Distribution Of Reinforcement Research Articles

Selected challenges in solidification processing of graphene nanoplatelets (GNPs) reinforced aluminum alloys composites

Solidification processing of aluminum graphene composite is an attractive option for synthesis of metal matrix composites. Graphene reinforced aluminum metal matrix composites (GAMMCs) are of interest due to the low density and ultrahigh physical and mechanical properties of Graphene which can improve the properties of Al-Graphene composites. However, solidification processing of aluminum graphene composites has served challenges, including agglomeration of reinforcement and porosity resulting in decrease in properties above 0.five to three wt% graphene. Also, the graphene surface can react with molten aluminum alloys to form aluminum carbide. Challenges with particle distribution and porosity are frequently caused by the poor wetting of reinforcement by melt, requiring additions of selected wetting agents. The other problems include movement of reinforcement within the melt due to density differences and convection leading to nonuniform distribution of reinforcements. The graphene reinforcements can be pushed by solidifying interfaces under certain conditions during solidification leading to segregation of reinforcements in the interdendritic regions. The paper critically analyzes the above problems related to solidification processing of Aluminum- Graphene composites which has not been done in previous publications aluminum-graphene composites. The objective of this paper is to examine the challenges, and suggest possible solutions including addition of elements like silicon and magnesium to aluminum melt, coating graphene with metals like nickel and copper, controlling rate of advancement and nature of advancing solid liquid interface in a manner that they engulf graphene with dendrites or grains.

Effect of carbon nanotubes on mechanical properties of aluminum matrix composites: A review

Abstract Carbon nanotubes (CNTs) are renowned for their low density, high elastic modulus, and exceptional electrical and thermal properties. The continuously developing applications of CNTs provide higher specific stiffness and strength for composite materials. The unique characteristics of CNTs make them ideal reinforcing particles in aluminum matrix composites (AMMCs), which generally exhibit excellent mechanical properties. CNTs/AMMCs are usually prepared using methods such as powder metallurgy, casting, spray deposition, and reactive melting. The uniform diffusion of CNTs in composites is crucial for enhancing the properties of CNTs/AMMCs. The properties of CNTs/AMMCs largely depend on the content, morphology, and distribution of reinforcements in the matrix and the interaction between reinforcements and the matrix. By adding an appropriate volume fraction of CNTs, the hardness, tensile strength, compressive strength, and electrical properties of CNTs/AMMCs were significantly improved. The effects of CNT content on the mechanical properties of CNTs/AMMCs, including the tensile strength, yield strength, compressive strength, stress–strain curve behavior, elastic modulus, hardness, creep, and fatigue behavior, were revealed. The design of microstructure, optimization of the preparation process, and optimization of composition can further improve the mechanical properties of CNTs/AMMCs and expand their application in engineering. The design concept of integrating material homogenization and functional unit structure through biomimetic design of novel gradient structures, layered structures, and multi-level twin structures further optimizes the composition and microstructure of CNTs/AMMCs, which is the key to further obtaining high-performance CNTs/AMMCs. As a multifunctional composite material, CNTs/AMMCs have broad application prospects in fields such as air force, military, aerospace, automation, and electronics. Moreover, CNTs/AMMCs have potential applications in cell therapy, tissue engineering, and other areas.

Effect of Ultrasonic Treatment on Ti/Al Composite using Squeeze Casting: Microstructural Analysis and Mechanical Properties

To segregate the Titanium (Ti) from the reinforcements of the molten scrap of Titanium/Aluminum (Ti/Al) composite, application of ultrasonic vibration is known to be one of the sound techniques. Various studies have been looked at the effect of ultrasonic vibration on the melting process, however not much have been investigated with respect to the solidification process. To fabricate Ti/Al composites in situ, ultrasonic vibration can be effectively used to compress the solidifying melt during the casting process. In this line, the present study focused to investigate the influence of ultrasonic vibration and squeeze pressure on solidification behavior of the α-Al matrix, characteristics of the matrix-reinforcements interface, and distribution of reinforcements. The experimental data indicated that when the amplitude was 60 μm, the Vickers hardness, yield strength, and tensile strength of composites increased by 8.6, 3.9, and 3.1 %, respectively, due to gravity casting. While the squeeze pressure was increased from 50 to 100 MPa, the mean grain size decreased from 90 to 60 μm during the ultrasonic aided squeeze casting (SC) process. However, as the squeeze pressure was raised, the microstructures became coarser and the mechanical characteristics weakened. Yield strength, and tensile strength were increased by 18.7% and 3.2%, respectively, when the squeeze pressure was 100 MPa.

The effect of ratcheting strain on post-ratcheting tensile test of metal matrix composites (MMCs) reinforced by Fe3O4 nanoparticles manufactured by the accumulative roll bonding (ARB) process

This article concerns the effect of strain accumulation during low-cycle fatigue on the post-fatigue tensile behavior of metal matrix composites (MMCs) with identical layers of aluminum reinforced by Fe3O4 nanoparticles produced via the accumulative roll bonding (ARB) technique. Work-hardening behavior, deduced from ratcheting curves, was evaluated by the post-fatigue tensile test. The key finding in the mechanical properties of homogeneous nanocomposite in terms of reinforcement distribution, evolving due to microstructural evolution during the ARB process, is that accumulation of ratcheting strain decreases, and fatigue and post-fatigue tensile behavior significantly increases. The rupture mechanism, analyzed by scanning electron microscope, revealed that deep hemispherical-shaped dimples, a well-known feature of ductile rupture, were changed to elongated shallow shear dimples by the impact of microstructural evolution due to imposed 1000 cycles of ratcheting test.

Strength-Plasticity Relationship and Intragranular Nanophase Distribution of Hybrid (GNS + SiCnp)/Al Composites Based on Heat Treatment.

The distribution of reinforcements and interfacial bonding state with the metal matrix are crucial factors in achieving excellent comprehensive mechanical properties for aluminum (Al) matrix composites. Normally, after heat treatment, graphene nanosheets (GNSs)/Al composites experience a significant loss of strength. Here, better performance of GNS/Al was explored with a hybrid strategy by introducing 0.9 vol.% silicon carbide nanoparticles (SiCnp) into the composite. Pre-ball milling of Al powders and 0.9 vol.% SiCnp gained Al flakes that provided a large dispersion area for 3.0 vol.% GNS during the shift speed ball milling process, leading to uniformly dispersed GNS for both as-sintered and as-extruded (0.9 vol.% SiCnp + 3.0 vol.% GNS)/Al. High-temperature heat treatment at 600 °C for 60 min was performed on the as-extruded composite, giving rise to intragranular distribution of SiCnp due to recrystallization and grain growth of the Al matrix. Meanwhile, nanoscale Al4C3, which can act as an additional reinforcing nanoparticle, was generated because of an appropriate interfacial reaction between GNS and Al. The intragranular distribution of both nanoparticles improves the Al matrix continuity of composites and plays a key role in ensuring the plasticity of composites. As a result, the work hardening ability of the heat-treated hybrid (0.9 vol.% SiCnp + 3.0 vol.% GNS)/Al composite was well improved, and the tensile elongation increased by 42.7% with little loss of the strength. The present work provides a new strategy in achieving coordination on strength-plasticity of Al matrix composites.

Effect of Cetyl Trimethyl ammonium bromide (CTAB) amount on the Nanoindentation creep behaviour of Sn-cu-Y2O3 nanocomposite Lead-free solder

Sn-Cu-Y2O3 nanocomposite solder is synthesized from a citrate bath by pulse electrodeposition route. Y2O3 powder is synthesized from a sol-gel assisted combustion route. Different techniques such as SEM, XRD, and TEM are used to characterize Y2O3 powder. The particle size of Y2O3 powder is found to be 27 nm. The effect of adding cetyl trimethyl ammonium bromide (CTAB) on the synthesis of Sn-Cu-Y2O3 nanocomposite lead-free solder is studied. The amount of CTAB is varied for a particular amount of Y2O3 powder. It is carried out to find the exact ratio of CTAB for better dispersion of Y2O3 powder in the electrolytic bath. Because the distribution of reinforcement in the matrix which is associated with the dispersion of Y2O3 powder in the electrolyte is as important as the amount of reinforcement in the solder matrix. For the synthesis of nanocomposite solder, the optimum ratio of CTAB to Y2O3 is found to be 1:1. After the synthesis of nanocomposite solder, the influence of Y2O3 powder on the melting temperature of the solder is also studied. Incorporating Y2O3 has little effect on the melting point of the nanocomposite solder. Nanoindentation creep test results showed that the deposit at 0.2 A/cm2 (monolithic solder) has a lower creep resistance than the nanocomposite solders. Additionally, the creep resistance of the nanocomposite with a CTAB to Y2O3 ratio of 1:1 was higher.

Desalination setup coated by silicone epoxy nanocomposite: A study on hydrophobic characteristics and condensation mechanisms

The formation of tortuous filmwise condensation in desalination setup alongside with reduction in thermal conductivity is a challenge accompanied by efficiency loss. This issue is directly influenced by hydrophobicity, which is a function of surface roughness, as well as surface chemistry. In this sense, the hydrophobicity of variant silicone epoxy based nanocomposites was evaluated to identify the optimum proportion composite for surface condensation of desalination setup. To this end, three types of fumed silica with distinct surface chemistry were utilized in a matrix at the weight percentage of 0.5, 1, 1.5, and 2. To investigate the hydrophobicity, roughness, and distribution of reinforcement, a series of characterization techniques, including contact angle, AFM, and FESEM were used. It was found that, in comparison to pure matrix, the nanocomposite modified with 5 wt % of hydrophobic additive and 0.5 wt % of hydrophilic fumed silica nanoparticles (SE/5B/0.5R200) has the highest contact angle (about 35%) and roughness (13 times), due to the migration of nanoparticle onto the surface. Also, coating the condensation surface of the desalination setup with optimum thickness, i.e. 60 × 10−6 m, resulted in the efficiency improvement by about 33 % compared to the uncoated setup, even after 168 hrs. Indeed, dropwise condensation, straight path movement of droplets, besides thermal conductivity adjust the efficiency.

High strength and ductility high-entropy intermetallic matrix composites reinforced with in-situ hierarchical TiB2 particles

The design guided by entropy enables the attainment of superior mechanical properties and further extends the concept of high-entropy alloys to intermetallic systems, thus forming high-entropy intermetallic compounds and even high-entropy intermetallic matrix composites. In this study, a novel high-entropy intermetallic matrix composites incorporating in-situ hierarchical TiB2 particles was successfully synthesized through the spark plasma sintering. This method enables precise control over the microstructure, ensuring uniform distribution of the in-situ formed TiB2 particles within the high-entropy intermetallic matrix. The in-situ formation of TiB2 particles is achieved through a reactive sintering mechanism, which not only contributes to the composite's enhanced mechanical properties but also ensures excellent bonding between the precipitates and intermetallic matrix. The composites were composed of the ordered L12 intermetallic matrix and the hierarchical hexagonal-close-packed TiB2 particles. Due to the L12 intermetallic matrix and the heterogeneous distribution of TiB2 reinforcement, the intermetallic matrix composites demonstrate a high ultimate tensile strength of ∼1400 MPa. The TiB2 play a pivotal role in impeding the propagation of cracks and the collaborate with distinctive disordered interfaces at grain boundaries, ensuring enough ductility. The disordered interfaces, exhibiting an average width in the range of 5 nm–10 nm, possess the capability to delay fracture and promote the strain-hardening rate during plastic deformation. The intermetallic matrix composites overcome the limitations typically associated with conventional intermetallics and offer an excellent strength and ductility balance. These findings are expected to formulate additional strategies for designing in-situ reinforcement-strengthened high-entropy intermetallic matrix composites with exceptional mechanical properties.

Multi-objective optimization of machining variables for wire-EDM of LM6/fly ash composite materials using grey relational analysis

Abstract With the enhancement in science and technology, necessity of complex shapes in manufacturing industries have become essential for more versatile applications. This leads to the demand for lightweight and durable materials for applications in aerospace, defense, automotive, as well as sports and thermal management. Wire electric discharge machining (WEDM) is an extensively utilized process that is used for the exact and indented shaped components of all materials that are electrically conductive. This technique is suitable in practically all industrial sectors owing to its widespread application. The present investigation explores WEDM for LM6/fly ash composites to optimize different process variables for attaining performance measures in terms of maximum material removal rate (MRR) and minimum surface roughness (SR). Taguchi’s L27 OA design of experiments, grey relational analysis, and analysis of variance (ANOVA) were employed to optimize SR and MRR. It has been noted from ANOVA that reinforcement (R) percentage and pulse on time are the most influential aspects for Grey Relational Grade (GRG) with their contributions of 28.22 and 18.18%, respectively. It is found that the best process variables for achieving the highest MRR and lowest SR simultaneously during the machining of the composite are gap voltage of 30 V, pulse on time of 10 µs, pulse off time of 2 µs, wire feed of 8 m/min, and R of 9%. The predicted GRG is 0.84, and the experimental GRG value is 0.86. The validation experiments at the optimized setting show close agreement between predicted and experimental values. The morphological study by optical microscopy revealed a homogenous distribution of reinforcement in the matrix which enhances the composite’s hardness and decreases the density.

A Review on Distribution of Reinforcement and tensile Strength of Aluminum Lithium Alloy based Nano Metal Matrix Composites Fabricated by STIR Casting

Aluminum Alloy (AA) parts are employed in lightweight engineering fields and have poor mechanical, wear, and corrosion resistance. Aluminum Matrix Composites (AMCs) are materials created by incorporating hard reinforcing particles into an aluminum matrix alloy. The new material has improved characteristics, including higher specific stiffness and strength, as well as higher corrosion resistance, elastic modulus, wear resistance, and low weight. Metal Matrix Composites (MMCs) are composite materials in which metal serves as the matrix and hard particles or ceramics serve as reinforcement. MMCs are used to improve the functionality of a wide range of technical materials. It could be used in many different fields, including aerospace, automotive, space travel, and medicine. In this paper, the reviewer investigates the distribution of reinforcement and Tensile Strength (TS) of Aluminum Lithium (Al-Li) Alloy/Nano Al2O3 MMC fabricated by stir casting. Finally, the authors provide a comparative analysis of prior reviewed research papers. After comparative analysis, TiB2/2195 composite has higher Tensile Strength (115.4%) than the other composite such as AA7010-TiB2 (260%), Al2O3 + SiC (72%), A356/SiC (21.87%), and Al-SiC (37%).

Study of Mechanical and Tribological Behavior of Fly ash with E-Glass fibre Reinforced AL MMC’s

AMC’s specimen made by liquid stir casting technique, by addition of fixed 3% E-glass fibers and fly ash particles in different proportions (4, 6 and 8 wt.%) prepared the matrix phase. A uniform distribution of reinforcement is obtained with good bonding with matrix. Dry sliding wear behavior of the aluminum alloy and the composites has been studied and tested using a pin-on-disc wear and friction monitor. The testing carried out on sliding velocity of 1.5, 2.5 and 3.5 m/s and load ranges from 1, 2 and 3kgf. The composite shows better mechanical properties than the base alloy. Abrasive wear resistance improves by addition of fly ash reinforcement

The distribution of reinforcements in titanium matrix composites enhanced with graphene: From dispersed to networked

Designing the reinforcement distribution and thus tailoring the matrix microstructure can be leveraged to achieve titanium matrix composites (TMCs) with well-balanced strength and ductility. In this study, through the utilization of mechanical exfoliation to synthesize core-shell structure powders in-situ and spark plasma sintering subsequently, graphene nanoplatelets (GNPs) reinforced Ti6Al4V composites (GNPs/Ti64) with manageable ductility were successfully fabricated. The increasing incorporation of GNPs leads to the reinforcements' transition from dispersed to networked together with the microstructural equiaxialization, which is reflected in a monotonically increasing strength in conjunction with a bimodal distribution of ductility. As a result, both 0.13 wt% GNPs/Ti64 with dispersed reinforcements and 0.70 wt% GNPs/Ti64 with quasi-continuous networked reinforcements possess the well-balanced strength-ductility. This study suggests a practical strategy by regulating the reinforcement distribution for TMCs with attractive properties.

Active vibration control of piezoelectric multilayers FG‐CNTRC and FG‐GPLRC plates

AbstractThis study investigates the active vibration control of multilayer Functionally Graded Carbon NanoTube Reinforced polymer Composite (FG‐CNTRC) plates and multilayer functionally graded graphene platelets reinforced polymer composite (FG‐GPLRC) plates covered with a piezoelectric layer (PZTG1195N) serve as both actuators and sensors. The plate's heart is supposed to be reinforced nonlinearly using both types of reinforcement. Active vibration control of plates under uniform load was achieved by utilizing a velocity feedback control algorithm with a specific gain value. The finite element method is employed to analyze both the static and dynamic behavior of a square plate discretized into 9‐node quadratic finite elements with 5 ° of freedom per node. The material properties are assumed to change across the thickness direction following a power law distribution, exhibiting various patterns: Uniform Distribution (UD), as well as Functionally Graded types X, O, and A (FG‐X, FG‐O, and FG‐A). The geometrical nonlinear equations are solved by the Newmark integration method. This work begins by validating the natural frequencies of a Functionally Graded (FG) composite plate reinforced with four different distributions of Nano‐filler and then aims to show the effect of the nonlinear distribution of nanofillers on the plate's stiffness. The Results obtained after the execution of a developed code highlight the significance of employing a nonlinear distribution of nanofillers to attenuate vibrations.Highlights FG composite and sandwich plates reinforced with GPLs and CNTs. Effect of nonlinear nanofillers distribution of reinforcement on free and forced vibration. The ability of the nonlinear distribution of nanofillers to attenuate forced vibrations.

Static, buckling, and free vibration responses of functionally graded carbon nanotube-reinforced composite beams with elastic foundation in non-polynomial framework

In this work, the static, buckling, and free vibration analysis of functionally graded carbon nanotube-reinforced composite (FG-CNTRC) beam resting on a Pasternak elastic foundation are studied. The secant function-based shear deformation theory (SFSDT) is used for this analysis. This theory fulfills the traction-free boundary conditions at the top and bottom surfaces of the beam, hence there is no need for a shear correction factor. Hamilton’s principle is used to determine the governing differential equations and boundary conditions whereas Navier’s solution technique is used for determining the closed-form solution. The analytical approach is used to examine the deflection, stresses, critical buckling load, and natural frequencies of the FG-CNTRC beam resting on the Pasternak elastic foundation including a shear layer and Winkler springs. To determine the material characteristics of FG-CNTRC beams, the Rule of the mixture is used. Uniform distribution (UD-beam), FG-X beam, FG-O beam, and FG-V beam are the different forms of CNT reinforcement distribution that are used in this study. Considering different span thickness ratios, the volume fraction and distribution of CNT, the Winkler spring, and the shear layer constant factors, all the structural responses are predicted. It is also observed that the present theory predicts the structural responses of the FG-CNTRC beam accurately when compared to other existing theories. A few new results are also included as the benchmark solutions for the new research.

Analysis of wire-cut electric discharge machining behaviour of AA6061 / C / ZrO2 hybrid nano composites using Taguchi’s method

This study focuses on the optimization of wire-cut electric discharge machining (WEDM) process for hybrid metal matrix nanocomposites. AA6061 alloy reinforced with graphene (C) and zirconia (ZrO2) was fabricated through the stir casting method with ultrasonic assistance for three different weight proportions: 92% AA6061 / 3% C / 5% ZrO2, 87% AA6061 / 3% C / 10% ZrO2, and 82% AA6061 / 3% C / 15% ZrO2. Microstructural examination confirmed the uniform distribution of reinforcements in the matrix alloy. The fabricated composite was machined by WEDM using an L27 orthogonal array designed by Taguchi’s method. Four electrical control factors of pulse on-time, pulse off-time, wire feedrate and peak current were considered, along with one reinforcement factor and three output responses: kerf width, surface finish and material removal rate to analyse the machining behaviour. Analysis of Variance was performed to determine the significant parameters. The results revealed that the most significant factor is pulse on-time among the five different factors. Optimized parameters were identified and examined through confirmation experiments resulting in improved machining characteristics.

Effect of Yttria-Stabilized Zirconia addition along with Cu in development of titanium based metal matrix composite via FSP technique for the application in biomedical devices

ABSTRACT The present study investigated the effect of incorporating Yttria-Stabilized Zirconia (YSZ) and copper (Cu) in the development of Titanium-Based Metal Matrix Composites (TMCs) using the Friction Stir Processing (FSP) technique. The macrostructure of the TMCs, after adding 5% YSZ and 2% Cu, displayed a defect-free, crack-free, and porosity-free surface, indicating the precision of the FSP method. Microstructure analysis revealed a uniform distribution of reinforcement particles and proper dispersion of grains, key for enhancing mechanical properties. The interfacial bonding between titanium and YSZ was exceptionally strong, devoid of cracks and porosity, attributed to the copper additive’s role. The increase in the number of grains per square inch for the Ti/5% YSZ/2% Cu composite (1176.26 grains per square inch at 500×) signified finer grain structure, contributing to a remarkable 48.04% improvement in tensile strength compared to pure titanium. The uniform distribution of reinforcement and strong bonding between titanium and YSZ are the driving forces behind the 46.34% increased in hardness. Additionally, the wear resistance of the composite improved by approximately 76.66%, a vital characteristic for applications facing abrasive conditions. The corrosion testing demonstrated an 8.33% enhancement in corrosion resistance with the Ti/5% YSZ/2% Cu composite.

Synthesis mechanism of pelleted heterostructure Ti64–TiB composites via an interdiffusion and self-organization strategy based on powder metallurgy

Titanium matrix composites (TMCs) are the most attractive next-generation structural materials for lightweight design due to their high specific modulus and specific strength. Designing heterogeneous grain structures has been a widespread strategy for overcoming the strength-ductility trade-off in powder metallurgical TMCs. However, achieving a customizable heterogeneous grain structure in TMCs remains a formidable challenge. Here, we propose a novel interdiffusion and self-organization strategy based on the powder metallurgy method to fabricate a pelleted heterostructure Ti6Al4V(Ti64)–TiB composites, which integrates a heterogeneous distribution of reinforcements and heterogeneous grain structures of the matrix. The study reveals that the formation of the pelleted heterostructures is primarily governed by the interdiffusion reaction process between Ti and Al, and V elements, coupled with the growth and distribution changes of TiB induced by the interdiffusion reaction. Moreover, the pellet size is tailored by the spherical Ti–TiB composite powder, allowing precise control over the heterogeneous grain regions. This research contributes valuable insights into the manufacturing process of pelleted heterostructure Ti64–TiB composites and provides a conceptual framework applicable to the design of similar structures in various metal matrix composite systems.

Assessment of machinability behaviour of LM24 – nano Al2O3 – gr hybrid composites through stir casting technique

Abstract This study is focused on developing a novel combination of a hybrid MMC made of LM24 aluminium alloy, nano Al2O3 and Graphite for enhanced machinability. The study conducts a series of experimental runs and evaluates surface roughness and material removal rate. The process parameters of spindle speed, feed, and depth of cut have been varied, while different weight percentages of nano Al2O3 (1%, 3%, and 5%) were incorporated into the LM24 metal matrix alloy along with 1 wt% of Gr. Response Surface Methodology (RSM) is used to optimize the turning parameters and enhance the machining performance for better quality and productivity. The derived optimal machining parameters have been verified through confirmatory tests. An analysis of variance (ANOVA) was used to determine the individual contributions of each parameter to the machinability characteristics. Surface morphology analysis revealed the uniform distribution of nanoparticle reinforcements in the metal matrix. The surface roughness and material removal rate of the machined nanocomposites were studied. The optimized outputs are a minimum surface roughness Ra 0.522 μm and maximum material removal rate MRR 110.2 mm3s–1 The maximum hardness of the MMC composites has been 60.5 HRB.

Vibration characteristics of multilayer functionally graded microplates with variable thickness reinforced by graphene platelets resting on the viscoelastic medium under thermal effects

Due to their improved mechanical properties and adaptability, microplates with tailored variable thickness profiles are becoming essential parts of advanced micro- and nanoelectromechanical systems (MEMS and NEMS). This study conducts a thorough analytical analysis of the vibration properties of thermally loaded, multilayer functionally graded graphene platelet-reinforced composite (FG-GPLRC) microplates of linearly or parabolically varying thickness resting on viscoelastic medium under different boundary conditions. The Halpin–Tsai micromechanical model and the law of mixtures are employed to calculate the effective material characteristics for various reinforcement distributions in the microplate. These distributions encompass uniformly symmetric and asymmetric arrangements. The study utilized the first-order shear deformation theory (FSDT) in conjunction with the modified strain gradient theory (MSGT) and Hamilton's principle to generate the dynamic governing equations for the structure, accounting for size-dependent effects. The resulting equations are afterwards solved using the utilization of the Galerkin technique. This enables the evaluation of the proposed solution's correctness and precision. The impact of various factors on vibration behavior is investigated through numerical analysis. These factors encompass length scale parameters, temperature fluctuations, temperature distribution profiles, boundary conditions, the distribution pattern of the GPL, taper constants in both unidirectional and bidirectional scenarios, the weight fraction of the GPL.

Microstructure and tribological behaviour of CoCrCuFeTi high entropy alloy reinforced SS304 through friction stir processing

Surface modification by suitable technique aids in improving the characteristics of material to resist severe wear in demanding environments and challenging applications. The present study aims to analyse the tribological performance of Stainless Steel (SS304) reinforced with CoCrCuFeTi High Entropy Alloy (HEA) through friction stir processing and compares the results with annealed specimens. The CoCrCuFeTi HEA was ball milled and revealed irregular fragment particles with Body Centred Cubic (BCC) phase. The processed samples exhibited excellent refinement in grains with uniform HEA reinforcement distribution. The grains were observed to be in nano level post-annealing promoting exceptional microhardness. The pin-on-disc wear test was conducted by varying load (10-40N), sliding velocity (0.5–3.5 m/s) and sliding distance (500–2000 m) and the respective worn surface was analysed. The processed sample with HEA after annealing offered 29.8%, 57.4% and 58.49% improved wear resistance at the minimum level of load, sliding velocity and sliding distance than the processed base samples. The worn morphology revealed delamination, abrasion, adhesion and oxide layer formation to be the predominant wear mechanisms.