Search

In this present investigation, novel hybrid magnesium composites were synthesized by the inclusion of self-lubricating (BN/MoS 2) and ceramic (ZrO 2) particulates with the help of the powder metallurgy technique. ZE41 magnesium (Mg–4Zn-1RE-0.7Zr) was applied for a broad range of components, including the gearbox casing, the framework of the door, and transmission in aircraft like the Sikorsky UH-60 and the Boeing 727. Apart from its structural application, its usage was limited because of its deficient wear and mechanical properties. This research focuses on enhancing the potential applications of the ZE41 magnesium alloy by improving its mechanical and tribological characteristics. The design of the experiment scheme was applied to explore the effect of individual reinforcements and their synergistic effects on various properties of prepared composites. Microstructural inspection was employed to inspect the morphological characteristics of prepared specimens through scanning electron microscope (SEM) and Energy-dispersive X-ray spectroscopy (EDS) and X-ray diffraction analysis (XRD). By analysing SEM, EDS, and X-ray diffraction patterns, the microstructural evaluation reveals uniform phase dispersion and the existence of reinforcements with some minor defects. As a result of the inclusion of reinforcements in composites, the hardness of the reinforced specimen improved to 39.65%, while the wear rate of the reinforced specimen decreased to 40.90% compared with monolithic alloy. A multi-objective grey relational analysis (GRA) optimization method was used to perform a detailed tribological analysis on Specimen G (ZE41 mg + 3% ZrO 2 + 3% MoS 2). According to the results of GRA, the optimized rate of wear and frictional coefficient were achieved on sliding velocity (4 ms−1), sliding distance (2000 m), and load (10 N). The worn surface micrograph reveals that the reinforced composite underwent abrasion and delamination wear, while the unreinforced alloy experienced plastic deformation. [ABSTRACT FROM AUTHOR]

The manufacturing sector is among the fastest growing in today's industrialized world. Increasing the efficiency and sustainability of manufacturing processes is one way to improve productivity and improve profit margins. Learning about cutting conditions and how they affect machined surfaces and tool life can help improve productivity. This research aims to analyze the machinability of difficult-to-cut magnesium alloys through lubrication and different cooling strategies and their influence on the environment. Flank wear, chip morphology, tool contact length, and surface roughness were all measured in this study using controlled machining experiments with dry and vegetable oil mist cutting conditions and coated carbide tools. To improve the machinability of magnesium alloys, researchers looked at surface roughness, tool wear processes, and primary and secondary machining components such as effective shear angle, compression ratio, and coefficient of friction. In this study, we found that minimum quantity lubrication (MQL) performed well under various speed ranges for coated tools. Tool wear, surface roughness, and other output response characteristics were significantly connected to feed rate and cutting speed. MQL improved the surface finish and material removal rate by 20% compared to dry machining, and microhardness has been improved by 11.5%. MQL-based systems offer great potential to improve the machinability of magnesium alloys, and they should be explored further. [ABSTRACT FROM AUTHOR]

Laser cladding (LC) is mostly employed to enhance the wear resistance of magnesium alloy substrates. Adding nanoparticles will further strengthen the tribo surface properties, making them suitable for applications requiring lightweight components. This work investigated a dry sliding wear analysis for the laser-cladded AZ61 magnesium alloy with TiO2 nanoparticles at different volume ratios through the LC method. The spatial dispersion of the TiO2 nanoparticles in the AZ61 magnesium alloy microstructure was analyzed using scanning electron microscopy (SEM). The reinforcement ratio, sliding speed, and normal load were selected to study the tribo performance of the cladded surface. Coefficient of friction (COF) and wear loss analyses were performed using a pin on the disc dry sliding wear test. The effect of dry sliding variables on reinforcement ratio was analyzed with an orthogonal array experimental design. Grey relational analysis (GRA) studied multiple wear test responses to reveal optimal conditions to decrease the wear and friction coefficient of the AZ61 laser cladded surface. The reinforcement percentage of nanoceramic TiO2 particles in the AZ61 alloy surface was the most significant factor, contributing 97.76%, followed by a contribution of 0.26% by sliding speed and a normal load of 1.82%, confirmed with the grey relational grade. Both SEM and GRA confirmed that the reinforcement ratio of 10% exhibited lower wear loss and friction coefficient. The revealed wear mechanism operating on the worn surface of laser-cladded AZ61 magnesium alloy was micro-grooving exerted by a counter surface at all sliding conditions. This study shows that the LC of magnesium alloys will be preferred in sliding seal and lightweight gear applications. [ABSTRACT FROM AUTHOR]

In this work, the authors investigate the optimal tribological parameters of Al 7075 composite reinforced with ZrB2 using Grey Relational Analysis (GRA). Initially, the composite specimens were prepared by the variation of reinforcement 5%, 10% and 15% using stir casting routing method. Further, the developed metal matrix composites are used to measure the wear and frictional properties on pin-on - disc testing apparatus. The input parameters such as, wt% of reinforcement (5%, 10% and 15%), load (4.92N, 9.81N and 14.72N) and the time required for conducting the wear test is (15 min. 30 min and 45 min). A Taguchi L9 orthogonal array was designed for conducting the number of experiments. Based on the combination of number of experiments wear study has been conducted on the wear testing apparatus. Moreover, GRA was used for obtaining the best optimal input control parameters that gives minimum magnitude of wear and coefficient of friction (COF). Finally, the confirmatory experiments are conducted and verified with the Taguchi grey relational analysis. The results shows that the predicated optimal mean value is almost similar to the experimental value. [ABSTRACT FROM AUTHOR]

The present study examines the cutting of X210Cr12 cold work tool steel by a triple (CVD) coated carbide tool (Al2O3/TiC/TiCN). This is an experimental investigation followed by modeling and optimization inherent to the cutting process of the above material. The first part of this work deals with carrying out experimental tests to evaluate the effects of cutting parameters on the flank wear (Vb) evolution and workpiece surface topography including 2D and 3D functional parameters. In the second part, a Taguchi L16 (4^3 2^1) design of experiment was adopted to optimize cutting conditions. For that, a single objective optimization based on Taguchi analysis using the signal/noise (S/N) ratio was performed. In addition, multi-criteria optimization was conducted by (GRA, MOORA, DEAR, WASPAS) methods using the (S/N) report. The desired objective corresponds to the minimization of Ra, Fz, and Pc and the maximization of MRR. A comparison between the optimal regimes found by the different methods used has been analyzed and discussed. Finally, confirmation tests were conducted to determine the results of the optimal regimes obtained outside the experimental design. [ABSTRACT FROM AUTHOR]

Rubber reinforced by nanofillers has high mechanical and frictional properties and has been considered a promising tire material for future applications. However, due to its potential environmental risks, particulate matter emission induced by the wear of this tire material should be evaluated. In this study, the wear particulate matter (WPM) induced by tire rubber reinforced by graphene (Gra) and carbon nanotubes (CNTs) against a concrete surface was investigated utilizing a self-developed rolling contact test rig. The results show that the addition of appropriate Gra and CNT contents can reduce WPM emission. Rubber with Gra and CNTs emits more WPM with a size of 3.0 (WPM 3.0) in the same worn mass. CNTs play an important role in the emission of WPM 3.0. A greater worn amount does not always lead to a higher WPM 3.0 per unit of worn mass. The WPM 3.0 and 10.0 emissions per unit of worn mass are most governed by variations in velocity and load, respectively. The results from the present study may be useful in evaluating the potential environmental threat of nanofiller-reinforced rubber. [Display omitted] • Graphene and CNTs hybrid fillers reinforced rubber emits more WPMs 3.0. • CNTs play the governing role in the WPMs 3.0 emission. • A greater rubber worn doesn't always lead to higher WPMs3.0 per unit of worn mass. • WPMs 3.0 and 10.0 per unit worn mass are most influenced by velocity and load variation, respectively. [ABSTRACT FROM AUTHOR]