King Fahd University of Petroleum and Minerals

About: King Fahd University of Petroleum and Minerals is a education organization based out in Dhahran, Saudi Arabia. It is known for research contribution in the topics: Catalysis & Adsorption. The organization has 7603 authors who have published 24030 publications receiving 443803 citations. The organization is also known as: College of Petroleum and Minerals.

Density Functional Theory (DFT) modeling and Monte Carlo simulation assessment of inhibition performance of some carbohydrazide Schiff bases for steel corrosion

Abstract: DFT and Monte Carlo simulation were performed on three Schiff bases namely, 4-(4-bromophenyl)-N′-(4-methoxybenzylidene)thiazole-2-carbohydrazide (BMTC), 4-(4-bromophenyl)-N′-(2,4-dimethoxybenzylidene)thiazole-2-carbohydrazide (BDTC), 4-(4-bromophenyl)-N′-(4-hydroxybenzylidene)thiazole-2-carbohydrazide (BHTC) recently studied as corrosion inhibitor for steel in acid medium. Electronic parameters relevant to their inhibition activity such as EHOMO, ELUMO, Energy gap (ΔE), hardness (η), softness ( σ ), the absolute electronegativity (χ), proton affinity ( PA ) and nucleophilicity (ω) etc., were computed and discussed. Monte Carlo simulations were applied to search for the most stable configuration and adsorption energies for the interaction of the inhibitors with Fe (110) surface. The theoretical data obtained are in most cases in agreement with experimental results.

Plasma nitriding of Ti6Al4V alloy to improve some tribological properties

Abstract: The present study was conducted to investigate the tribological and mechanical properties of plasma-nitrided Ti6Al4V alloy. Specimens were nitrided in an H2N2 (1:8 ratio) plasma. The nitrogen concentration along the nitrided zone was obtained using the nuclear reaction analysis technique. The workpiece temperature was varied from 450 to 520 °C during the nitriding process. Pin-on-disc wear tests were carried out to evaluate the wear properties of the resultant samples and a ball-on-disc experiment was conducted to measure the friction coefficient. Microhardness tests, Scanning electron microscopy and X-ray diffraction were carried out to investigate the phases developed in the nitrided zone. It was found that the wear resistance improved considerably after the nitriding process. Three distinct layers were identified: (i) an inner layer where δ-TiN + e-Ti2N phases formed, (ii) an intermediate layer where α-(TiN) with or without e phase developed and (iii) an outer layer where precipitations were dominant.