In various industries such as power plants, ultrasonic non-destructive testing (NDT) is widely used because of cost effectiveness and sub-surface defect/flaw detection capability. Piezoelectric films made of sol-gel composites could be useful as ultrasonic transducers due to high tempearature durability, reasonable signal strength, curved surface suitability, relatively low center frequency suc...

We study laser irradiation behavior of multiwalled carbon nanotubes (MWCNT) and chemically modified graphene (rGO)-composite spray coatings for use as a thermal absorber material for high-power laser calorimeters. Spray coatings on aluminum test coupon were exposed to increasing laser irradiance for extended exposure times to quantify their damage threshold and optical absorbance. The coatings,...

Cold spray coatings are considered promising for surface protection of light metal substrates but the mechanisms of bonding and coating build-up are still poorly understood and are the subject of continuing debate. A variety of coating/substrate combinations have been characterised in detail using electron microscopy to examine the nature of the interparticle and particle/substrate interfaces. ...

Abstract Impact spreading of droplets in spray coating of paper was investigated using numerical simulation based on a volume-offluid (VOF) model. The results include the effects of droplet size, droplet impact velocity, liquid viscosity, liquid surface tension and paper web velocity on droplet spreading. Pressure and strain rate fields as well as timescales of spreading are reported. The resul...

The microstructure and local mechanical characteristics of thermal spray ferrous coatings have been determined. The emphasis has been on coatings made by the high velocity oxyfuel (HVOF) process, especially the role of Al alloy additives. The oxide phase present in the material and preferred pathways for local cracking and separation have been determined. Thin intersplat oxide layers emerge as ...

Thermally processed hydroxyapatite coatings used on dental implants and hip prostheses for enhanced fixation may typically consist of a number of chemical and structural phases. These phases affect coating performance and tissue attachment. Hydroxyapatite was plasma sprayed to examine the phase evolution during processing. Coatings were examined with X-ray diffraction and elemental analysis. Re...

During the process of thermal spray coating, molten powders are sprayed and deposited on substrates to generate protective coatings. It is essential to have a clear understanding of the physics of droplet impingement on the surface of substrates for better control of the generation of splats and the structure of coating. A numerical model is developed in this paper to simulate the dynamics of t...

Solid Oxide Fuel Cells (SOFCs) are electrochemical conversion devices that produce electricity directly by oxidising a fuel. The interconnects between the individual cells need to be coated limit Cr(VI) evaporation from steel and preserve electrical conductivity. Physical Vapour Deposition (PVD)-coated samples with Ce/Co, Ce/Cu, Ce/MnCu, Thermal Spray (TS)-coated Mn/Co, Cu Mn/Cu AISI 441 were e...