Papers by Keyword: Weight Percentage

Abstract: Magnetorheological (MR) grease is a promising material to replace MR fluid because the advantage in term of stability and less possibility to leaking. To improve the material properties, an accurate model can be critical for reducing the time and cost of the development process. A model has been developed to predict MR fluid material properties by including the composition. However, the model may need adjustment and cannot predict other essential rheology parameters, such as viscosity, apparent viscosity, shear rate, and shear stress. Therefore, the technical novelty of this paper is to propose a model with composition as one of the inputs using extreme learning machine method. A scoring system is also introduced to quantify the significance of the composition effect toward the MR grease performance. Then, the model is simulated and compared with experimental data. The performance shows high accuracy estimation with normalized root mean square error about 1.25%.

Abstract: The generation of heat during machining at the cutting zone adversely affects the surface finish and tool life. The heat at the cutting zone, which plays a negative role due to poor thermal conductivity, resistance to wear, high strength at high temperatures and chemical degradation can be overcome by the use of proper lubrication. Advancements in the field of tribology have led to the use of solid lubricants replacing the conventional flood coolants. This work involves the use of nanoparticulate graphite powder as a lubricant in turning operations whose performance is judged in terms of cutting forces, tool temperature and surface finish of the work piece. The experimentation revealed the increase in cutting forces and the tool temperature when the solid lubricant used is decreased in particle size. The surface finish deteriorated with the decrease in particle size of the lubricant in the nanoregime. Keywords-Turning, Solid lubricant, Graphite, Minimum Quantity Lubrication, nano–particles, Weight percentage , Friction coefficient.

Abstract: Finding on the one-dimensional purified aligned carbon nanotubes (ACNT) was prepared using botanical hydrocarbon: camphor powder in a two-stage catalytic chemical vapor deposition will be presented. For the first time, the hydrocarbon source and catalyst were patterned in different alumina boats in the system. The growth of ACNT has achieved free standing formation with higher aspect ratio. In contrast, unpurified carbon nanotubes have some drawbacks and require some treatments to fully utilize their capabilities in various applications. The results reveal that the crystallinity and purity of functionalized align carbon nanotubes was increased after wet-chemical technique and heat treatment process. In this paper, the results provide evidence showing that it was in good agreement with the field emission scanning electron microscopy, micro-Raman and thermogravimetric analysis.

Abstract: The pin on disc (POD) tests revealed an inverse relationship between coefficient of friction and the particle size of boric acid. So, as the properties of materials are changing with respect to its spatial dimension, the tribological performance of solid lubricant in the metal cutting is a matter of research. The present work aims at investigating the effect of variation of particle size of boric acid in the nano level in the machining of hardened steel. Canola oil and SAE 40 oil are tested as the carrying media for nano crystalline boric acid. In both cases, all the machining parameters viz. cutting forces, tool temperatures and surface roughness increased with the decrease of the particle size in nano level. The effect of carrying medium is also targeted and SAE 40 oil has been found as the best.