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Devices of solar water desalination confront many problems including the low thermal properties of phase change materials (PCMs) such as heat transfer, storage of heat capacity, charging and discharging capability. Thus, these properties need to be improved by using a simple and novel procedure. So, incorporation and dispersion of hybrid nano-powders inside PCMs is considered a simple and novel procedure to improve the thermal properties of solar water desalination devices. The present article is focused on incorporating different nano-powders of MWCNTs and Al2O3 inside PCMs to improve the thermal characteristics of solar water desalination applications. Different nano-powders of MWCNTs and Al2O3 have been incorporated as: (i) 1.0 mass% Al2O3, (ii) 1.0 mass% MWCNTs, and (iii) hybrid 1.0 mass% of Al2O3 + 1.0 mass% MWCNTs, inside a constant amount of 250 gm RT-65HC paraffin wax. An innovative prototype was designed and produced to measure the thermal characteristics of solar water desalination devices. Various analyses have been carried out to study the influence of nano-powders scattering on the morphological, microstructural observations, chemical and thermal characteristics, including SEM, XRD, FT-IR, TGA, DSC, thermal conductivity, and infrared thermography. Microstructural observations showed that the excellent dispersion of nano-powders was at hybrid nano-additives of 1.0 mass% MWCNTs + 1.0 mass% Al2O3 inside PCMs. The uniform scattering of hybrid 1.0 mass% MWCNTs + 1.0 mass% Al2O3 inside PCMs assists to eliminate any defects. Finally, thermal characteristics of hybrid nano-additives phase change materials (NAPCMs) were improved specially in thermal stability, latent heat temperature, and thermal conductivity at 89%, 80%, and 32.8%, respectively. [ABSTRACT FROM AUTHOR]

A356 hypoeutectic aluminum-silicon alloys matrix composites reinforced by different contents of multiwalled carbon nanotubes (MWCNTs) were fabricated using a combination of rheocasting and squeeze casting techniques. A novel approach by adding MWCNTs into A356 aluminum alloy matrix with CNTs has been performed. This method is significant in debundling and preventing flotation of the CNTs within the molten alloy. The microstructures of nanocomposites and the interface between the aluminum alloymatrix and theMWCNTs were examined by using an optical microscopy (OM) and scanning electron microscopy (SEM) equipped with an energy dispersive X-ray analysis (EDX). This method remarkably facilitated a uniform dispersion of nanotubes within A356 aluminum alloy matrix as well as a refinement of grain size. In addition, the effects of weight fraction (0.5, 1.0, 1.5, 2.0, and 2.5 wt%) of the CNT-blended matrix on mechanical properties were evaluated. The results have indicated that a significant improvement in ultimate tensile strength and elongation percentage of nanocomposite occurred at the optimal amount of 1.5wt%MWCNTs which represents an increase in their values by a ratio of about 50% and 280%, respectively, compared to their corresponding values of monolithic alloy. Hardness of the samples was also significantly increased by the addition of CNTs. [ABSTRACT FROM AUTHOR]

High-density polyethylene (HDPE) and different weight fractions of multi-wall carbon nanotubes (MWCNTs) in the weight fraction of 1, 2, 3, and 5% were successful fabricated using magnetic stirring-twin screw extrusion and subjected to wear tests at two load variations maintaining a fixed speed. Three wt. % MWCNTs/HDPE nanocomposites exhibited the best tribological performance, so this composition was selected to develop hybrid nanocomposites with the addition of 0.6, 1.2, 1.8, 2.4, and 3 wt % Nano-alumina particles. Three wt. % MWCNTs+1.2 wt % Al 2 O 3 /HDPE nanocomposites outperformed other compositions and exhibited leading tribological performance and the lowest friction coefficient attributed to creating stable, coherent, and adherent transfer film. MWCNTs and Al 2 O 3 reinforcement mutated the wettability (from contact angle of ~93° ± 2°–~116.6° ± 3°) and surface energy (from ~25 to ~17.6 mN/m) of nanocomposites compared to pure HDPE. Investigations on electrical properties revealed that the conductivity remained unaffected up to 2 wt % of MWCNTs. Three wt. % MWCNTs/HDPE nanocomposites marked a sharp increase in the conductivity up to a frequency of 4.75 × 106 Hz, after which it decreased and followed the same trend as pure HDPE, and 1, 2 wt % nanocomposites. The permittivity of the nanocomposites increased with the increment in wt. % of MWCNTs at low frequency, and beyond a critical frequency, it became frequency independent. The percolation threshold of MWCNTs/HDPE nanocomposites appeared between 2 and 3 wt %. • Novel HDPE composites incorporating MWCNTs and Nano Al 2 O 3 were prepared in different compositions. • MWCNTs/HDPE nanocomposites exhibited superior electrical conductivity. • MWCNTs with Al 2 O 3 reinforcements significantly altered the polar and dispersion fractions. • Wettability decreased with Al 2 O 3 and MWCNTs reinforcement, exhibiting strong hydrophobicity. • Three wt. % MWCNTs/1.2 Al 2 O 3 loading reduced the wear rate by more than 50%. [ABSTRACT FROM AUTHOR]

Purpose The purpose of this paper is to investigate the rheological characteristics of graphene nanoplatelets (GNPs) and hybridized nanocomposite consisting of multi-walled carbon nanotubes (MWCNTs) and GNPs as an additive on lithium-based grease. The experiments of nanogrease are examined in different values of shear stress, apparent viscosity, temperature and shear rate using Brookfield Programmable Rheometer DV-III ULTRA and characterized by high-resolution transmission electron microscope (HRTEM) and X-ray diffraction (XRD).Design/methodology/approach First, GNPs was mixed well with lithium grease using mechanical stirring at 3,500 rpm for 15 min at room temperature to form a homogenous composite at different concentrations (0.5, 1, 1.5, 2 and 2.5 Wt.%). Afterwards, MWCNTs and GNPs are mixed and dispersed well in the lithium grease using a sonication path for 30 min and mechanical stirring at 3,500 rpm for 15 min at 28°C to form a homogenous nanocomposite.Findings The results indicated that 1 Wt.% of GNPs is the optimum concentration. Subsequently, the weight percentage of additives varying between MWCNTs and GNPs are tested, and the result indicate that the grease containing GNPs had a 75 per cent increase in shear stress and 93.7 per cent increase in apparent viscosity over ordinary grease.Originality/value This work describes the inexpensive and simple fabrication of nanogrease for improving properties of lubricants, which improve power efficiency and extend lifetimes of mechanical equipment. [ABSTRACT FROM AUTHOR]

The present work studies the effect of iron on the microstructural characterization and mechanical properties of Ti12Mo6ZrxFe alloys that fabricated by two different techniques elemental blend (EB) at 600 MPa and mechanical alloying (MA) at 600 MPa and 900 MPa with different sintering temperatures. The Ti12Mo6Zr x Fe ( x = 1, 2, 3 and 4 wt.%) alloys were investigated to develop new biomedical materials used for dental implant application. The microstructure, residual porosity and the mechanical properties of the sintered Ti12Mo6Zr x Fe alloys were investigated by using optical microscopy, X-ray diffraction (XRD), Scanning Electron Microscopy (SEM(, Energy dispersive X-ray (EDX), microhardness and bending stress–strain curves. The results indicated that addition of Zr and a small amount of Fe improves the β-phase stability and improving the properties of Ti-Mo alloy. In addition, with increasing the sintering temperatures, the microstructure became more homogeneous for β phase, which decreases in the modulus and strength. The Mechanical alloying allows highly homogeneous composition and particle morphology. Bending strength in EB is much higher than MA techniques. Increasing of compaction pressure during MA technique increases the bending strength and decreases the porosity. Moreover, the Ti12Mo6Zr2Fe alloys exhibited higher bending strength/modulus ratios. [ABSTRACT FROM AUTHOR]

Oils and grease have beneficial effects on moving parts such as connecting rod, gears, shafts, and engine to reduce wear and friction. The properties of lubricants such as tribological and rheological properties are an important role in oils and grease characterization. Nano additives on lubricant oils play an important role in anti-wear; reduce the coefficient of friction and enhance the rheological properties. The Tribological and rheological behavior of base oil 15W50 which have different concentrations of multi-wall Carbon Nanotubes (MWCNTs) (0.5, 1, 1.5, and 2 wt%), and constant amount of graphene nanosheets (GNSs) (0.5 wt%) were investigated. This research is the first one in studying the effect of hybrid nano additives of (MWCNTs) and (GNs) on the tribological and rheological properties of lubricant oils. Tribological characterization was carried out on four ball testing model under different loads (200, 400, 600, and 800 N). The kinematic viscosity, flash point, pour point, and thermal conductivity of nanofluid added 15W50 lubricant are estimated and compared with base oil. The results showed that nano additives improve the wear scar and coefficient of friction by 78% and 48%, respectively. The flash point, thermal conductivity, kinematic viscosity, and pour point, were improved by 15%, 77%, 76.8%, and 20%, respectively compared with the base oil. The hybrid addition of CNTs/GNs nanoparticles enhanced the properties of 15W50 engine oil. [ABSTRACT FROM AUTHOR]

• It was found that the microstructure vary with the increase in Mo percentage for both Ti-Mo and Ti-Zr-Mo. • Ti-15Mo-6Zr is a promising alloy as it has a higher percentage of β-phase, low elastic modulus, and highest hardness. • The microstructural analysis showed that the addition of Mo as well as Zr improve the β-phase. This paper investigated the improvement of mechanical properties for one of the most used biomaterials, titanium-based alloy. To improve its mechanical properties, molybdenum was chosen to be added to Ti and Ti-Zr alloys through a mechanical blending process. After homogenization of Ti (12, 15) Mo and Ti (12, 15) Mo-6 Zr, the compaction pressure and sintering temperature were varied to create pellets. Characterization has been done using scanning electron microscopy (SEM), X-ray diffraction (XRD), Vickers's hardness, Archimedes test and ultrasonic method, and 3-point bending test. Micrograph of each pellet revealed the influence of Mo content that plays a prominent role in the variation of microstructure in the alloys Ti-Mo and Ti-Zr-Mo. The porosity and density were also influenced by changing the β-phase. EBSD analysis shows the increase in β-phase with the addition of Zr. The overall results indicated that the percentage of β-phase greatly affects the mechanical properties for the specimens. [ABSTRACT FROM AUTHOR]