[1] Thin coatings of atmospherically deposited dust can mask the spectral characteristics of underlying surfaces on Mars from the visible to thermal infrared wavelengths, making identification of substrate and coating mineralogy difficult from lander and orbiter spectrometer data. To study the spectral effects of dust coatings, we acquired thermal emission and hemispherical reflectance spectra ...

The mechanical and tribological properties in WC-Co coatings are strongly affected by hardness and elasticity specifications. The results revealed the effect of spraying distance on microhardness and elasticity modulus of coatings. The metallurgical studies have been made on coated samples using optical microscopy, scanning electron microscopy (SEM). Keywords—Elasticity modulus, HVOF, Micro-ind...

Thermal and environmental barrier coatings are important components of current and future energy systems. Such coatings – applied to hot, metallic surfaces in combustors, heat exchanger and turbines – increase the allowable operating temperature and increase the efficiency of the energy system. Because of its low thermal conductivity and high thermal expansion yttria-stabilized zirconia (YSZ) i...

High velocity oxy-fuel (HVOF)coating have shown high resistance to corrosion in fossil energy applications and it is generally accepted that mechanical failure, e.g. cracking or spalling, ultimately will determine coating lifetime. The use of HVOF thermal spray to apply coatings is one of the most commercially viable and allows the control of various parameters including powder particle velocit...

Materials are precious resources. Different methods are employed to protect the material from degradation. Thermal spraying is one of the most effective method to protect the material from wear, high temperature corrosion, stresses and erosion, thus increasing the life of material in use. Detonation gun spraying is one of the thermal spraying techniques known for providing hard, wear resistant ...

An advanced boundary element method (BEM) is developed in this paper for analyzing thin layered structures, such as thin films and coatings, under the thermal loading. The boundary integral equation (BIE) formulation for steady-state thermoelasticity is reviewed and a special case, that is, the BIE for a uniform distribution of the temperature change, is presented. The new nearly-singular integ...

The specific outputs of some diesel engine applications have produced thermal loadings in excess of the strength of typical aluminium piston alloys. Functionally graded coatings are used to increase performances of high temperature components in diesel engines. Thermal barrier coating are being evaluated to return the components durability to acceptable levels as well as providing a means of lo...

We report on a very significant enhancement of the thermal, chemical, and mechanical stability of self-organized TiO2 nanotubes layers, provided by thin Al2O3 coatings of different thicknesses prepared by atomic layer deposition (ALD). TiO2 nanotube layers coated with Al2O3 coatings exhibit significantly improved thermal stability as illustrated by the preservation of the nanotubular structure ...

When tailored to make durable thermal barrier coatings (TBCs), the Solution Precursor Plasma Spray (SPPS) process produces a microstructure containing uniformly vertical cracks. These cracks provide a high degree of strain tolerance to the ceramic top coat. In order to understand the formation of vertical crack in SPPS process, coatings of various thicknesses were deposited on a variety of subs...

Future gravitational-wave detectors operated at cryogenic temperatures are expected to be limited by thermal noise of the highly reflective mirror coatings. Silicon nitride is an interesting material for such coatings as it shows very low mechanical loss, a property related to low thermal noise, which is known to further decrease under stress. Low optical absorption is also required to maintain...