Distribution Of Reinforcement Research Articles

Influence of pin thread on particle distribution in the FSP using the CEL method

Material flow pattern determination during Friction Stir Processing (FSP), while producing a composite substrate is one of the most challenging factors in achieving uniform distribution of reinforcements. This article investigates the effects of pin thread and thread pitch on the distribution of reinforcing particles during the FSP process. It is more challenging when complicated pin designs, including threads, are employed due to the limitations of the numerical model development. To comprehensively evaluate the influence of various tool pin designs on material flow, particle distribution, temperature, and strain, the study employs the Coupled Eulerian-Lagrangian (CEL) modeling technique. Three distinct tool designs with thread pitches of 0.75 mm, 1 mm, and 2 mm were analyzed for their impact on these parameters. The results indicate that samples produced with threaded tools exhibit higher temperatures and strain levels than those processed with circular tools. Moreover, the circular tool design does not facilitate a uniform distribution of particles within the processed zone. Notably, threaded pins with pitches of 0.75 mm and 1 mm effectively promote a more uniform arrangement of particles within the base matrix, enhancing the overall processing outcomes.

Microstructures and Mechanical Properties of Al Matrix Composites Reinforced with TiO2 and Graphitic Carbon Nitride

The scattering of reinforcement plays a crucial role in the microstructure and properties of metal matrix composites. In this study, an aluminum matrix composite (AMC) was reinforced by 10 wt% TiO2 (Al-10TiO2), with an average particle size of a submicron, combined with a different content of graphitic carbon nitride (g-C3N4), which was fabricated by shift-speed ball milling (SSBM) combined with multi-pass friction stir processing (FSP). In addition to the high hardness of TiO2, g-C3N4 has functional groups to promote in situ reactions. SSBM improves the distribution of reinforcement, refines grain size, and reduces the structural destruction of g-C3N4. The in situ reaction was achieved after multi-pass FSP at a high rotational speed and low travel speeds, which can promote uniform dispersion and grain refinement. Moreover, the g-C3N4 shows the efficient enhancement of strength while maintaining the elongation of AMC. Because the exfoliation of g-C3N4 under the effect of processing reduces the agglomeration of TiO2, boosts the flattening of Al, and enhances interface integration with the base metal. In situ phases can reduce the generation of coarse phases and improve interfacial bonding ability to enhance mechanical properties. The maximum tensile strength has been found at about 172.5 MPa in the Al-10TiO2 containing 1 wt% g-C3N4, which was enhanced by 34% compared to that of the Al-10TiO2. The tensile strength increases when the g-C3N4 content increases from 0 to 1 wt%, but then reduces with a further increase of content. The hardness was increased by 50.2%, 60.2%, and 35% with a g-C3N4 content of 0.5, 1, and 2 wt% compared to AMCs without reinforcement, respectively. According to the test, the enhancement mechanism is mainly attributed to Orowan, grain refinement strengthening, and load transfer of scattered reinforcement. In summary, the utilization of hybrid reinforcements successfully enhances the microstructure and mechanical properties.

Influence of Varying Particle Size on Mechanical & Tribological Properties of A356-Al2O3 Metal Matrix Composites

MMCs represent a new generation of engineering materials in which a strong ceramic reinforcement is incorporated into a metal matrix to improve its properties including specific strength, specific stiffness, wear, corrosion resistance and elastic modulus. Aluminium oxide and silicon carbide powders in the form of fibers and particulates are commonly used as reinforcements in MMCs and the addition of these reinforcements to aluminum alloys has been the subject of a considerable amount of research work. Aluminum oxide and silicon carbide reinforced aluminum alloy matrix composites are applied in the automotive and aircraft where the tribological properties of these materials are considered important. Therefore, the development of aluminum matrix composites is receiving considerable emphasis in meeting the requirements of various industries. An economical way of producing metal matrix composite is the incorporation of the particles into the liquid metal and casting which leads to improvement in strength over the unreinforced alloy. Addition of particulate reinforcement improves stiffness, strength and tribological properties. Particle size also influences the uniformity of distribution of reinforcement in the matrix. Smaller the particle size, higher will be the agglomerate content in the composite structure. Particle also directly influences the porosity content in the composite structure.The purpose of research in Tribology is understandably the minimization of losses resulting from friction and wear at all levels of technology where the rubbing of surfaces is involved. The present work is a small attempt made to study the influence of reinforcement particulate size on the mechanical and tribological characteristics of Al-Al2O3p composites.

High-temperature spark plasma sintering of h-BN composites reinforced with carbon nanotubes, carbon fibers, and graphene nanoplates

In this study, two h-BN-based composites reinforced with carbon fibers (CF) and carbon fibers/carbon nanotubes (CNTs)/graphene nanoplates (GNPs) have been produced successfully through a high-temperature spark plasma sintering. 1 Wt.% short carbon fibers (length of 5 mm) with 0.1 Wt.% of CNTs and also 0.1 Wt.% of GNPs as hybrid composite were mixed through a simple mixing method including a high energy sonicating and stirring on the hot plate in ethanol media until drying. Moreover, h-BN/1 Wt. % CF composite was mixed with a similar method to compare impacts of CNTs and GNPs addition on the mechanical properties and microstructure of h-BN/CF composite. The high-temperature spark plasma sintering processes were performed at vacuum conditions of almost 20-25 MPa with a starting pressure of 10 and a final applied pressure of 50 MPa at a maximum temperature of 1900˚C. Both prepared samples showed near full densification of higher than 98.1 % of the theoretical density determined by Archimedes’ principle. Investigation of the crystalline phases by XRD represented only related peaks to h-BN. The FESEM images indicated an almost uniform distribution of reinforcement in the h-BN matrix. Furthermore, the polished surface of the provided samples showed only the pulled-out carbon fibers effects while the fracture surfaces confirmed the presence of CF and it’s tunneling effects. The obtained mechanical properties revealed 273±12 MPa of bending strength, 1.32±0.1 GPa of Vickers hardness, and 4.79±0.2 MPa.m0.5 fracture toughness for the prepared hybrid composite.

Mechanical and tribological properties of AA2024 reinforced Al2O3 and ZrO2 hybrid composite

Abstract Hybrid Metal Matrix Composite (HMMC) alloys are a very attractive material for excellent mechanical and tribological performance, and their properties can be easily customized by varying reinforcement types and amounts. This research investigated the mechanical and tribological properties of an Aluminium Alloy (AA) 2024 reinforced with 2 wt% Al2O3 and (2, 4, 6) wt% ZrO2 hybrid composites. The presence and distribution of reinforcements in the stir-casted samples were confirmed by SEM, EDS, and elemental mapping. The tribological tests were conducted on a pin-on-disc under dry and wet conditions using Taguchi’s L9 orthogonal array. The SAE 20w40 oil and SAE 20w40 oil mixed with TiO2 nano additive are lubricants. The hardness and tensile strength increase linearly with the addition of a single and continue to increase with multiple reinforcements. The HMMC exhibits a maximum hardness and tensile strength of 107 BHN and 209.281 MPa, respectively. The experimental results show that the dry condition’s wear rate is much higher than that of the composites lubricated with SAE 20w40, especially SAE 20w40 with TiO2 nano additive. Compared to the base material, AA2024 reinforced with 2 wt% of Al2O3 and 6 wt% of ZrO2 exhibited an enhanced wear resistance of 0.0002353 mm3/min and COF of 0.118 with nano lubricant which is 40% and 21% higher than base lubricant.

Simultaneously enhancing strength and ductility in boron nitride nanosheets reinforced TA15 composites via gradient reinforcement distribution

Simultaneously enhancing strength and ductility in boron nitride nanosheets reinforced TA15 composites via gradient reinforcement distribution

Experimental investigation on the cyclic behaviour of full-scale reinforced concrete columns under biaxial shear loading

Although reinforced concrete (RC) elements frequently undergo biaxial shear forces, limited experimental investigations on RC elements subject to biaxial shear have been conducted, and studies about the different types of biaxial shear failure (i.e., flexural-shear and brittle shear) are even scarcer. The focus of this experimental study is on the flexural-shear and the shear failure modes of shear-deficient full-scale RC columns tested under constant compression and subject to an oblique cyclic lateral load with respect to the principal axes of the cross-section. Twelve columns with square and rectangular cross-section have been tested by applying the shear load along different directions. A comprehensive set of experimental data is critically presented to investigate the effect of biaxial loading condition on damage patterns, strain distribution of longitudinal and transverse reinforcement, force–displacement curves of the columns, shear capacity, displacement ductility, stiffness and energy dissipation. It has been found that: i) biaxial loading condition affects the cracking morphology and distribution, as the cracks appear steeper and denser for columns subjected to uniaxial loading, and diffused and more gradually inclined for columns subjected to biaxial loading; ii) stirrups being more parallel to the loading direction are more prone to yield than orthogonal ones, while yielding of longitudinal bars occurs subsequently under biaxial loading; iii) the quadratic interaction domain underestimates the shear capacity of brittle shear columns with low amounts of stirrups by around 10%; iv) the quadratic interaction domain provides reasonable predictions of the displacement capacity under biaxial shear.

Synergistic effects of boron carbide and eggshell particles on mechanical and tribological properties of ultrasonic-assisted stir cast aluminium alloy based composites

Aluminium matrix composites are in high demand for their lightweight nature and favourable properties, yet issues like high thermal expansion, low microhardness or high cost often challenge them. To address these limitations, the integration of sustainable, cost-effective reinforcing agents that can enhance hardness and wear resistance can be explored, as this can broaden the application scope of these composites across various industries. The present study fabricates aluminium matrix composites with aluminium alloy (AA6063-T6) as a matrix and different wt.% (0%, 2% and 4%) of micro-sized eggshell (ES) and boron carbide (B4C) particles as reinforcements through ultrasonic-assisted stir-casting. Analysis of microstructure, mechanical and tribological properties of the fabricated composites are done and compared to those of the as-cast base alloy. Results from optical and scanning electron microscopy (SEM), together with energy-dispersive X-ray spectroscopy (EDS) analysis, revealed the uniform distribution of reinforcements in all three composites. X-ray diffraction (XRD) indicated the formation of several compounds in each composite. Among all, the as-cast base alloy exhibited the lowest porosity at 0.48%. The AA6063-T6/B4C composite demonstrated the highest hardness, with an increase of 46.08%, while the AA6063-T6/ES/B4C composite achieved the highest tensile strength, showing a 62.28% improvement compared to the as-cast base alloy. As the load increased from 20N to 60N, the wear rate of the reinforced composites rises while the coefficient of friction decreased, with the AA6063-T6/B4C composite showing the highest wear resistance.

Vibration Characteristic Analysis of Sandwich Composite Plate Reinforced by Functionally Graded Carbon Nanotube-Reinforced Composite on Winkler/Pasternak Foundation

This paper presents numerical investigations into the free vibration properties of a sandwich composite plate with two fiber-reinforced plastic (FRP) face sheets and a functionally graded carbon nanotube-reinforced composite (FG-CNTRC) core made of functionally graded carbon nanotube-reinforced composite resting on Winkler/Pasternak elastic foundation. The material properties of the FG-CNTRC core are gradient change along the thickness direction with four distinct carbon nanotubes reinforcement distribution patterns. The Hamilton energy concept is used to develop the equations of motion, which are based on the high-order shear deformation theory (HSDT). The Navier method is then used to obtain the free vibration solutions. By contrasting the acquired results with those using finite elements and with the previous literature, the accuracy of the present approach is confirmed. Moreover, the effects of the modulus of elasticity, the carbon nanotube (CNT) volume fractions, the CNT distribution patterns, the gradient index p, the geometric parameters and the dimensionless natural frequencies’ elastic basis characteristics are examined. The results show that the FG-CNTRC sandwich composite plate has higher dimensionless frequencies than the functionally graded material (FGM) plate or sandwich plate. And the volume fraction of carbon nanotubes and other geometric factors significantly affect the dimensionless frequency of the sandwich composite plate.

The High-Strain-Rate Impacts Behaviors of Bilayer TC4-(GNPs/TC4) Composites with a Hierarchical Microstructure.

Ti matrix composites (TMCs) are promising structural materials that meet the increasing demands for light weight the automobile and aircraft industries. However, the room temperature brittleness in the traditionally homogeneous reinforcement distribution of TMCs limits their application in high-strain-rate impact environments. In the present study, novel bilayer TMCs with hierarchical microstructures were designed by the laminated combination of graphene nanoplatelet (GNPs) reinforced TC4 (Ti-6Al-4V) composites (GNPs/TC4) and a monolithic TC4. Meanwhile, the configuration of the microstructure, impact performance V50, and deformation modes of the bilayered TC4-(GNPs/TC4) plate was investigated. The plates were fabricated via field-assisted sintering technology (FAST). It turned out that the TC4-(GNPs/TC4) plate with a 7.5 mm thickness against a 7.62 mm projectile exhibited greater impact performance (V50~825 m/s) compared to the TC4 and GNPs/TC4 single-layer plates. The plate failure modes were dependent on the microstructure while the failure behaviors seemed to be influenced by the hierarchical configuration. This work provided a new strategy for utilizing TMCs in the field of high-strain-rate impact environments.

Mechanical and electromagnetic interference shielding properties of in-situ grown Si3N4nw synergistic defective-graphene reinforced alumina ceramics

Ceramic matrix composites have versatile application potential but are astricted by brittleness and single function. It can be ameliorated assisted by reinforcements, but the uneven distribution of reinforcements seriously limits the reinforcing efficiency. In this work, the layered porous skeleton of alumina (Al2O3) and silicon dioxide (SiO2) was prepared, then defective-graphene (DG) and silicon nitride nanowires (Si3N4nw) were successively grown in-situ in the skeleton (Al2O3/SiO2-G-Si3N4nw) to concurrently strength and toughen, as well as endow Al2O3 ceramic with electromagnetic interference (EMI) shielding performance. Subsequently, Al2O3/SiO2-G-Si3N4nw preform was sintered to construct a uniform Si3N4nw synergistic DG enhancement network. The optimum flexural strength and fracture toughness of the sintered ceramic reached 388.52 MPa and 11.29 MPa m1/2, respectively. This was mainly since DG can fine the ceramic grains, induce crack deflection and furcation, while the uniformly distributed Si3N4nw consumed additional energy during the pull-out process. In addition, the EMI shielding effectiveness of the sintered ceramics in X-band was up to 31.77 dB, which is mainly attributed to the conductive loss, dipole polarization loss and interfacial polarization loss of DG. Remarkably, this work provides an idea for efficient strengthening, toughening and integration of structure and function.

Synthesis, characterisations and applications of boron nitride based hybrid metal matrix composites

ABSTRACT This study focuses on how reinforcements impact the base material (specifically AA 6082) regarding its microstructure, mechanical behaviour& corrosion behaviour. Boron nitride (BN) & molybdenum disulphide (MoS2) employed as reinforcing materials ranged from 1% to 3% of BN & 1% to Constant MoS2. The composite materials were produced utilising the stir casting technique. X-ray diffraction (XRD), scanning electron microscope (SEM) with Energy Dispersive spectroscopy (EDAX) & an optical microscope (OM) were used to examine microstructural phase identification analysis. Tensile, compressive, impact, density& porosity fracture mechanisms were investigated by mechanical testing. BN & MoS2 reinforced particles’ presence in the samples is confirmed by XRD and microstructural pictures showing consistent matrix reinforcement distribution. According to the findings, incorporating BN & MoS2 reinforcements improved the mechanical & corrosion properties but slightly reduced the impact strength. The fractured samples revealed micro cuts, micro ploughing, cracks, trans-granular cleavage facets, dimples in the tensile & impact tests. Reduction in Corrosion rate was achieved gradually by adding reinforcement particles for the composites.AA6082, 3 wt: % BN, & 1 wt.% MoS2 composites have shown a decrease in corrosion current density by 1.901 mA/cm2 & an increase in charge transfer resistance by 99.934 Ω cm-2, attributed to passivation.

Influence of heat treatment on metallurgical and mechanical properties of aluminium Al6061 hybrid metal matrix composites

Abstract The current investigation explores the metallurgical and mechanical properties of hybrid metal matrix composites (HMMC) with aluminum 6061 as the base material, reinforced with ceramic of tungsten carbide (WC) nanoparticles, graphite (as a solid lubricant) and redmud (RM). Four different composites with tungsten carbide nanoparticles (1.5 wt.%) and graphite (2 wt.%) with a varying proportions of redmud (0, 1, 3 and 5 wt.%) are fabricated by stir casting. Microscopic analysis reveals grain boundary with segregations, some of which dissolve to form discontinuous grain boundaries after heat treatment. FESEM examination shows the formation of intermetallic, some of which dissolve on heat treatment to form precipitate that are distributed evenly along the grain boundary and also inside grains. EDX mapping further validated the uniform distribution of reinforcements without any agglomeration. The addition of reinforcements and heat treatment (T6) resulted in substantial improvements in hardness, ultimate tensile strength, yield strength, and compressive strength compared to unreinforced Al6061 and untreated HMMC, respectively. Fractographic analysis of tensile tested samples reveals the presence of dimples, tearing edges and small voids, indicating ductile fracture.

Synthesis and characterization of Ni-based infiltration brazed coating reinforced with Co-P shell-coated WC

In this work the interface and wear resistance of Ni/WC infiltration-brazed cladding was increased by incorporating WC@Co-P reinforcements. This was achieved by depositing a Co-P nano-shell on the WC particles using the electroless plating technique. The morphology of the powders and the thickness of the Co-P shell were examined using field emission scanning electron microscopy (FESEM) and transmission electron microscopy (TEM), respectively. The phase compositions were analyzed through energy-dispersive X-ray spectroscopy (EDS) and X-ray diffraction (XRD). The results revealed that by optimizing the parameters of the electroless plating bath, a uniform Co-P shell with an average thickness of 80 nm was successfully deposited onto the WC particles. Through FESEM and EDS analyses, it was observed that the WC@Co-P/NiCrBSi coating exhibited higher compactness compared to conventional Ni/WC coating, along with a more homogeneous distribution of reinforcements. Additionally, unlike WC/NiCrBSi coating, no abnormal growth of particles occurred during molten phase sintering. Underpinning these findings are results from Pin-On-Disk tests which demonstrated notable improvements in various wear properties for the Co-P modified coating compared to conventional Ni/WC coating. Specifically, there was a 33 % increase in the coefficient of friction (0.3), a 40 % reduction in wear rate (0.006 g/Km), and a 26 % increase in hardness (1500 Vickers). These enhancements highlight the potential benefits offered by incorporating WC@Co-P reinforcements in improving interface quality and wear behavior for Ni/WC infiltration-brazed coating materials.

Enhancing wear resistance of aluminum 6061 composites with fly ash: A sustainable approach for industrial applications

This study investigated the benefits of adding fly ash as a reinforcement material. The benefits included cost-effectiveness, improved quality, isotropic behavior, and environmental advantages. To improve self-lubrication and wettability behavior, Al6061 alloy composites were fabricated with different amounts of fly ash (0%, 2%, 4%, 6%, and 8% by weight), along with a fixed amount of graphite (3wt.%) and magnesium (2wt.%). Wear tests were conducted using Taguchi’s Design of Experiment (DoE) approach on the composites. The optimized composition with 6% fly ash exhibited the least wear rate under the test conditions of load = 10 N, sliding velocity = 3 m/s, and sliding distance = 2 km. SEM images revealed a uniform distribution of fly ash and graphite reinforcement in the matrix, contributing to enhanced wear resistance. The composites exhibited fewer scratches and plastically deformed surfaces, indicating a decrease in wear rate and increased wear resistance with higher fly ash content. ANOVA were used, and four parameters were identified to be critical, Composition at 34%, Sliding Distance at 27%, load at 23%, and Sliding Velocity at 12% contribution with a statistical confidence of 95%. This research contributes to developing cost-effective and environmentally sustainable materials with improved mechanical properties. It makes them suitable for various industrial applications, such as the automotive industry, where wear resistance is essential.

Fundamental approach to superior trade-off between strength and ductility of TiB/Ti64 composites via additive manufacturing: From phase diagram to microstructural design

Reinforcement distribution tailoring has been proven effective in strengthening and toughening titanium matrix composites (TMCs). In this work, the analysis of the Ti64 (Ti-6Al-4V)-B phase diagram indicated that B content dominates the TiB distribution. With this philosophy, B content regulation was applied to tailor homogeneous and network structures in Ti64-B composites fabricated via laser-directed energy deposition additive manufacturing (AM). The unique plate-like TiB attends inhomogeneous composites (Ti64-0.05B). However, in network composite (Ti64-0.25B), the TiB whisker (TiBw) arranges along prior β-Ti grains with the same orientation. Moreover, the synergistic improvement of strength (988 MPa → 1202 MPa), stiffness (106 GPa → 116 GPa), hardness (325 HV → 362 HV), and uniform elongation (5 % → 7.8 %) were achieved. This work exhibited a balanced strength/ductility trade-off, which provides a good guide on microstructure tailoring.

Investigating the Tribological Behavior of Bioinspired Surfaces in Agro-waste and Alumina Reinforced AA6063 Matrix Composites

The tribological behavior of three bioinspired (BI) agro-waste ashes—bean pod ash (BPA), cassava peel ash (CPA), and coconut husk ash (CHA)—integrated as reinforcements in an alumina-reinforced AA6063 matrix hybrid and monolithic composite was investigated. Studies utilizing agro-wastes for bioinspired surfaces are limited despite these wastes posing significant environmental challenges. Consequently, there has been a growing effort to valorize these residues for sustainable engineering applications. This study uses a two-step stir-casting methodology to engineer bioinspired materials with lightweight properties, exceptional hardness, and wear-resistant characteristics. Microstructural investigations revealed a homogeneous distribution of natural and synthetic reinforcements within the AA6063 matrix. Lightweight AMCs were successfully fabricated, exhibiting densities ranging from 2.57 to 2.74 g/cm³ and hardness values between 81.28 and 107.47 BHN. The average surface roughness of these composites varied from 2.4 to 3.4 μm, with ANOVA tests confirming a statistically significant difference (p < 0.005). Wear rates and the coefficient of friction were observed to range from 2.52 x 10-3 to 5.50 x 10-3 mm³/m and 0.2476 to 0.5403, respectively. Reinforcing the AA6063 alloy with bioinspired agro-wastes significantly enhanced the hardness and tribological performance of the as-cast BI-AMCs. Notably, the wear rates and friction coefficients were significantly reduced, with the monolithic BI-AMCs demonstrating superior results. Furthermore, adding bioinspired agro-wastes, such as BPA, CPA, and CHA, improved the surface texture of AA6063 more effectively than Al2O3, leading to slightly smoother surfaces. These nuanced bioinspired tribological behaviors present opportunities for tailored load-bearing and aesthetic applications derived from agro-waste-based composites. This study advances our understanding of bioinspired tribological phenomena and paves the way for the development of innovative materials with diverse applications and enhanced performance.

Free Vibration of Carbon Nanotube Reinforced Functionally Graded Shells

The main objective of this research is to investigate the vibration patterns of cylindrical panels composed of epoxy composites containing functionally graded Multiwall Carbon Nanotube (FG MWCNT). The research specifically addresses the issue of resonance failure, which is common in lightweight polymer composite structures that are subjected to dynamic forces. Curved components used in aircraft, automobiles, and marine vehicles, i.e. curved panels, conical shells, open shells and circular cylindrical shells, are particularly susceptible to this type of failure. The ANSYS software was used to consider three different types of uniaxial reinforcement distribution for modelling cylindrical panels made of FG-MWCNT epoxy composites. The extended rule of mixture of a micromechanical model is employed to determine the distribution of carbon nanotubes transversely the thickness of the structure, utilizing effective parameters. The research examines the impact of various geometrical considerations, such as the volume fraction of carbon nanotubes (CNTs),length to thickness ratio and boundary conditions on the analysis of vibration of the shell structure. The outcomes obtained from the suggested Finite Element Method (FEM) are obtainable to validate the performance and usefulness of the model.

Enhanced microstructures, mechanical properties, and machinability of high performance ADC12/SiC composites fabricated through the integration of a master pellet feeding approach and ultrasonication-assisted stir casting

Integrating ceramic particles into aluminum matrices poses significant challenges due to their limited wettability and high specific volume ratio. This research focused on developing ADC12/SiC aluminum composites with varying SiC concentrations (1.5, 2.5, and 3.5 wt%) through an innovative fabrication process. Initially, ADC12/SiC master pellets containing a high concentration of homogenously dispersed 1-μm SiC particles were produced. Subsequently, these master pellets were introduced into the molten ADC12 alloy, followed by the dispersion of SiC particles via stir casting assisted by ultrasonication. The study assessed the impact of SiC weight fractions on the microstructures, mechanical properties, and machinability of the fabricated composites. The results revealed significant microstructural improvements and a more even distribution of SiC reinforcement inside the ADC12 matrix after the application of this innovative processing method. Increased SiC concentration led to notable refinement of α-aluminum grains and eutectic Si, as well as a more uniform dispersion of intermetallic phases. Additionally, a substantial increase in tensile properties and hardness was observed with the increment of SiC content. Particularly, the ADC12/3.5 wt%SiC composite exhibited a 46.73% increase in hardness and notable enhancements in yield strength, ultimate tensile strength, and elongation, denoted as 201.7 MPa, 241.1 MPa, and 3.40%, respectively, as compared with those of the unreinforced ADC12 alloy. Moreover, the ADC12/SiC composites demonstrated reduced surface roughness compared to the unmodified ADC12 alloy, indicative of a superior surface finish. With the addition of a high SiC content, the chip morphology was observed to change from continuous to discontinuous following a turning operation.

Development and characterization of a novel AA6061 composite reinforced with titanium aluminide via friction stir processing

Current research work emphasizes on the development of particulate titanium aluminide (TiAl), an intermetallic class of material, through mechanical alloying (MA) from elemental powders and usage of same as reinforcement in AA6061 aluminum matrix to enhance its mechanical and tribological performance. TiAl, being a light weight, strong and abrasion-resistant material, is found to be a suitable candidate to replace dense ceramic-based reinforcements in aluminum composite. Friction stir processing (FSP), a well-established surface severe plastic deformation tool, is used to develop the composite in this study. Several strategies on improving the stirring action and particle distribution during FSP is employed and their scientific effect is studied in detail. Microstructural evolution was studied through scanning electron microscopy (SEM) combined with electron backscattered diffraction (EBSD) analysis which revealed uniform particle distribution of reinforcement in the friction stir processed (FSPed) zone with 88.23 % reduction in grain size of composite as compared to base material. Hardness studied showed an increase in the hardness by 33 % for composite material as compared to un-reinforced FSPed material, showing the positive effect of reinforcement alone on the mechanical strength of the material. Tensile results showed an improvement in yield tensile strength from 156 MPa in base to 186.8 MPa in the composite material without significant compromise in the ductility 26.86 % for composite and 28.14 % for base. Mechanisms aiding uniform particle distribution, and the reasons for improvement in mechanical performance of the developed composite is discussed in detail with the help of microstructural studies and post-deformation fractograph.