Anti-corrosion resistance of coatings based on powder epoxy paints containing modifiers

The material property measurements of thermal bamer coatings from cyclic fumaa, thermal rig, thermal expansion, acoustic emission and tensile adhesion test methods are critically examined. Some basic engineering properties of coatings such as the elastic modulus have not been measured without ambiguity. Data of this nature is essential to the success of modeling studies. Insights into the mechanical properties of coatings have been gained by carrying out instrumented tensile adhesion tests. The general view of the coating deformation process is that the individual lamelhe slide wer each other and this promotes a pseudoductility response in the coatings. Monitoring of the acoustic emission response of coatings during thermal cycling aperiments suggests that there are two distinct cracking processes. The macrocracking behavior, indicated by a change in the acoustic emission count rate, is the predominant mechanism which leads to coating failure. It is further shown that the acceptance tests used by industry, although useful in ranking coatings in terms of a particular property, present no fundamental knowledge concerning the material properties of coatings. It is only when the phenomenological characteristics of the thermo-mechanical response of coatings is undemtood that coating development will substantially progress.

Effect of nitrogen flow rate on microstructures and mechanical properties of metallic coatings by warm spray deposition

Effect of TiO2 pigment gradation on the properties of thermal insulation coatings

Effect of Ti content on the microstructure and mechanical properties of TiAlSiN nanocomposite coatings

Composites were formed by incorporating nano, micro and hybrid-ZnO particles into the epoxy matrix at the same loading levels (3%) and applied at 90 μm thickness on the galvanized steel substrate using a film applicator in this study. The improvement in anti-corrosion performance and mechanical and physical properties of the composite coatings were evaluated using various tests and techniques such as salt-spray, electrochemical impedance spectroscopy, nanohardness, microscratch, cross-cut, bending, Fourier transform infrared spectroscopy, thermogravimetric and Scanning electron microscopy. The corrosion performance of the composite coatings near the cut edge is discussed in detail as well as on the surface of galvanized steel. The results show that the addition of all ZnO particles has a positive effect on the corrosion resistance and mechanical properties of the coatings. The addition of nano, micro and hybrid ZnO particles increased the hardness of the composites by 52, 37 and 56%, respectively, compared to the neat epoxy. Although the cathodic protection performance is weakened near the cut edge due to the loss of Zn after thermal cutting, high barrier protection was provided with composite coatings, especially micro ZnO/Epoxy composite coating.

Structure and mechanical properties of multi-principal AlCrNbSiTiON oxynitride coatings

AISI 1020 steel substrate is coated with alumina as feedstock material using plasma spraying process in order to correlate the microstructural features with mechanical properties of coating. The present work focuses on the effects of microstructural inhomogeneity on mechanical properties of alumina coating through nanoindentation technique. Young’s modulus and hardness of the alumina coating are analytically evaluated. Indentation stress–strain curves are generated from the experimentally obtained load–displacement curves to characterise the mechanical properties of the coating. The results have shown large variation in hardness and Young’s modulus of alumina due to microstructural inhomogeneity of the coating.

Stellite 6 Co-based and Hӧganӓs Fe-based alloy coatings were deposited on austenitic engine valve using plasma transferred arc (PTA) hardfacing. The microstructures, composition distribution and mechanical properties of coatings were investigated by combining optical microscope (OM), scanning electron microcopy (SEM), field emission electron-probe analyzer (EPMA) and nanoindentation technique. The microstructures of hardfacing coatings consist of three phases which belong to hypoeutectic structure and Co-based coating has more uniformed and regularly changed microstructure. The determination of mechanical properties reveals that Co-based coating attains higher hardness value (~5.229 GPa), H/E (0.0265) and H3/E*2 (0.00323) than that of Fe-based coating, signified better wear resistance property.

Multifunctional halloysite nanotube based composite coatings on titanium as metal implant for orthopedic applications

Pulsed electrodeposition, mechanical properties and wear mechanism in Ni-W/SiC nanocomposite coatings used for automotive applications

The influence of Mo target current on the microstructure, mechanical and tribological properties of CrMoSiCN coatings in artificial seawater

Characterization of gas tunnel type plasma sprayed hydroxyapatite–nanostructure titania composite coatings

This work was performed within IMI Spray Mould, an EPSRC joint funded programme, aimed at developing a manufacturing route for large aerospace composite forming tooling, based on metal spray technologies. Assesses the mechanical properties of Invar steel coatings, deposited using electric arc spraying, and correlates these properties to the spray parameters and processes used so as to offer coatings with characteristics appropriate to the tooling requirements. In particular, two processing methods, inert and air atomisation, and three arc spray gun configurations (air cap design) are evaluated. The mechanical properties of the coatings are found to be low compared to bulk Invar, regardless of the spray parameters and hardware used. Inert arc spraying affords more consistent coating characteristics but this comes with a compromised durability. The spray hardware is found to be more significant in determining the coating properties than the parameters employed.

Cr-C coatings with gradient Cr/CrN/CrCN inter-layers were studied to elucidate the effects of carbon contained on the mechanical properties and microstructures of the deposited coatings. The coatings were deposited by using a reactive sputtering system with constant total flow rate, target current and substrate bias. Percentage of C2H2flow rates were varied from 10 % to 50 %. Carbon contains in the film were measure by EDS. Mechanical properties of the coatings were evaluated with micro-indentation, scratch tester, ball-on-disk tribo-tester. Microstructures of the films were characterized by SEM, TEM, and X-ray diffractermeter. The experimental results show that carbon contain increase from 21.6 %to 99.5 % with respect to C2H2flow rates varied from 10 %, 20 %, 30 %, 40 %, 50%. And the phase of coatings change from Cr solid solution to Cr+Cr23C6+ amorphous diamond like carbon (DLC) and then to DLC +Cr7C3and then to DLC+ Cr3C2+Cr7C3. The hardness of the coatings increase with C2H2flow rate increased and achieved the maximum value of Hv1815 at 50% C2H2flow rate. The coefficient of friction decreases from 0.630 to 0.285 when C2H2flow rate increased from 10% to 50%. The wear rate decreased with increasing the C2H2flow rate.

“Effect of nano-ZnO particles on the corrosion behavior of alkyd-based waterborne coatings”