Dual Reinforcement Research Articles

Domestic waste (eggshells and banana peels particles) as sustainable and renewable resources for improving resin-based brakepad performance: Bibliometric literature review, techno-economic analysis, dual-sized reinforcing experiments, to comparison ...

The objective of this study is to develop a new environmentally-friendly brake pad made from eggshells (Es) and banana peels (BPs) as reinforcement agents. E and BP particles as dual reinforcement with various compositions were combined. The E/BP mixture was then embedded on a polymer matrix composing a resin/hardener mixture in a 1:1 ratio. As a standard, brake pads using a single reinforcement of E and BP particles were also fabricated. Physical properties (i.e. particle size, surface roughness, morphology, and density), as well as mechanical properties (i.e. hardness, wear rate, and friction coefficient properties) were investigated. It was observed that using dual reinforcements was preferable (compared to using single reinforcements) because they had a synergistic effect on the mechanical properties of the brake pad. The best mechanical properties were found in dual reinforcements of brake pad specimens using E/BP particles with a higher BP ratio in which the value of the stiffness test, puncture test, wear rate, and coefficient of friction were 4.5 MPa, 86.80, 0.093×10-4 g/s.mm2, and 1.67×10-4, respectively. A high BP particle ratio played a dominant role in dual reinforcements, increasing the resin's bonding ability and resulting in good adhesion between the reinforcement and matrix. When compared to commercial brake pads, the brake pad specimens fabricated in this study met the standards. The techno-economic analysis also confirmed the prospective production of brake pads from E and BP particles (compared to commercial brake pads). From this research, it is expected that environmentally friendly and low-cost brake pads can be used to replace the dangerous friction materials.

Experimental investigation on mechanical behavior of as cast Zn-Al-Cu/SiC/TiB2 hybrid metal matrix composite by ultrasonic assisted stir casting technique

Now a days, the Zn-Al-Cu alloy-based composites have great impact on modern trends for bearing applications because of its reliable mechanical performance. In this paper the mechanical characteristics of as cast Zn-Al-Cu alloy-based hybrid metal matrix composites have been investigated, as well as the influence of reinforcements Silicon Carbide (SiC) and Titanium Diboride (TiB2) on the composite. The ultrasonic assisted stir casting technique has been adopted for fabricating the composites with the addition of dual reinforcements like 5 wt% of SiC as constant and by varying the wt% of TiB2 as 0 wt%, 5 wt% and 10 wt%. The ceramic particles SiC and TiB2 are taken with 20 and 30 microns in size. The ASTM standards were used to conduct the different tests, and the findings demonstrate the significance of adding reinforcements to alloy and also noticeable increase in mechanical performance in terms of hardness, tensile strength, young’s modulus and impact strength. As cast Zn-Al-Cu/5 wt.% of SiC/10 wt.% of TiB2 hybrid composite gives the minimum density as 4.79 g cc−1 and maximum hardness as 156Hv.

Evaluation of copper chill on tribological behaviour of LM13/ZrSiO<sub>4</sub>/C hybrid metal matrix composites

Composites place a vital role in applications of material science I,e aerospace, automobile, marine, etc... Dual reinforcement composites are a trending research area in the field of metal matrix composites. In this research article dual reinforcement i.e zirconium silicate and carbon are added to molten LM13 using the stir casting process in terms of (3+3), (6+3), (9+3) and (12+3) wt.% respectively using copper as a chill kept toward one end. Tensile, hardness, and microstructural studies are done on the composite specimen at the chill end and non-chill. It is found an increase in reinforcement and chilling effect increases the properties of the composite.

Achieving synergistic strengthening and enhanced comprehensive properties of Cu matrix composites at high strength level by incorporating nanocarbons and Al2O3 dual reinforcements

Cu metal matrix composites (MMCs) incorporated with dual reinforcements of nanocarbons and Al2O3 particles with different contents were prepared by accumulative roll-compositing (ARC). Microstructure and properties of the dual-reinforced Cu MMCs were systematically investigated and compared with those of the individual-reinforced counterparts. Results showed that both the individual and dual reinforcements can be homogenously incorporated into and well-bonded with Cu matrix by ARC. The dual-reinforced Cu MMCs exhibited high strength (up to ∼747 MPa) and better comprehensive properties of strength/elongation and strength/electrical conductivity than those of the individual counterparts. Moreover, a synergistic strengthening effect of 1 + 1>2 of the dual reinforcements was revealed. The influences of content, distribution and interfacial interaction of the dual reinforcements on the properties of the Cu MMCs were discussed. This study indicated the method and mechanisms for further improving the comprehensive properties of Cu MMCs at high strength level by introducing dual reinforcements.

Effect of graphene nano plateletson microstructural and wearbehavior of AA7075/Al2O3Nano composites

Aluminum hybrid metal matrix composites are a new generation of composites that comprises of aluminum as matrix and dual reinforcements. The primary reinforcement can be ceramic oxides, borides, nitrides, carbides and secondary reinforcement can be carbonaceous nano materials. In the present work hybrid composites are manufactured with AA7075 as matrix and Al2O3 nano particles and GNPs as reinforcements manufactured by powder metallurgyprocess. The microstructural characterization is performed by SEM and XRD analysis. The results indicated uniform distribution of GNPs and nano Al2O3 in the matrix. The wear behavior of the composites was studied for different compositions and wear rate has been evaluated. The microstructural investigation of worn out surfaces indicated abrasive and adhesive wear mechanisms.

Influence of graphene oxide nanosheets and multi-walled carbon nanotubes on the thermoelectric and mechanical properties of Mg2(Si0.3Sn0.7)0.99Sb0.01

Achieving the simultaneous improvement of thermoelectric and mechanical properties is of great significance for the application of thermoelectric materials. Here, we fabricate the bulks of Mg2(Si0.3Sn0.7)0.99Sb0.01 hybrid composites reinforced by graphene oxide nanosheets (GOs) and multi-walled carbon nanotubes (MWCNTs). The influences of GOs and MWCNTs on the thermoelectric and mechanical properties of the composites are characterized in detail. It is found that the hybrid composites exhibit obvious improvements in flexural strength and fracture toughness with respect to both the matrix and the samples reinforced by GOs or MWCNTs alone, owing to the remarkable synergistic effect of GOs and MWCNTs. Meanwhile, the dimensionless figures of merit are basically maintained or even slightly enhanced when dual reinforcements of GOs and MWCNTs are introduced. Our work provides a feasible path to obtain excellent mechanical and thermoelectric properties simultaneously.

Thermotropic liquid crystalline polymer reinforced polypropylene composites enhanced with carbon nanotubes for use in fused filament fabrication

AbstractThe objective of this research was to enhance the mechanical properties of wholly thermoplastic composites (WTCs) used in fused filament fabrication (FFF). Multiscale thermoplastic composites, which were based on the use of polypropylene (PP) reinforced with thermotropic liquid crystalline polymer (TLCP) and carbon nanotubes (CNTs), were prepared by a method combining supercritical carbon dioxide (scCO2)‐aided exfoliation and dual‐extrusion technologies. Significant enhancement of tensile properties was observed by using 1 wt% exfoliated CNTs to reinforce WTCs consisting of PP with and without maleic anhydride‐grafted polypropylene (MAPP, 16 wt%). With 1 wt% CNTs and 16 wt% MAPP dual reinforcement, 20 wt% TLCP reinforced WTCs based on PP exhibited 265%, 274%, and 182% improvement in the tensile modulus of the filaments, laid up specimens in the concentric pattern, and laid up specimens in ±45° rectilinear pattern, respectively. For tensile strength, 1 wt% CNTs reinforcement combined with 16 wt% MAPP improved the 20 wt% TLCP reinforced WTC filaments, laid down parts in the concentric pattern, and ±45° rectilinear patterns by 73%, 53%, and 65%, respectively. The tensile modulus and strength of multiscale WTC based on MAPP/PP specimens laid down with a concentric pattern are higher than those reported for PP/40 wt% short carbon fiber and PP/48.5 wt% short glass fiber laid down specimens. The advanced tensile modulus properties of 1 wt% CNTs reinforced WTCs are competitive with 9 wt% continuous carbon fiber reinforced nylon composite materials in FFF. Scanning electron microscopy analysis showed extremely strong interfacial adhesion between the TLCP fibrils and the matrix in multiscale WTC filaments and laid down parts, compared to the WTCs with no CNTs reinforcement. The advanced interfacial adhesion between TLCP fibrils and matrix resulted in an enhancement in the tensile strength. The exfoliated CNTs were premixed with the matrix, but they were trapped at and aligned with TLCP fibrils, which may be the primary reason for tensile modulus enhancement.

Assessment of erosion rate on AA7075 based surface hybrid composites fabricated through friction stir processing by taguchi optimization approach

In recent years, Aluminium Alloy 7075 plays a vital role in the manufacturing of aircraft wing and fuselage skin due to its light weight and specific strength characteristic behavior. The components like aircraft wing and fuselage skin faces serious erosion issues due to sand particles while high speed running conditions. This issue is focused into the present research and fabrication of AA7075 Surface Hybrid Composites (SHCs) with reinforcements like Aluminium Oxide (Al2O3) and silicon carbide (SiC) through the novel Friction stir Processing (FSP) technique is suggested. Microhardness tests are performed for different combinations of dual reinforcement and the erosion resistance is evaluated for the specimen with superior microhardness value. This research aims particularly on evaluating the erosion performance of the aforementioned hard specimen. Input erosion parameters like jet distance, jet pressure, jet angle, erodent impinging time and mesh number of erodent are considered and they are optimized through Taguchi technique. The obtained result undergoes Analysis of Variance (ANOVA) test and each parameter based percentage contribution is identified. The surface morphology analysis shows that grain refinement and homogenous distribution of reinforcement particles are at less surface degradation when compared to base AA7075.

Influence of Dual reinforcement on Mechanical Characteristics of Hot Rolled AA7075/Si3N4/Graphite MMCs

Influence of Dual reinforcement on Mechanical Characteristics of Hot Rolled AA7075/Si3N4/Graphite MMCs

Cooperative Channel Assignment for VANETs Based on Dual Reinforcement Learning

Dynamic channel assignment (DCA) is significant for extending vehicular ad hoc network (VANET) capacity and mitigating congestion. However, the un-known global state information and the lack of centralized control make channel assignment performances a challenging task in a distributed vehicular direct communication scenario. In our preliminary field test for communication under V2X scenario, we find that the existing DCA technology cannot fully meet the communication performance requirements of VANET. In order to improve the communication performance, we firstly demonstrate the feasibility and potential of reinforcement learning (RL) method in joint channel selection decision and access fallback adaptation design in this paper. Besides, a dual reinforcement learning (DRL)-based cooperative DCA (DRL-CDCA) mechanism is proposed. Specifically, DRL-CDCA jointly optimizes the decision-making behaviors of both the channel selection and back-off adaptation based on a multi-agent dual reinforcement learning framework. Besides, nodes locally share and incorporate their individual rewards after each communication to achieve regional consistency optimization. Simulation results show that the proposed DRL-CDCA can better reduce the one-hop packet delay, improve the packet delivery ratio on average when compared with two other existing mechanisms.

Synergistic effect of crosslinking and dual reinforcement on the thermal and mechanical properties of polyvinyl alcohol

AbstractWe examined the combined effect of crosslinking and dual reinforcement on the thermal and mechanical properties of polyvinyl alcohol (PVA). Glutaric acid (GA) was used as crosslinker while tungsten disulfide nanotubes (WSNT) and carboxylated multiwall carbon nanotubes (f‐MWCNT) were used as dual reinforcing agents. Tensile strength and toughness of the hybrid composite, that is, crosslinked PVA reinforced with both f‐MWCNT and WSNT, was higher than those of neat PVA, crosslinked PVA, crosslinked PVA reinforced with WSNT and crosslinked PVA reinforced with f‐MWCNT. The hybrid composite showed remarkable improvement over neat PVA: tensile strength increased by 138%, Young's modulus increased by 142%, and toughness increased by 246%. Water uptake tendency and thermal stability of the composites were also examined and compared. The advantage of using dual reinforcement was a simultaneous increment in tensile strength and toughness, similar to what is observed in some natural materials like nacre.

In-situ chemical reaction mechanism and non-equilibrium microstructural evolution of (TiB2 + TiC)/AlSi10Mg composites prepared by SLM-CS processing

The preparation of aluminum matrix composites (AMCs) by laser additive manufacturing (AM) technology has become an important means of improving performance of aluminum alloys. In this work, a novel in-situ synthesis method of selective laser melting combined combustion synthesis (SLM-CS) was used to prepare dual-phase reinforced AMCs. The feasibility of a B4C–Ti combustion synthesis reaction system to produce TiB2 and TiC ceramics by selective laser melting (SLM) was verified. AlSi10Mg alloy matrix composites with dual reinforcements were then fabricated by SLM, and systematic qualitative and quantitative phase analysis was carried out. The calculation results of the graphical-extrapolation method show that the lattice constant of α-Al matrix phase in the composites increases from 0.40466 nm to 0.40528 nm. The effects of a series of reactants with different chemical element composition ratios on the characteristics of melting process and non-equilibrium solidification microstructure were studied. The preliminary principles of the combustion chemical reaction under the rapid and continuous laser scanning were concluded from the theory and experiments results. In terms of mechanical properties, an appropriate amount of ceramic particles results in a significant improvement in the microhardness and elastic modulus, and yet composites prepared with a mixture powder amount greater than 0.7 wt % witnessing a clear drop in the tensile strength as well.

Experimental Investigation on Microstructural and Wear Behaviour of Dual Reinforced Particles (DRP) Aluminium Alloy Composites

In the present scenario, the automobile industry, and aerospace industries are considerable scuffles to strive for innovative lightweight materials among manufacturing industries. They preserve their place by reducing the cost of their products and services. For this tenacity, the demand for lightweight material, low cost, and high-performance material are needed. Aluminum matrix composite is developed to fulfill and becomes an engineer’s material. Aerospace & Automobile industries are eager to introducing compound aluminum metal matrix composites due to their excellent mechanical & tribological properties which makes a reduction in the weight of the component. In this project the LM13 as the matrix material while SiC and B4C have been considered as dual reinforcement. Stir casting is the modest and inexpensive method of fabricating an aluminum matrix composite. For the Evaluation of Mechanical &Tribological behavior of DRP composite castings (LM13/B4C/SiC) selection for experimentation tests. In this paper different specimens of the MMC with LM13 Al Alloy 2wt% SiC and 2wt% B4C, 2wt% SiC and 4% B4C, 4wt% SiC, 2wt% B4C, 4wt% SiC and 4wt% B4C are taken for carried to invention out the increase in DRP in the composites will intensification the mechanical properties of the LM13 Al Alloy SiC and B4 C composite formed.

Effects of hybrid processing on microstructural and mechanical properties of thixoformed aluminum matrix composite

Abstract Hybrid processing is a promising technique that combines powder metallurgy and liquid casting to disperse reinforced particles in Al–5Si alloy matrix homogeneously. In this study, dual alumina-multiwalled carbon nanotubes (MWCNTs) and single MWCNT-reinforced particles were ball-milled and compacted into pellets. The pellets were then injected into molten Al–5Si at 650 °C, mechanically stirred for 10 min and poured into a mould via a cooling slope for semi-solid feedstock. All samples were subjected to thixoforming and standard T6 heat treatment. The effects of hybrid techniques on the distribution of reinforcements, microstructure and mechanical properties were investigated. Tensile fracture surface analyses showed that dual and single reinforcements were distributed homogeneously in the samples. However, severely damaged MWCNT structures were observed under dual reinforcement due to excessive shear stress during ball milling process. The highest yield strength, ultimate tensile strength and elongation to fracture were 262 MPa, 289 MPa and 7.2% and 316 MPa, 347 MPa and 13.3% for thixoformed-T6 alloy composites of dual and single reinforcements, respectively. The two strengthening mechanisms involved are as follows: by the matrix, microstructure evolution and precipitation; and by reinforcement, load transfer, thermal mismatch dislocation and Orowan looping. The more intact and the longer structure of MWCNTs in PB lead to better effective load transfer ability than the PA composite.

Influence of dual reinforcement (nano CuO + reused spent alumina catalyst) on microstructure and mechanical properties of aluminium metal matrix composite

In the quest of novel, reasonable and effective reinforcement, it is very hard to find rare combination of materials which attempts to accord and benefit each other. The exhausted waste spent catalyst from petroleum industries is experimented as a reinforcement obliging to the concept of reuse and recycle. In this investigation, aluminium metal matrix nano composite is to be synthesized by double stir casting method. Pure aluminium and Spent Alumina Catalyst (SAC) is chosen as matrix and primary reinforcement respectively. Nano CuO is added as secondary reinforcement to enhance the mechanical properties of aluminium spent alumina catalyst composite. The composites are synthesized as such, 10% SAC is reinforced to pure aluminium and the amount of nano CuO is varied 0.5%, 0.75%, 1%. Microstructural characteristics of cast composites and tensile samples is studied under Scanning Electron Microscope. There is no clogging of reinforcement materials (nano CuO and SAC) in the aluminium matrix. The mechanical properties of the composites are determined and compared with pure aluminium. There is an impact of dual reinforcement on aluminium matrix which is evident by the improvement in the mechanical properties of the composite. The optimum composition is Al + 10%SAC +1%nano CuO, which resulted in maximum increase in hardness (77%) and tensile strength (78%).

Enhancement of mechanical properties of aluminium metal matrix composite by reinforcing waste alumina catalyst and nano Al2O3

The manufacturing industries are ready to experiment with the metal matrix composites by miscellaneous materials out of ordinary combination. From the rundown, it is obvious that research is concentrated in recycling or reusing any waste material so as to reduce the usage of conventional materials. The present investigation aims to reuse waste spent catalysts from the petroleum industries (goes as waste in landfills) to synthesize aluminium metal matrix composite. The waste catalysts used in the investigation consists of beneficial elements like alumina, molybdenum, silica, nickel etc. The waste spent catalyst previously proved to increase the strength of cement, bricks etc. in construction field. The inclusion of nano materials enhances the mechanical properties of the metal matrix composites. In this research, aluminium metal matrix composite was synthesized with dual reinforcement of waste alumina catalyst and nano Al 2 O 3 by Stir casting. The ratio of nano Al 2 O 3 was varied such as 0.5%, 0.75% and 1% along with 10% waste alumina catalyst in the aluminium matrix. The nano composites were tested for hardness and tensile strength with a detailed microstructural study using Scanning Electron Microscope. The nano composites resulted with improved mechanical properties than pure aluminium. The nano composite Al + 10%WAC + 1% nano Al 2 O 3 , yielded the highest hardness of 94HRB and tensile strength of 115.21 MPa.

Nanochitin/metal ion dual reinforcement in synthetic polyacrylamide network-based nanocomposite hydrogels

Nanocomposite hydrogels consisting of a synthetic matrix reinforced by nanosized crystalline polysaccharides offer significant potential in various fields. Different from nanocellulose, the combination of nanochitin with synthetic polymers to obtain nanocomposite hydrogels has not been extensively and systematically studied. Herein, a physically and chemically dual crosslinked nanocomposite hydrogel was successfully synthesized, where chitin nanowhiskers (ChNWs) and Zn2+ were incorporated within polyacrylamide (PAAm) matrix. Nanochitin/metal ion dual reinforcement imparts increased elasticity, enhanced mechanical properties, and improved recovery performance to PAAm network. The PAAm/ChNWs/Zn2+ hydrogel could be stretched to over 13 times its original length with tensile strength of 321.9 ± 8.2 kPa, and restore its original shape rapidly even when compressed at a strain of 95% with a corresponding compressive strength of 6.95 ± 0.20 MPa. The multiple crosslinks and interactions among ChNWs, Zn2+ and synthetic polymeric network were investigated. Moreover, the hydrogel was applied in drug release and soft bioelectronics.

MICROSTRUCTURAL ANALYSIS, MICROHARDNESS AND COMPRESSIVE BEHAVIOUR OF DUAL REINFORCED PARTICLES ADC-12 ALLOY COMPOSITE

The aim of this study was to determine the compressive properties of silicon carbide (SiC) and zircon sand (ZrSiO4) particulate reinforced with ADC-12 alloy, ADC-12 alloy composite. In this experimental study, SiC and ZrSiO4 particulates reinforced with ADC-12 alloy composite were manufactured by stir casting methods. Compressive properties of these composite materials were investigated by different weight percentages of dual reinforcement combinations (9+3) %, (6+6) %, (3+9) %wt. silicon carbide (SiC) and zircon sand (ZrSiO4)respectively, The compressive tests were conducted to determine compressive strength and young’s modulus to investigate the effects of reinforce materials on different combinations of weight percentages. The outcome of the investigations reveals that the tensile strength of composites reinforced by Zircon sand (ZrSiO4) and silicon carbide particles with a total reinforcement 12% wt, and in this hybrid reinforcement the variations (9+3) %, (6+6) %, (3+9) % were taken in to account for investigating the properties such as density, compressivestrength and hardness of the composites synthesized by Stir casting technique, also compared between each other’s. The mechanical properties evaluation reveals variations in hardness and the compressive strength values with the composite combinations. From the experimental studies, the optimum volume fraction of hybrid reinforcement in ADC-12 alloy on the basis of microstructure and mechanical properties it is found that the (6+6) wt.% combination.

Online Radio Pattern Optimization Based on Dual Reinforcement-Learning Approach for 5G URLLC Networks

The fifth generation (5G) radio access technology is designed to support highly delay-sensitive applications, i.e., ultra-reliable and low-latency communications (URLLC). For dynamic time division duplex (TDD) systems, the real-time optimization of the radio pattern selection becomes of a vital significance in achieving decent URLLC outage latency. In this study, a dual reinforcement machine learning (RML) approach is developed for online pattern optimization in 5G new radio TDD deployments. The proposed solution seeks to minimizing the maximum URLLC tail latency, i.e., min-max problem, by introducing nested RML instances. The directional and real-time traffic statistics are monitored and given to the primary RML layer to estimate the sufficient number of downlink (DL) and uplink (UL) symbols across the upcoming radio pattern. The secondary RML sub-networks determine the DL and UL symbol structure which best minimizes the URLLC outage latency. The proposed solution is evaluated by extensive and highly-detailed system level simulations, where our results demonstrate a considerable URLLC outage latency improvement with the proposed scheme, compared to the state-of-the-art dynamic-TDD proposals.

Experimental Studies on Wear Resistance & Mechanical Properties of Aluminium Hybrid Composites (LM25/Al<sub>2</sub>O<sub>3</sub>/Graphite)

This paper involves the fabrication of hybrid Aluminium matrix composite samples of different compositions using Stir casting technique and testing the prepared hybrid composite test specimens for analysing their wear and mechanical properties. LM25 Al alloy was used as matrix material reinforced with constant 9 wt.% of Al₂O₃ with particle size of 6-23 μm and different wt. percentages of Graphite (particle size of 24-94 μm) as 3%, 4% and 5% to prepare hybrid composite samples of three different compositions. Mechanical properties, for examples, tensile strength, hardness, compression strength and impact strength were analysed for both base LM25 Al. alloy and composite samples. Wear loss and coefficient of friction of composite samples also were studied using Pin-on-disc apparatus. Microstructure images of the hybrid composite samples were examined to study dispersion of dual reinforcement particles in the matrix material, porosity and shrinkage cavities developed during the casting of the composite samples using Optical Microscope. Results revealed that Tensile strength, Hardness and Wear properties of the hybrid composite sample, having 9 wt.% of Al₂O₃ and 4 wt.% of Graphite particles, were found to be superior to those of re-cast LM25 Al. alloy. This study is mainly focussed on achieving the improved wear resistance and mechanical properties of the hybrid aluminium matrix composite materials for meeting the desired properties of the products by exploring newer compositions of the dual particles reinforced hybrid composites.