nazir, M.H. and Khan, Z.
Journal: International Journal of Computational Methods and Experimental Measurements
Volume: 3
Issue: 4
Pages: 316-328
eISSN: 2046-0554
ISSN: 2046-0546
DOI: 10.2495/CMEM-V3-N4-316-328
Abstract:The influence of three parameters, i.e. interfacial roughness λ, coating thickness h and impurity radius r at the coating-substrate interface on interfacial toughness, has been investigated within the framework of two approaches, i.e. thermodynamics and fracture mechanics. The governing equations for both the approaches have been derived independently and then fused to form a governing law for evaluating the interfacial toughness. The analysis in this paper which considers three parameters (λ, h and r) has been divided into three setups. Each setup is used to analyse the effect of one variable parameter on interfacial toughness while keeping the other two parameters constant. Three samples for each setup were prepared considering the requirements of constant and variable parameters for each setup. Simulation techniques founded on the experimental studies have been developed during this research in order to find the optimised values of three parameters. These optimised values act as critical values (boundary point) between coating fail-safe and coating fail conditions. The experiment employed ASTM-B117 test, which is used to analyse the interfacial toughness of samples under each setup. These experiments showed excellent, quantitative agreement with the simulation trends predicted by the theoretical model.
https://eprints.bournemouth.ac.uk/22020/
Source: Scopus
Maximising the Interfacial Fracture Toughness of Thin Coatings and Substrate through Optimisation of Defined Parameters
Authors: Khan, Z. and Nazir, M.H.
Conference: Contact and Surface 2015
Dates: 20-24 April 2015
Publisher: WIT
Abstract:The influence of three parameters i.e. interfacial roughness, coating thickness and the size of impurity at the interface on interfacial fracture toughness has been investigated within the framework of two approaches i.e. thermodynamics and fracture mechanics. Mathematical relationship for both the approaches have been designed independently and then fused to form a governing law for evaluating the interfacial toughness. Simulation techniques founded on the experimental studies, have been developed during this research in order to find the optimised values of three parameters. These optimised values act as critical values (boundary point) between coating fail-safe and coating fail conditions and can be used to avoid coating failure due to loss of interfacial toughness. The experimental design considering three parameters has been divided in to the three setups. Each setup is used to analyse the effect of one variable parameter on interfacial toughness while keeping the other two parameters constant; (i) Setup 1: Constant coating thickness and constant impurity size with variable roughness (ii) Setup 2: Constant roughness and constant impurity size with variable coating thickness (iii) Setup 3: Constant coating thickness and constant roughness with variable impurity size. Three samples for each setup were prepared considering the requirements of constant and variable parameters for each setup. ASTM-B117 salt spray (fog) test methodology was deployed for conducting experiments. Conditioned samples were exposed to simulated environment in the test chamber for up to 150 hrs. Experimental observations were recorded every 24hrs. The effect of ASTM-B117 test environment on interfacial toughness of coated samples under each setup has been studied using 3D- surface interferometry, scanning electron microscopy (SEM) and micro-indentation techniques. These experiments showed excellent, quantitative agreement with the simulation trends predicted by the theoretical model.
https://eprints.bournemouth.ac.uk/22020/
http://www.wessex.ac.uk/15-conferences/contact-and-surface-2015.html
Source: Manual
Preferred by: Zulfiqar Khan
Maximising the Interfacial Fracture Toughness of Thin Coatings and Substrate through Optimisation of Defined Parameters
Authors: Khan, Z.A. and Nazir, M.H.
Conference: Contact and Surface 2015: 12th International Conference on Computational Methods and Experiments in Surface and Contact Mechanics including Tribology
Publisher: WIT Press
Abstract:The influence of three parameters i.e. interfacial roughness, coating thickness and the size of impurity at the interface on interfacial fracture toughness has been investigated within the framework of two approaches i.e. thermodynamics and fracture mechanics. Mathematical relationship for both the approaches have been designed independently and then fused to form a governing law for evaluating the interfacial toughness. Simulation techniques founded on the experimental studies, have been developed during this research in order to find the optimised values of three parameters. These optimised values act as critical values (boundary point) between coating fail-safe and coating fail conditions and can be used to avoid coating failure due to loss of interfacial toughness. The experimental design considering three parameters has been divided in to the three setups. Each setup is used to analyse the effect of one variable parameter on interfacial toughness while keeping the other two parameters constant; (i) Setup 1: Constant coating thickness and constant impurity size with variable roughness (ii) Setup 2: Constant roughness and constant impurity size with variable coating thickness (iii) Setup 3: Constant coating thickness and constant roughness with variable impurity size. Three samples for each setup were prepared considering the requirements of constant and variable parameters for each setup. ASTM-B117 salt spray (fog) test methodology was deployed for conducting experiments. Conditioned samples were exposed to simulated environment in the test chamber for up to 150 hrs. Experimental observations were recorded every 24hrs. The effect of ASTM-B117 test environment on interfacial toughness of coated samples under each setup has been studied using 3D- surface interferometry, scanning electron microscopy (SEM) and micro-indentation techniques. These experiments showed excellent, quantitative agreement with the simulation trends predicted by the theoretical model.
https://eprints.bournemouth.ac.uk/22020/
http://www.wessex.ac.uk/15-conferences/contact-and-surface-2015.html
Source: BURO EPrints