Coatings control corrosion by providing a barrier against oxygen and water. Although coatings are extremely effective, all organic coatings are semi-permeable to O2 and water. The water permeability coefficient of fusion bonded epoxies, one of the best coating systems, is approximately 10 gms/mil/24 hours, but minimum concentration of oxygen and water that can start the corrosion process is 10 ...

This paper discusses two common problems, “weld tenting” and low coating thickness over the external weld, and their causes in traditional three layer polyolefin pipeline coatings. To tackle these problems, a new approach to applying multilayer polyolefin coating to pipes is introduced. The new system consists of side-extruding high density polyethylene over a graded structure polyethylene (GSP...

 In this research, a numerical modeling was utilized to calculate the stresses caused during thermal cycling in a functionally graded thermal barrier coating (FG - TBC). The temperature – dependent material response of this protective material was taken into account and the effects of thermal cycle and interface morphology of the ceramic / metallic layer in functionally graded coating system wa...

The application of a few basic principles, some empirical data, and experience is applied to estimate the average residual reflection expected in an AR coating as a function of bandwidth, wavelength, overall thickness, substrate index, available coating materials, and number of layers. This can be a useful tool for not only the thin film designer but also the non-designer or system engineer to ...

The infrared thermography (thermal imaging) is considered a flexible, non-contact, and non-destructive tool used to evaluate wide variety of coating attributes (e.g. appearance and protective attributes). This paper addresses the application of thermographic systems in evaluating the protective-coating coverage over steel substrates in two different painting industries. First case is the inspec...

A near-infrared spectroscopic method and measurement system for moisture depth profiling is presented in this thesis. The measurement system is based on a fibre-optic light source and probes, and a hyperspectral imaging spectrograph. The probes feature six different measurement geometries, including a specular reflection measurement, and diffuse reflection and transmission measurements, all of ...