This study presents the development and comprehensive microstructural and mechanical characterization of a phenolic resin-based composite strengthened with lignocellulosic sisal fiber (SF), basalt fiber (BF), bio-waste cattle horn powder, graphene oxide (GO), graphite, alumina, SiC, and barite, where inclusion of hybrid natural reinforcements (SF and BF) is making this work unique. Multiple composites are fabricated using a temperature and pressure controlled hot press compression molding process with varying compositions of the composite ingredients mainly SF (2.5-10 wt%), BF (2.5-10 wt%), and GO (0.1-0.5 wt%) to capture their different combinations effect on final composite properties. The best composite (PC-T3) came up with the inclusion of 10%/10%/0.5% weight of SF/BF/GO. The flexural strength and compressive strength improvements in PC-T3 are recorded about 167% and 161% respectively as compared to neat phenolic resin (P0). PC-T3 thermal stability index also enhanced by approximately 118% as compared to P0. Dynamic mechanical analysis result confirmed a remarkable enhancement in the stiffness property of PC-T3, where its storage modulus improved by 803% approximately as compared to P0 at 300 °C, which highlights its thermo-mechanical behavior superiority. From tribological study, the composites average coefficient of friction found in the range of 0.32 to 0.45, and specific wear rate in between 3.89 × 10- 5 to 9.27 × 10- 5 mm3/N-m, where PC-T3 came up with very less specific wear rate. Further Taguchi analysis revealed that the composition is the most significant influencing factor, followed by load and sliding speed for developed composites tribological properties. Even fracture and worn surface of the composites are investigated using SEM and found improved stress transfer, a transition from matrix-dominated failure to fiber breakage and pullout, and resistance to crack propagation mechanisms in hybrid composites. The developed composite overall results confirm its potential as a sustainable alternative material for lightweight automotive friction-based applications.

In this study, the closed-cell aluminum foam was successfully fabricated using the AA6061 alloy via friction stir processing with titanium hydride as a blowing agent and alumina (Al2O3) as a stabilizing agent. The influence of Al₂O₃ addition, ranging from 4 to 10 wt

Present work aims to analyze the effect of including carbon-based nano materials in the thermosetting polymer based composite in terms of their tribological properties based on critical assessment of several literature data in this field of research.In particular, nanocarbon materials such as carbon nano tubes (CNT), graphene oxides (GO), and graphene are effectively being incorporated in to various polymers as a reinforcement agent to develop polymer nanocomposite based brake pad material.Phenolic and epoxy resins are found to be the most popular thermosetting polymers in practice and research for brake pad material development.Accordingly, the role of nanocarbon which is responsible for the stable coefficient of friction and reduced wear rate due to its inclusion in to phenolic and epoxy resins-based polymer composite have been studied in the present work.As per the present meta-analysis of tribological properties for nanocarbon based phenolic and epoxy resins polymer composite, the analyses showed that an average of around 65% specific wear rate reduction using 5 wt% graphene inclusions in the phenolic based polymer composite as compared to the 5 wt% graphitebased phenolic polymer composite.While in other case a wear rate reduction of 70%, 85%, and 94% were also achieved using 1.5 wt% CNT, 5.3 wt% graphene, and amino treated 0.2 wt% GO respectively in epoxy resin-based polymer composite as compared to pure epoxy resin in all the cases.Moreover, nanocarbon potential in reduction of wear rate for both phenolic and epoxy resin based nanocomposites are found practically evident while maintaining the stable coefficient of friction.Finally the nanocarbon found to be highly potential in affecting the tribological properties with limited amount addition in both phenolic and epoxy polymer composites, while at the same time it is also found that the nanocarbon effect may not pop up in same way when many ingredients added in the phenolic and epoxy polymer composites.

Aluminium foams are an emerging multifunctional material with a distinct structure and unique properties. However, controlling the porosity and pore morphology is still challenging because of the dependency on a number of the process parameters. This study uses a statistical approach to control porosity and influence of each parameter on porosity in a friction-stir processed aluminium plate. A second-order Response Surface Methodology (RSM) model is developed, and relationship among porosity and process parameters like Weight % TiH2, Weight % Al2O3, number of passes, tool rpm, and foaming temperature has been established and influence of each parameter on porosity is investigated. Experimental results validate the model, optimising 80-85% porosity for multifunctional applications. The optimal parameters are 1.2 wt% TiH2, 2.3 wt% Al2O3, 3 passes, 3000 tool rpm, and 738 degrees C foaming temperature. It was observed from the ANOVA that most influencing parameter is tool rpm, number of passes, followed by foaming temperature. The Scanning electron microscopy (SEM) and Energy-dispersive X-ray spectroscopy (EDS) analyses of the fabricated foam at its optimised condition confirm the uniform distribution of pores and the elements. This statistical optimisation model minimises experimental time and resource usage, demonstrating substantial technical and industrial significance.

Nowadays conducting polymer based nanocomposites become promising materials for various field of applications like energy harvesting, electronics, and gas sensing devices. This work focuses on the meta -analysis of the effect of different inorganic micro/nano-material additives on polyaniline (PAni) based nanocomposite for ammonia (NH 3 ) gas sensor application at room temperature. The considered NH 3 sensors performance parameters are sensitivity, limit of detection (LOD), response time, and recovery time. These parameters show a significant change when inorganic materials like graphene, metal oxides and ternary hybrid materials are mixed with PAni as compared to pure PAni due to the synergetic effect of the micro/nano hybrid combination. The changes in the sensitivity, LOD, response time, and recovery time are elaborated by considering different inorganic micro/nano-material additives in PAni in the framework of pure PAni as a reference point. It is found from analysis that a micro/nano additive in the PAni matrix serve as catalyst and create more active sites in the system, which improves the sensitivity in the range of 23-130 times and LOD is highly reduced by 10 -1 to 10 -3 order when compared with the sensitivity and LOD of pure PAni. Hence these additives in PAni-based nanocomposite are very crucial and make nanocomposite cost-effective compared to conventional NH 3 gas sensors while working at room temperature.

Microstructural evolution and resulting stress, strain, and concentration field distribution during Al3X (X = Sc, Zr, Er) precipitation in Al matrix are investigated in this work using the 3D-multiphase field method. Depending on the heat treatment, modulus mismatch, lattice parameter mismatch, and interfacial free energy, precipitate developed to rhombicuboctahedron, and near cuboidal morphologies. The composition distribution and Al-Al3X transformation driving force map identified a difference in precipitation kinetics for each alloy. The precipitation mechanism in the three systems is analyzed in detail with temporal evolution plots of energy components during phase transformation. Al3Er precipitate exhibits the highest growth rate due to Er's high diffusivity and significant lattice parameter mismatch in the Al-Er system. The system has a high chemical and elastic driving force for particle growth, thus attaining quasi-static equilibrium at a relatively lower temperature and time. Therefore, this system observes high magnitude stress, strain, and strain energy field around the Al matrix. The theoretical simulation results obtained from the present study will benefit aluminum multicomponent alloy design for high-strength applications.

Aluminum foams with varying densities of 1.21-0.62 g/cm3 and pore sizes of 0.3-5.8 mm were successfully fabricated by friction stir processing (FSP) by varying the foaming temperature and fixing FSP parameters. Further, the combined effect of density and pore distribution on quasi-static compression deformation was investigated with a fixed strain rate of 0.001 s−1. Experiments have been done to establish a relationship between the stress–strain curve and the cell deformation mechanism. A separate compressive stress–strain curve is drawn to a minimum density of 0.62 g/cm3, while corresponding deformation points on the curve are analyzed by the SEM micrograph and related to identifying the cell failure mechanism. The EDS mapping was also done to illustrate the elemental Ti, O and Al distributions before and after compression. The compression testing identified four types of cell failure, including hinge formation, shearing, bending and crack initiation with tearing. Furthermore, the combined effect of density and pore size on different mechanical properties has been studied. Quasi-static compression studies confirm that with an increase in density and pore size, plateau stress and energy absorption also increased in the studied region. Energy absorption per unit volume was reported highest at a density of 1.21 g/cm3.

This study delves into the evolution of a large number of L12 coherent precipitates within a supersaturated Al-X (X = Sc, Zr, Er) alloy through extensive phase-field simulations. The investigation incorporates a chemomechanical cross-coupling mechanism, accounting for the interplay between mechanical relaxation and diffusion. This coupling is addressed by considering the influence of solute atom concentration on the elastic constants of the matrix phase. The dependencies of elastic constants on solute concentration are determined through density functional theory calculations. The analysis reveals differences in precipitation kinetics among the alloys, characterized by temporal evolution plots of energy components during phase transformation. Al3Er precipitates exhibit the highest growth rate, attributed to Er's high diffusive and mechanical flux in the Al–Er system. The precipitate morphology was defined by isotropic interfacial and elastic-free energy. The results provide valuable insights for the design of high-strength aluminum multicomponent alloys, particularly in applications demanding enhanced mechanical properties.

Abstract Nanocarbons including carbon nanotubes, graphene oxide, reduced graphene oxide and particularly graphene have unique properties such as high mechanical strength, thermally stable, highly conducting, high friction stability and lower specific wear rates, which can potentially provide synergically improved performance of advanced engineering materials and technologies for various fields of applications such as automotive, aerospace, and other industrial components. Development of phenolic resin‐based nanocomposites comprised of nanocarbon material remained as a research focus to outperform different properties of conventional material based components. In application, phenolic resin is the most popular binder in frictional components development such as brake pads, brake linings, and clutch facings, particularly used in many of light and medium automotive brake pad applications. Specifically, the present review study aims to provide thorough discussion on the mechanical, tribological, and thermal performances of phenolic resin‐based nanocomposites containing nanocarbon as a property modifier by comparing with the neat phenolic resin or with the composite containing other micro ingredients. As per presented overview, the analysis shows the significant improvement in some required application‐based properties of phenolic resin‐based nanocomposites such as tensile strength, young's modulus, impact strength, specific wear rate reduction, residue yield, and thermal conductivity due to the inclusion of nanocarbon, where the content of nanocarbons ranges about 0.5 wt% to 5 wt%. Hence nanocomposites synthesized using phenolic resin matrix with nanocarbons fillers found to have better mechanical strength, better wear resistance, and thermal stabilities when compared to pure phenolic resin and other composites.

One of the recent advancements in the field of high temperatureHigh-temperature aluminum alloys high strength aluminum alloysAluminum alloys is the development of the Al-Sc-Zr alloy. The addition of Sc and Zr in the AluminiumAluminium matrix results in trialuminide precipitationPrecipitation that imparts excellent coarsening resistance, making the alloy suitable for high-temperature application. In the early stages of solid–solid phase transformationsPhase transformation, the coherent microstructureMicrostructure is developed by maintaining the continuity between lattice planes and directions along the interface. These misfit strains significantly influence the shape and growth of trialuminides. The temperature dependency of misfit strain, which is often neglected in the theoretical simulationsSimulation of precipitate phases, is considered in the present work to investigate microstructural evolution and resulting strain and concentration field distribution during trialuminide precipitationPrecipitation using the phase-field method. Also, an assessment of the precipitation kinetics during Al3X (X = Sc, Zr) growth in the Al matrix with the help of particle size and energy variation-time graph is also done to get an insight into the precipitationPrecipitation mechanism.

AA7068 is classified as high strength aluminum alloy and is primarily utilized in wrought conditions which can be achieved with hot deformation. The process of hot deformation is a competent way of optimizing material properties; thus, understanding its deformation behavior in the wide range (250-450 degrees C, 10- 3-100 s-1) is vital in processing a high-performance product. The true stress-true strain trend indicated its dependence on thermomechanical variables and precipitate size. The constitutive calculations accurately predicted the flow stress behavior. The kinetic rate calculations demonstrated that glide dislocation motion (with a value of n = 6.3) was observed during hot deformation. 3-dimensional processing map (PM) has revealed a progressive rise in efficiency (& eta;) with increase in true strain. The PM analysis has successfully identified both stable and unstable working regions. Within the stable working region, a peak efficiency (& eta;) of 54% was observed in the range of 347-359 degrees C and 10-3 s-1, 0.69 true strain. In, the stable working region, the microstructural characteristics demonstrated a notable increase in the dynamic softening depending on the process time and deformation temperature. At lower temperatures, the dynamic softening in the deformed specimens predominantly occurred through dynamic recovery (DRV), whereas at high temperatures, it facilitated by dynamic recrystallization (DRX). The DRX during deformation was observed to occur through continuous dynamic recrystallization (CDRX) and particle stimulated nucleation (PSN) mechanism. Hot forging finite element modeling (FEM) exhibited an uneven material flow with the peak effective strain occurring in the core of the specimen. Open forging in the optimum working conditions resulted in the highest tensile strength of 340 MPa, observed at a temperature of 450 degrees C and strain rate of 10-3 s-1.

Elevated temperature isothermal compression of Al-7.3Zn-2.2Mg-2Cu (Al7068) alloy in T6 condition was studied till a true strain of 0.69 in the working temperature and deformation rate range of 250-450 degrees C and 0.001-1 s(-1), respectively. The rheological behaviour of the specimens showed a decrease in the flow stress values at the higher temperature and lower strain rates. The mean deformation activation energy at peak stress was estimated as 266 kJ/mol. 3D processing map suggested two safe working zones (I and II) for the current alloy. Zone I, with a peak efficiency of 57% located in the domain of 288-312 degrees C at 0.001 s(-1), and zone II with an efficiency >= 48% located in the range of 400-450 degrees C and 0.001-0.044 s(-1). The EBSD IPF micrograph of the compression specimens showed a dominance of deformed grains with few fine DRX grains near the grain boundary regions. The analysis showed that the microstructural evolution during hot compression progressed through the CDRX mechanism. TEM analysis confirmed precipitate coarsening with increase in processing temperature and decrease in the deformation rate. (C) 2022 Elsevier B.V. All rights reserved.

Microstructural evolution and resulting stress, strain, and concentration field distribution during Al3X (X=Sc, Zr, Er) precipitation in Al matrix are investigated in this work using the 3D-multi phase-field method. Precipitate particles developed into varying morphology, from cuboidal to spherical, depending on the heat treatment, modulus mismatch, lattice parameter mismatch, and interfacial free energy. The composition distribution and Al-Al3X transformation driving force map identified a difference in precipitation kinetics for each alloy. The precipitation mechanism in the three systems is analyzed in detail with temporal evolution plots of energy components during phase transformation. Al3Er precipitate exhibits the highest growth rate due to Er's high diffusivity and significant lattice parameter mismatch in the Al-Er system. The system has a high chemical and elastic driving force for particle growth, thus attaining quasi-static equilibrium at a relatively lower temperature and time. Therefore, this system observes high magnitude stress, strain, and strain energy field around the Al matrix. The theoretical simulation results obtained from the present study will benefit Aluminium multicomponent alloy design for high strength applications.

In the present work, Al3Zr particles were formed in situ by a reaction between hexafluorozirconate (K2ZrF6) and molten aluminum alloy. The aluminum melt with salt addition was ultrasonically stirred to achieve better dispersion of the particles and refine the cast microstructure. Transmission electron microscopy, x-ray diffraction and scanning electron microscopy were used to characterize the in situ composites. The microstructure was refined due to nucleation of uniformly dispersed Al3Zr particles during melting. The dispersion of Al3Zr particles in the aluminum matrix significantly improved hardness, yield strength, ductility and ultimate tensile strength. Theoretical analysis of the strengthening mechanism revealed that thermal mismatch strengthening is the major strengthening mechanism in these composites.

Impression creep behaviour of Al3Zr/Al composites with varying amounts of Al3Zr particles was studied at different temperatures (543, 573 and 603 K) and stresses (113, 141 and 170 MPa). The uniform distribution of Al3Zr particles throughout the matrix was achieved by ultrasonication during casting. The microstructure of the composites was refined by the homogeneously distributed insitu formed Al3Zr particles. From the creep analysis, it was found that the stress exponent and activation energy values of the Al3Zr/Al composites were higher than that of the base alloy making them more creep resistant. Uniform dispersion of the in-situ Al3Zr particles in the matrix and the clean interface between them played an important role in the improvement of the creep properties of the composites. It was also observed that the creep property of the composites was improved with the increased amount of Al3Zr particles. The calculated activation energy and stress exponent values suggest that the creep mechanism is dislocation climb controlled by lattice diffusion.

Room temperature thermal conductivity values of selected composition of Th-U alloys were experimentally measured employing Transient Plane Source (TPS) technique using slab sample geometry. Experimental values were fitted in an empirical model relating room temperature thermal conductivity with alloy composition. The trend has been explained based on actual microstructural features. The room temperature thermal conductivity values of Th-U alloys were found to be superior to that of other prevailing metallic and ceramic fuel candidates.

Elevated temperature deformation of as-cast aluminum 7068 alloy was done to optimize its workability by physical simulation using Gleeble 3800. The microstructural evolution was traced using electron microscopy and electron back-scattered diffraction studies. Hot deformation involving uniaxial isothermal compression was done in the 300 degrees C-475 degrees C temperature range and 10(-3) -10(0) s(-1) strain rate up to a true strain of 0.69. From the true stress-true strain plot it is observed that flow stress initially increases sharply because of the multiplication of dislocations during the initial phase of deformation; i.e., only work hardening is predominant during this phase. Subsequently, after attaining the peak value the flow stress increases, decreases, or remains constant. Because of dynamic restoration processes such as dynamic recovery and recrystallization, the flow stress decreases or remains constant. During this phase, the competition between work hardening and dynamic softening governs the slope of true stress-strain curve. The decrease in the Zener-Hollomon parameter with increasing temperature and decreasing strain rate follows the same trend as flow stress. Activation energy for this alloy is calculated as 206 kJ mol(-1). The deformed microstructure shows serrated grains, and also well-formed subgrains are observed mostly inside the grains. Moreover, substructural strengthening is observed in this alloy, due to the presence of the high density of precipitates and subgrains. Microstructural analysis confirms the high power dissipation of the stable region may be mainly due to dynamic recovery. In the unstable region, flow instabilities may be due to adiabatic shear band formation, particle cracking, and debonding. The optimized working region is determined from the developed processing map.

In this study, in situ Titanium-tri-aluminide (Al3Ti) particles reinforced Al 6061 alloy matrix composites were fabricated by the reaction of potassium hexafluorotitanate (K2TiF6) inorganic salt with molten Al 6061 alloy via liquid metallurgy route. The development of in-situ Al3Ti particles and their effects on the mechanical properties such as yield strength (YS), ductility, ultimate tensile strength (UTS) and hardness, and microstructure of Al 6061 alloy were studied. It was observed from the results that in-situ formed Al3Ti particles were blocky in morphology whose average size was around 2.6 +/- 1.1 mu m. Microstructure studies showed that grain size of Al matrix was reduced due to the nucleating effect of Al3Ti particles. It was observed from the mechanical properties analysis that when the volume fraction of Al3Ti particles was increased, the hardness, UTS and YS of the composites were also increased as compared to that of Al 6061 alloy. An improvement in ductility was observed with the dispersion of Al3Ti particles in base alloy which is contrary to many other composites.

Al3Ti reinforced Aluminium composites with different weight percent of Al3Ti particles were developed by in-situ reaction of aluminium alloy with potassium hexafluorotitanate (K2TiF6). Ultrasonication of the aluminium melt during salt reaction was carried out to refine the cast microstructure and achieve better dispersion of in-situ formed Al3Ti particles. The in-situ composites were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The Al3Ti particles generated in the melt promoted heterogeneous nucleation, which was responsible for grain refinement of the cast microstructure. The well dispersed Al3Ti significantly improved the mechanical properties including ductility, yield strength (YS), ultimate tensile strength (UTS) and hardness. The dominant strengthening mechanism in the composite was the thermal mismatch strengthening followed by Hall-Petch strengthening.

Health and sustainability are the major concerns that drive researchers to find novel materials to replace artificial hazardous materials. In this investigation, the mechanical properties of Cissus quadrangularis Stem Fiber (CQSF) reinforced with unsaturated polyester composite were optimized by varying the fiber length and content. To substantiate the findings, chemical property, thermal property, microstructure, and water absorption property were analyzed. Progressive enhancement of mechanical properties was observed with increasing the fiber content and fiber length up to 30 wt.% and 40 mm. However, beyond that limit, there was a decline in the strength due to improper bonding of fiber with matrix. Optimal values of mechanical property for CQSF composite were obtained at 30 wt.% fiber content and 40 mm fiber length, which are comparable with that of common artificial fiber-reinforced polymer composites.