Evaluation of Mechanical and Wear Properties of Ceramic and Inorganic compounds based Composite via PM route and Optimization through Robust design technique

The present research study investigates the Mechanical, Physical, and Tribological properties of powder metallurgy (PM) produced AA6063 alloy reinforced with silicon nitride (Si3N4) and copper nitrate (CuN2O6). Incorporation of Si3N4 & CuN2O6 reinforcement in matrix material ranged from 6 to 12 % Si3N4 in a 6-step interval and 2 to 6 %CuN2O6 in a two-step interval. The characterizations were made on the PM-produced specimens using OM, EDS, XRD, and Hardness. The reinforcement particles were uniformly distributed, which was attributed to a homogeneous mixer of matrix and reinforcements. The test findings show that as the reinforcing percentage of the ceramic and inorganic compound increases, properties such as hardness and density rise considerably and monolithically. The existence of phases such as Si3N4 and CuN2O6 reinforcement in the AA6063 matrix was ensured by X-ray diffraction. The hardness of AA6063/12%Si3N4/6%CuN2O6 increased by 88% over the base alloy due to a mismatch in thermal expansion between the Al matrix and reinforcement, which causes massive internal stress, causing the aluminium matrix to plastically deform to accommodate the reduced volume expansion of Si3N4 and CuN2O6 particles. The dry sliding wear test was determined using the Pin-on-Disc method, and the results show that the composite is more wear-resistant. An orthogonal array and analysis of variance were utilized to evaluate the solution, including parameters using the Taguchi robust design technique. The weight percentage of the Si3N4/CuN2O6 compound and the relationship between weight % of reinforcement and applied load had the most significant impact on composite wear resistance. The produced composite's wear morphology was studied using images from a scanning electron microscope and energy dispersive spectroscopy.

Breakdown Performance and Partial Discharge Development in Transformer Oil-Based Metal Carbide Nanofluids

In this work, the influence of semi-conductive SiC nanoparticles on the AC breakdown voltage and partial discharge development in natural ester oil FR3 is examined. Primarily, the dielectric constant and the electrical conductivity of the nanoparticles are measured following the broadband dielectric spectroscopy technique. The nanoparticles are added into the matrix following the ultrasonication process in three weight percentage ratios in order for their effect to be evaluated as a function of their concentration inside the base oil. The processing of the results reveals that the nanofluid containing SiC nanoparticles at 0.004% w/w demonstrates the highest AC dielectric strength improvement and shows the greatest resistance to the appearance of partial discharge activity. The mechanisms behind the aforementioned results are discussed in detail and confirmed by the broadband dielectric spectroscopy technique, which reveals that this particular nanofluid sample is characterized by lower dielectric constant and electrical conductivity than the one with double the weight percentage ratio.

Small Angle Neutron Scattering Reveals Wood Nanostructural Features in Decay Resistant Chemically Modified Wood

While it is known that modifying the hydroxyls in wood can improve the decay resistance; what is often missing in the literature is whether these modifications alter wood nanostructure, and how these changes correlate to the improved decay resistance. Here, we used small angle neutron scattering (SANS) to probe the effects of alkylene oxide modifications on wood nanostructure. Southern pine wood samples were chemically modified to various weight percentage gains (WPG) using four different alkylene oxides: propylene oxide (PO), butylene oxide (BO), epichlorohydrin (EpH), and epoxybutene (EpB). After modification, the samples were water leached for 2 weeks to remove any unreacted reagents or homopolymers and then equilibrium moisture content (EMC) was determined at 90% relative humidity (RH) and 27°C. Laboratory soil block decay evaluations against the brown rot fungus Gloeophyllum trabeum were performed to determine weight loss and biological efficacy of the modifications. To assist in understanding the mechanism, SANS was used to study samples that were fully immersed in deuterium oxide (D2O). These measurements revealed that the modifications altered the water distribution inside the cell wall, and the most effective modifications reduced the microfibril swelling and preserved the microfibril structure even after being subject to 12 weeks of brown rot exposure.

Flexural Behaviour of Reinforced Geopolymer Concrete Incorporated with Hazardous Heavy Metal Waste Ash and Glass Powder

The flexural behavior of Incinerated Bio-Medical Waste Ash (IBWA) – Ground Granulated Blast Furnace Slag (GGBS) based Reinforced Geopolymer Concrete (RGPC) beams with Waste Glass Powder (WGP) as fine aggregate is explored in this research. The fine aggregate (M-Sand) is substituted by varying the waste glass powder as 0 percent, 5 percent, 10 percent, 15 percent, 20 percent, 25 percent, 30 percent, 35 percent, 40 percent, 45 percent, and 50 percent, and the mixture is cured under atmospheric curing. The impact of the WGP weight percentage on the flexural behavior of GPC beams is analyzed. The conduct of RGPC beams varies from that of ordinary Portland Concrete (OPC) beams, which is defined and examined. Deflection, ductility factor, flexural strength, and toughness index were measured as flexural properties for beams. In contrast to the reference beams, the RGPC beams containing 50% Waste Glass Powder as fine aggregate demonstrated a major increase in cracking resistance, serviceability, and ductility, according to the experimental finding. The RGPC beam without WGP ended in failure with a brittle manner whereas those beams with WGP encountered ductile failure. The RGPC beams' load ability improved by up to 50% as the weight percentage of WGP was enhanced.

Mechanical Properties of Reinforced Polymer Concrete with Three Types of Resin Systems

This paper studies the mechanical properties of polymer concrete (PC) with three types of resin systems. First, the effect of 0.5 wt% up to 3 wt% basalt fiber on the mechanical properties of a quaternary epoxy-based PC is investigated experimentally, and the best weight percentage of basalt fiber is obtained. The results show that adding basalt fiber to PC caused the greatest enhancement within 10% in compressive strength, 10% in flexural strength, 35% in the splitting tensile strength, and 315% in impact strength. In the next step, the effect of nanoclay particles on the mechanical properties of basalt fiber-reinforced PC (BFRPC) is analyzed experimentally. Nanoclays increase the compressive strength up to 7%, flexural strength up to 27%, and impact strength up to 260% but decrease the tensile strength of the PC. Field-emission scanning electron microscopy (FESEM) analysis is performed to study the fracture surface and morphology of various concrete specimens. In the last step, we consider the effect of two other different resin systems, rigid polyurethane and rigid polyurethane foam on the mechanical properties of reinforced polymer concrete. A comparison study presents that the epoxy PC has a higher specific strength than the polyurethane and ultra-lightweight polyurethane foam PC.

Feasibility study: Resin-based functionally graded material incorporated with carbonized waste rice husk

Feasibility study was conducted in exploring the fabrication and characterization of resin-based functionally graded material (FGM) incorporated with carbonized waste rice husk. The waste rice husks were converted into carbon materials through heat treatment under the presence of inert gas at 500°C for 2 hours. Then, they were incorporated into resin to form FGM by centrifugal method to achieve desired gradation. Sample B3 with 5 wt.% of carbonized rice husk (CRH) incorporated into polyester resin (including hardener and ethanol) was centrifugated at 4000 rpm for 30 minutes to form FGM. The fabricated samples were cut into three parts, namely upper, middle, and bottom layer to further characterize the properties at various gradation levels. The density of sample B3 increased gradually, 4.10%, 6.54%, and 6.93% when compared to bulk resin, from upper to bottom layer, respectively. The hardness of sample B3 increased gradually, 27.38%, 42.57%, and 47.08% in contrast to bulk resin, from upper to bottom layer, respectively. FGM proposed in this study can be further manipulated based on the centrifugal force and time, ratio of solvents/hardener, and weight percentage of CRH that indicate they can be exploited for specific of numerous appropriate applications.

The curious saga of dehydrogenation/hydrogenation for chemical hydrogen storage: A mechanistic Perspective

Hydrogen Storage is an indispensable component of hydrogen based fuel economy. Chemical hydrogen storage relies on development of lightweight compounds which can deliver high weight percentage of H2 at moderate...

Fabrication and tribological behavior of novel UHMWPE/vitamin-C/graphene nanoplatelets based hybrid composite for joint replacement

Purpose This study aims to fabricate and investigate the tribological performance of ultra-high molecular weight polyethylene (UHMWPE)-based composite materials reinforced with 0.5, 1 and 2 weight percentage of graphene nanoplatelets (GNPs) while keeping the weight percentage of vitamin C constant at 2% for each composite. Design/methodology/approach In this paper, the composites were fabricated using hot pressing, and the dispersion of GNP/vitamin C/UHMWPE hybrid composite was investigated by X-ray diffraction. Experimental trials were performed according to ASTM F732 on a reciprocating sliding tribometer (pin-on-disc) at human body temperature of 37 ± 1 °C, for a load of 52 N, to assess the role of these fillers on the tribological properties of UHMWPE against Ti6Al4V counter body material under dry and lubricating (human serum) environment. Findings In this study, it has been observed that friction and wear behavior of the developed composites improve with increase in weight percentage of GNP, and human serum adheres to the surface of the composite pins upon sliding, resulting in the formation of a film, which results in better wear resistance of the composite pins under human serum lubrication than dry sliding. Scanning electron microscope was used to investigate the worn surface morphological examination of the composite materials. Specific wear rate of 0.76 × 10−7 mm3/Nm was attained for 2 Wt.% GNP-filled composite under human serum lubrication. Practical implications The results indicate the compatibility of the composite material used in this study and suggested the in vitro implant application. Originality/value The presented work includes novel study of synergistic effect of GNP (which acts as a solid lubricant) and vitamin C (added as an antioxidant) on the tribological performance of UHMWPE under dry and human serum lubrication.

Assessment of New Composites Containing Polyamide-6 and Lead Monoxide as Shields against Ionizing Photonic Radiation based on Computational and Experimental Methods

This study aimed to introduce new composites, containing polyamide-6 (PA6) and lead monoxide (PbO), to protect against ionizing photon sources used for diagnostic and therapeutic purposes. Five composites, containing various weight percentages of PbO filler (0, 5, 10, 20, and 50%), were developed in this study. Initially, the numerical attenuation value was estimated using XMuDat program by calculating the mass attenuation coefficients at different energy levels. Next, the samples were synthesized based on the melt-mixing method in a laboratory mixing extruder, and their characteristics were determined by scanning electron microscopy (SEM), energy dispersive X-ray (EDX) analysis, X-ray diffraction (XRD), and thermogravimetric analysis (TGA). Finally, experimental radiation attenuation tests were carried out. Based on the SEM results, the acceptable filler weight percentage was up to 20%; however, substantial aggregates formation was observed at the highest weight percentage. The results of XRD analysis showed a higher tendency for crystallization by decreasing the amorphous area, while increasing the filler weight percentage. Moreover, the amount of mass loss was monitored at different temperatures, revealing that the filler incorporation improved the thermal durability of the samples. According to the radiation results, a good agreement was observed between the experimental and computational data, except when aggregates formation was substantial. According to the experimental data, by increasing the lead weight percentage from 0% (crude PA6) to 50%, the half-value layer decreased from 3.13 to 0.17 cm at an energy level of 59 keV and from 7.28 to 4.97 cm at an energy level of 662 keV. Considering these promising results, the applicability of PA6/PbO composites for protection against low- and medium-energy ionizing photon sources must be investigated in future studies.

The Effect of Wear Rate on Polymeric Composites Reinforced Nanoclays

This research aims to study the addition of nanoclays on unsaturated polyester (UP) and epoxy resin (EP) as filling and by weight percentage (2%, 4% and 6%) to this mixture and then study the extent of the effect of this addition on wear rate of the composites’ material where three loads were adopted (10, 15 and 20[Formula: see text]N), respectively, on the iron hard disk (269 HB) and copper hard disk of 111[Formula: see text]HB for the resin before and after adding the clays, where the approved sliding velocities were 4.1887, 3.1415 and 2.0943[Formula: see text]m/sec, respectively, and the test duration was 10 min on the test disc. Immersion of samples in the water for 2, 4, 6 and 8 weeks showed a clear improvement in the wear rate and tear values of dry and submerged conditions in a water under different conditions of load change, slipping speed, time and temperature stability after adding the nanoclays to the polymer.