Effect of coating thickness on properties of Mo coatings deposited by plasma spraying

Plasma sprayed molybdenum coatings with different coating thicknesses (100, 200, 300 and 400 μm) were deposited on steel substrate. The variation in microstructural characteristics and properties of coatings with various thicknesses was investigated. The microhardness was measured using a Vickers’ indenter. The quantitative investigation of porosity is carried out with the help of computerised image analyser. The influence of coating thickness on wear resistance was estimated using pin on disc wear test rig. The worn surface of coated pin was characterised by scanning electron microscopy. The experimental results indicated that porosity of coating was increased with increased coating thickness. The enhanced coating thickness also resulted in decreasing microhardness and reduced wear resistance. In this study, the plasma sprayed thin coating with thickness of 100 μm possesses the lowest porosity, the highest hardness and better wear resistance.     

Effect of temperature and electron irradiation on the I–V characteristics of Au/CdTe Schottky diodes

The results of the studies on the effect of temperature and 8 MeV electron irradiation on the current–voltage (I–V) characteristics of the Au/CdTe Schottky diodes are presented in this article. Schottky diodes were prepared by evaporating Au onto n-type CdTe films electrodeposited onto stainless steel substrates. The forward and reverse current–voltage characteristics of these diodes were studied as a function of temperature. The diodes were subjected to 8 MeV electron irradiation at various doses and their effect on the I–V characteristics was studied. Some intrinsic and contact properties such as barrier height, ideality factor, and series resistance were calculated from the I–V characteristics. Diode ideality factor of the junctions were greater than unity. The ideality factor and the series resistance R_s increase with decrease in temperature. The conduction seems to be predominantly due to thermionic emission–diffusion mechanism. The resistance was found to increase with increasing dose. The leakage current, ideality factor and barrier height were found to be unaffected by electron irradiation up to, a dose of about 40 kGy.     

Investigating the Effect of Si3N4 Reinforcement on the Morphological and Mechanical Behavior of AA2219 Alloy

Silicon - The present investigation aims to investigate the mechanical, metallurgical and morphological study of Aluminium Alloy AA2219 reinforced with various percentage of Si3N4 (0,3,6 and 9)...     

Application of Bernoulli wavelet method on triple-diffusive convection in Jeffery–Hamel flow

In this article, triple-diffusive convection in the Jeffery–Hamel flow of viscous fluid is studied. The Jeffery–Hamel flow depends upon the radial component of velocity, while the peripheral velocity is zero. The problem has been articulated as nonlinear coupled partial differential equations (PDEs) together with the pertinent boundary conditions. The reduction of the nonlinear coupled PDEs into new nonlinear coupled ordinary differential equations is achieved via a collection of appropriate transformations, which is solved using the Bernoulli wavelet method. The obtained results were compared with the numerical results, confirming the good agreement between the present and previous numerical results. Dimensionless velocity, temperature, and concentration profiles are discussed for the relevant factors involved. Furthermore, skin friction, heat transfer, and solute diffusions are calculated.