Study the Effect of Aluminum Variation on Hardness & Aluminum Loss in Zn-Al Alloy
The objective of this research is to study the hardness &aluminiumloss with percentage variation in Aluminium content added to zinc. As there is a method for coating known as Galfan is available, in which combination of 95%zinc and 5% Aluminium is used for protecting steel from corrosion.As there are not much details available about why this composition is used Zinc-5%Al, we are interested in study of effects of different composition of Aluminum with Zinc, so we study the effect by adding different composition 2.5%,4.5%,6.5%,8.5% & 11.5% Aluminum in Zinc, for this study we are using hot dip galvanizing process for studying this coating. Hot-dip galvanizing is widely used to improve the corrosion resistance of steel. To obtain high-quality coatings, some alloy elements are added to the zinc bath. Aluminum is one of the most important elements in galvanizing.Fe-Al phase diagram indicated thatα Fe is obtained between 1 to 11% of AluminiumGalfan alloy consist of 95% Zn and 5% Al. It was decided to study the effect of variation in Al content in ZincAluminium alloy .Also during melting of this alloy we wanted to observed loss of Al due to oxidation hence the above compositions were decided.
Evaluación de propiedades mecánicas en recubrimientos galvanizados por doble inmersión en caliente sobre acero al carbono
Poco se conoce sobre las condiciones operacionales, la microestructura y propiedades de los recubrimientos fabricados por doble inmersión en caliente. Este trabajo tiene como objetivo evaluar propiedades mecánicas de recubrimientos Zn/Zn-5%Al aplicados por la técnica de doble inmersión en caliente, variando los tiempos de inmersión en los baños líquidos. Para la evaluación se realizaron perfiles de microdureza Vickers y ensayos de doblez. Los perfiles de microdureza para diferentes tiempos de inmersión presentan similitudes, mostrando gran heterogeneidad debido a las características microestructurales. Se observa que al aumentar el tiempo de inmersión disminuye el ángulo crítico y el tiempo de inmersión no influye significativamente en la densidad de grietas confinadas y no confinadas. Se concluye que la ductilidad de los recubrimientos se ve influenciada por el espesor total de los mismos, y posiblemente por el espesor de las diferentes zonas y esfuerzos residuales, siendo las muestras recubiertas con tiempo de inmersión de 60 segundos, las que presentan mejor comportamiento ante el ensayo de doblez.
CFD simulation of hydrodynamics and heat transfer in gas phase ethylene polymerization reactors
Abstract The hydrodynamics and temperature of a two-dimensional gas–solid fluidized bed of gas phase olefin polymerization reactor had been studied. A two-fluid Eularian Computational Fluid Dynamics (CFD) model with closure relationships according to the kinetic theory of granular flow has been applied in order to simulate the gas–solid flow. Fluidization regime and gas–solid flow pattern were investigated using three different drag models. Model predictions of bed pressure drop were compared with corresponding experimental data reported in the literature to validate the model. The predicted values were in reasonable agreement with the experimental data. The temperature behavior of fluidized bed with various drag models was investigated. The temperature gradient in the primary section of the bed was much larger than the gradient in other sections and the effect of all drag models on temperature gradient along the bed was approximately similar.