Search results for "Polymer substrate"
showing 5 items of 5 documents
Evaluation of interfacial stress transfer efficiency by coating fragmentation test
2007
Probabilistic model of coating fragmentation under uniaxial tensile loading is developed. Analytical expressions of the crack spacing evolution are obtained for small-strain and large-strain fragmentation regimes. The model is applied for coating and interface property identification of several thin brittle coating/polymer substrate systems. An estimate of the stress transfer length, derived from the fragmentation data, is found to correlate with the interfacial shear strength thus suggesting that both parameters reflect an intrinsic property related to the mechanical efficiency of coating/substrate interface.
<title>Properties of ITO transparent electrode thin films on different substrates</title>
2003
Indium tin oxide (ITO) is optically transparent semiconductor that finds extensive applications in liquid crystal displays, photovoltaic cells, touch screen displays, electrochromic smart windows and more. As with all such electrode materials, there is a compromise between conductivity and optical properties. Different substrate materials and underlying layers are playing important role in transparency (better contrast and less absorption, increased brightness), surface morphology (smoothness, homogeneously) and conductivity of the ITO films. We compared optical, electrical and morphology properties of ITO films onto polymer substrate, obtained from company "SIDRABE Inc." (Latvia) and ITO f…
Advanced fragmentation stage of oxide coating on polymer substrate under biaxial tension
2005
Crack patterns of 100-nm-thick silicon oxide coating on polypropylene film subjected to equibiaxial stress loading are studied experimentally. The loading is achieved by means of a bulging cell mounted under an optical microscope with stepwise pressurization of film specimens. The evolution of the coating fragment area distribution at relatively high strains is modeled using Weibull statistics to describe the coating strength. The fragment area distribution at an advanced fragmentation stage is shown to scale with the average fragment area, the latter being a power function of the applied biaxial strain.
Estimation of interfacial fracture toughness based on progressive edge delamination of a thin transparent coating on a polymer substrate
2010
Evaluation of interfacial toughness of sub-micron-thickness layers deposited on a ductile substrate is a challenging task which has motivated different experimental approaches Fragmentation testing was used in the present study as a means of interface characterization of a silicon-nitride-coated polyimide substrate. During the test, after an initial rapid segmentation-cracking phase, the coating fragments developed edge delaminations which propagated in a stable manner with further increase in the applied strain The debonding process was modelled by the finite element method Incorporating a cohesive zone at the front of the interfacial crack The edge cracks were found to be dominated by mod…
Analysis of thin film cracking and buckling on compliant substrate by fragmentation test
2007
Application of coating fragmentation test for determination of coating properties is considered. A probabilistic model of coating fragmentation under uniaxial tensile loading is applied for coating and interface property identification of thin brittle coating/polymer substrate system. A finite element model is developed to simulate the process of buckle formation in coating strips during fragmentation test. The measured buckle geometry parameters and buckle density evolution as a function of the applied strain is used to estimate the interface toughness.