Evaluation of Mechanical Properties of Aluminium Alloy (Al-2024) Reinforced with Molybdenum Disulphide (MOS2) Metal Matrix Composites

AbstractThe results of an experimental investigation on the mechanical properties of molybdenum disulphide (MOS2, also called molydisulphide) powders reinforced in aluminium alloy (Al-2024) composite samples are reported in this paper. MOS2 powders of approximately 40μm particle size were reinforced in an aluminium alloy matrix to produce composite samples of ratios, 1, 2, 3, 4 & 5 weight % through stir casting technique. The fabricated composite specimens were subjected to a series of tests to evaluate the mechanical properties such as hardness and tensile strength. The same are compared with the base alloy. SEM and XRD analysis was carried out to analyze the microstructure and the dispersion of the reinforced particles in the alloy matrix. It was fairly observed from the results that, the hardness and tensile strength increased with the increase in wt. % of reinforcement particles in the matrix up to 4% addition of reinforcement and the hardness and tensile strength decreased for 5% addition of reinforcement in the matrix. The SEM and XRD results revealed the homogeneous dispersion of MOS2 particles in the matrix

Sliding wear behavior of Ti6Al4V implant alloy in the Simulated body Environment

Titanium alloys are widely used in medical applications due to their bio compatibility. Life of the implant material depends upon its wear resistance. Implants are generally placed inside the human body; Hence wear behavior was studied in the simulated body environment using Hank’s solution. Wear tests were conducted using Pin on disc wear testing machine with ASTM G-99 standard specimens. In this study, the effect of load, speed and distance on the wear behavior were experimentally investigated. Design of experiments for conducting to wear test was determined by Taguchi experimental design method. Orthogonal arrays of Taguchi, signal-to-noise ratio and analysis of variance are employed to find the optimum parameters to minimizing the wear using MINITAB-17 software. The results showed that load is the most important parameter influencing the wear. The predicted values and experimentally measured values are good in agreement and were confirmed by validating experiments

Design and Optimization of Microbial Fuel Cells and Evaluation of a New Air-Breathing Cathode Based on Carbon Felt Modified with a Hydrogel—Ion Jelly®

Funding Information: This research was funded by Fundação para a Ciência e a Tecnologia projects DSAIPA/DS/0117/2020, UIDB/04565/2020, and UIDP/04565/2020, by the Associate Laboratory Institute for Health and Bioeconomy—i4HB project LA/P/0140/2020. This work was supported by the Associate Laboratory for Green Chemistry—LAQV financed by national funds from FCT/MCTES (UIDB/50006/2020). We also thank Fundação para a Ciência e Tecnologia (FCT) for funding (SFRH/BD/77568/2011 (R.N.L.C.); SFRH/BPD/80293/2011 (R.M.A.)). C.M.C. acknowledges FCT for the Ciência 2008 Program; S.V.R. acknowledges the financial support from FCT (Portuguese Foundation for Science and Technology) for a postdoctoral research grant (FRH/BPD/33864/2009). This work was supported by the Associate Laboratory for Green Chemistry—LAQV, financed by national funds from FCT/MCTES (UIDB/50006/2020 and UIDP/50006/2020); the Institute for Bioengineering and Biosciences—iBB, financed by FCT (UID/BIO/04565/2013); and from Programa Operacional Regional de Lisboa 2020 (Project N. 007317). Publisher Copyright: © 2023 by the authors.The increased demand for alternative sustainable energy sources has boosted research in the field of fuel cells (FC). Among these, microbial fuel cells (MFC), based on microbial anodes and different types of cathodes, have been the subject of renewed interest due to their ability to simultaneously perform wastewater treatment and bioelectricity generation. Several different MFCs have been proposed in this work using different conditions and configurations, namely cathode materials, membranes, external resistances, and microbial composition, among other factors. This work reports the design and optimization of MFC performance and evaluates a hydrogel (Ion Jelly®) modified air-breathing cathode, with and without an immobilized laccase enzyme. This MFC configuration was also compared with other MFC configuration performances, namely abiotic and biocathodes, concerning wastewater treatment and electricity generation. Similar efficiencies in COD reduction, voltage (375 mV), PD (48 mW/m2), CD (130 mA/m2), and OCP (534 mV) were obtained. The results point out the important role of Ion Jelly® in improving the MFC air-breathing cathode performance as it has the advantage that its electroconductivity properties can be designed before modifying the cathode electrodes. The biofilm on MFC anodic electrodes presented a lower microbial diversity than the wastewater treatment effluent used as inocula, and inclusively Geobacteracea was also identified due to the high microbial selective niches constituted by MFC systems.publishersversionpublishe

Change in the Shape of a Molecule During the Formation of Hydrogen Bond

Evidence is found to show that C=O bond frequency dv=1710 of monochloacetic acid, the total S5rmmetric line dv=910 of sulphuric acid and the total symmetric lino 1060 of the nitrate ion in solution are found to decrease on depolymerisation due to heating, contrary to expectation. This goes against the assumptions usually made that the bond in question is unaffected by the presence of the other atoms in the molecules and the other molecules in the liquid. It is surmised that the molecules change their shape during the formation of a complex. The structure of the nitrate ion is pyramidal in solution at low temperature and it becomes plane on heating. This is taken to be a direct evidence for crystalline nature of hydration of ion in solution postulated by Lengyel

Effect of reinforcement on the cutting forces while machining metal matrix composites–An experimental approach

Hybrid metal matrix composites are of great interest for researchers in recent years, because of their attractive superior properties over traditional materials and single reinforced composites. The machinabilty of hybrid composites becomes vital for manufacturing industries. The need to study the influence of process parameters on the cutting forces in turning such hybrid composite under dry environment is essentially required. In the present study, the influence of machining parameters, e.g. cutting speed, feed and depth of cut on the cutting force components, namely feed force (Ff), cutting force (Fc), and radial force (Fd) has been investigated. Investigations were performed on 0, 2, 4, 6 and 8 wt% Silicon carbide (SiC) and rice husk ash (RHA) reinforced composite specimens. A comparison was made between the reinforced and unreinforced composites. The results proved that all the cutting force components decrease with the increase in the weight percentage of the reinforcement: this was probably due to the dislocation densities generated from the thermal mismatch between the reinforcement and the matrix. Experimental evidence also showed that built-up edge (BUE) is formed during machining of low percentage reinforced composites at high speed and high depth of cut. The formation of BUE was captured by SEM, therefore confirming the result. The decrease of cutting force components with lower cutting speed and higher feed and depth of cut was also highlighted. The related mechanisms are explained and presented