Showing papers by "Prasanta Sahoo published in 2021"

Nano-indentation and Corrosion Characteristics of Ultrasonic Vibration Assisted Stir-Cast AZ31–WC–Graphite Nano-composites

Abstract: Current study investigates the effect of graphite nanoparticles on nanoindentation behavior and corrosion characteristics of Mg–WC nanocomposites. Composites are developed by ultrasonic treatment associated stir casting method. Typical characterizations of nanocomposites are conducted using optical microscopy and scanning electron microscopy. Compositions of as cast materials are examined using energy dispersive X-ray analysis. Nanoindentation tests are conducted to expose elastic modulus and nanohardness of developed hybrid nanocomposites. Addition of 1 wt% nano Gr as reinforcement in Mg–WC has enhanced both nanohardness and elastic modulus of composites, while further addition include detrimental effects. Corrosion tests are performed with the help of electrochemical impedance spectroscopy and potentiodynamic polarization tests. Corrosion study reveals that incorporation of 1 wt% Gr has improved corrosion resistance but further addition of graphite nanoparticles results in decrease in the corrosion resistance. To ascertain corrosion mechanism, corroded surfaces are characterized which discloses that surface of Mg–2WC–1Gr nanocomposite possess less number of cracks collinear with its least corrosion rate among all hybrid nanocomposites.

Tribological characterisation of magnesium matrix nanocomposites: A review:

Abstract: Magnesium matrix nanocomposites (Mg-MNCs) are high grade materials widely used in aerospace, electronics, biomedical and automotive sectors for high strength to weight ratio, excellent sustainabili...

Abrasive wear behaviour of orange peel (biowaste) particulate reinforced polymer composites

Abstract: The development of lightweight materials has drawn more attention in the last decade in the field of household, construction and automobile sectors in place of conventional materials. New environme...

Influence of Speed and Sliding Distance on the Tribological Performance of Submicron Particulate Reinforced Al-12Si /1.5 Wt% B4C Composite

Abstract: The paper reports wear and friction performance of Al-12Si aluminum alloy reinforced with 1.5 wt% submicron boron carbide (B4C) particles. Composite material is fabricated by ultrasonic stir casting process. Microstructural examination is carried out using optical microscopy and field emission scanning electron microscopy (FESEM). Incorporation and agglomeration-free dispersion of B4C particles is detected in the aluminum matrix. Pin-on-disc tribotester is used to evaluate tribological performance of fabricated composite and base alloy under room temperature dry conditions. Nominal contact pressure of 0.707 MPa is applied against EN31 steel counterface, and sliding speeds are varied between 0.25 and 1.25 m/s. Influence of sliding distance is investigated by varying sliding durations from 10 to 40 min at two fixed load-speed (PV) factors of 10 and 25 Nm/s. Worn pin surfaces and collected wear debris are analyzed using FESEM and energy-dispersive spectroscopy to reveal undergoing wear mechanisms. After initial decrease, wear rate increased almost linearly with speed and became twofold at the top speed. Wear rate transition is seen at 0.5 m/s with sliding distance for the applied pressure. Friction coefficient is not influenced significantly with sliding distance for the fixed PV condition. Adhesion and delamination governed the wear mechanism of base alloy while mechanically mixed layer played key role in the wear performance of composite matrix. Improved wear resistance of aluminum matrix is observed due to incorporation of small amount of B4C particulates making the composite better suited for wear-resistant applications than base alloy.

Co-deposition of W and Mo in electroless Ni–B coating and its effect on the surface morphology, structure, and tribological behavior:

Abstract: The Ni–B binary alloy deposited by autocatalytic chemical deposition technique has tremendous potential of wear/friction reduction and wide industrial usage. A significant improvement in mechanical...

Effect of copper incorporation on phase transformation behavior of electroless nickel–phosphorous coating and its effect on the tribological behavior:

Abstract: The microstructural changes of electroless Ni–P–Cu coating at various heat-treatment conditions are investigated to understand its implications on the tribological behavior of the coating. Coatings...

Fabrication of Aluminium Metal Matrix Nanocomposites: An Overview

Abstract: Aluminium alloy-based composites are in huge demand and under continuous research for obtaining novel, tailor-made property combinations required in high-performance applications. Composites reinforced with uniformly dispersed nanoparticles are observed to display much improved properties as compared to microcomposites and monolithic alloys in several studies published in the last two decades. However, wettability, dispersion, agglomeration and particle–matrix interface debonding are the critical issues related specifically to nanocomposite fabrication making it complex and expensive. Several solid-state and liquid-state routes are developed for manufacturing AMMNCs which are overviewed in this paper highlighting associated prominent features and challenges. Powder metallurgy and liquid metallurgy are the mostly used methods for developing aluminium nanocomposites while their modified versions and hybrid combinations have been used in recent times. Ultrasonic stir casting is found to solve the issue of aluminium-ceramic non-wettability and particle agglomeration to great success.

Nanoindentation, Scratch, and Corrosion Studies of Aluminum Composites Reinforced with Submicron B4C Particles

Abstract: The reported study examines the effect of submicron boron carbide particles on nanohardness, scratch resistance, and corrosion response of Al/B4C composites. Liquid metallurgy involving a combination of mechanical and ultrasonic stirring action is employed to produce composites with varying contents of B4C (0.5, 1, 1.5, and 2 wt%) particles. Fabricated composites are observed under field emission scanning electron microscopy (FESEM) and examined through energy dispersive X-ray (EDX) for particle incorporation and microstructural features. Nanoindentation hardness of alloy increased by 26.59% with just 2.0 wt% B4C and increased with increasing reinforcement. Scratch resistance increased, while wear volume decreased with higher reinforcement content. Scratch hardness is improved by 73% and 29% at 5 N and 20 N applied respective loads. Composites revealed an increase in friction coefficients with increasing applied scratch load. Potentiodynamic polarization and electrochemical impedance spectroscopy tests examined the corrosion properties of composites and base alloy. Surfaces corroded are characterized using the FESEM-EDX tool to understand the corrosion behavior. The incorporation of 0.5 wt% B4C significantly improved the corrosion resistance of Al–Si alloy. But further addition of submicron particles degraded the corrosion response.

Aluminium Hybrid Composites Reinforced with SiC and Fly Ash Particles—Recent Developments

Abstract: The development of aluminium matrix composite (AMC) continues for growing demand of lightweight materials with high strength. Enhancement of the properties of AMCs has been done by changing the types and sizes of reinforcements, wt%, fabrication route and secondary treatment. This chapter provides an overview on the outcome of previous literatures focusing on silicon carbide (ceramic) and fly ash (industrial waste) reinforced AMCs and HAMCs (hybrid). SiC as reinforcement imparts superior mechanical and tribological behaviour in aluminium alloy. Fly ash addition into Al-matrix also has potential in lowering the production cost and density while improving strength. This chapter also highlights the results of nanoparticle size used over conventional micro-particles in the field of AMC development. The influence of processing parameters, mixing percentage of reinforcements, operating conditions and responsible tribological factors are thoroughly discussed. Finally, conclusions have been drawn to recognize the expandable areas of research on AMCs or HAMCs reinforced with SiC and fly ash.

Abrasive wear behavior of Al-TiB2 and Al-TiB2-nano-graphite metal matrix composites:

Abstract: This paper deals with abrasive wear behavior of two different composite materials namely Al-TiB2 and Al-TiB2-nano-graphite At the time of fabrication, ultrasonic vibration is used along with mecha

Understanding Fabrication and Properties of Magnesium Matrix Nanocomposites

Abstract: Magnesium-based metal matrix nanocomposites (MMNCs) are new class materials which can be used widely in aerospace, biomedical, electronics and automobile industries due to their low density, sustainability, good specific strength and better tribological properties. Performance of MMNCs depends on several factors, i.e., composition and combination of reinforcement, processing methods, etc. Present study tries to review available literatures to discuss about the role of those factors on mechanical properties, tribological properties and corrosion behaviors of magnesium-based MMNCs. In this study, liquid metallurgy-based primary processing methods and secondary methods are discussed in details with the help of available literatures. Roles of ultrasonic treatment, cavitation and acoustic streaming on distribution of nanoparticles are discussed in details. Strengthening mechanisms between particle and matrix metal are also presented. Effects of particles like Al2O3, SiC, WC, TiB2, CNT on mechanical, tribological and corrosion behavior are discussed. Mechanical properties (UTS, YS, microhardness, creep behavior) are mainly discussed and available literatures revealed that the presence of nanoparticles normally enhance these properties. Literature on tribological behavior yielded that nanoparticles help to enhance wear and friction behavior of Mg-MMNCs at room and elevated temperatures. Effects of tribological parameters (load, sliding speed, sliding distance) are also discussed. But researchers are split into two groups about corrosion characteristics of magnesium composites. Some researchers reported that corrosion resistance is decreased due to presence of reinforcement while others concluded that corrosion resistance is enhanced due to reinforcing particles.

Finite element simulation of fracture toughness testing of 20MnMoNi55 steel and the effect of loading rate on reference temperature

Abstract: Fracture toughness of ferritic steel in the ductile-to-brittle transition zone is scattered and probabilistic owing to embrittlement. Use of master curve along with the reference temperature (T0) a...

Mg-WC Nanocomposites—Recent Advances and Perspectives

Abstract: Present study summarizes various aspects like fabrication route, microstructural characteristics, mechanical properties, tribological properties of Mg nanocomposites. This study yields that fabrication route plays important role to achieve equiaxed distribution of reinforcement in matrix phase. Mg-MMNCs are developed through different production routes, while main distinction is the matrix state. Among different procedures, liquid metallurgy process is widely accepted due to its simplicity, industrial scalability and cost effectiveness. Effect of incorporation of nanoparticles on microstructure, mechanical properties and tribological properties are revealed by discussing literatures. Special emphasis is given on Mg-WC metal matrix nanocomposites. Effect of WC particles on microhardness, rockwell hardness, ultimate tensile strength and yield strength are also discussed in detail. Finally, wear mechanisms related to different experimental conditions are also mentioned.

Oxidation issues during heat treatment and effect on the tribo-mechanical performance of electroless Ni-P–Cu deposits:

Abstract: The present work attempts to study the issues associated with heat treatment of electroless Ni–P–Cu coatings particularly with respect to oxidation and observe their impact on the hardness (micro- ...

Wear Behavior of Orange Peel Reinforced Epoxy Composite

Abstract: The present paper describes the wear behavior of biowaste (orange peel particulate) reinforced epoxy composites with different filler (0, 10, 20, and 30 wt%) loading. The wear analysis was performed according to ASTM G-99 standard by pin-on-disk apparatus at room temperature by varying the filler loading, applied load, and sliding velocities. The optimum wear resistance was obtained for 20 wt% filler loading. Subsequently, the morphology of selected specimen is analyzed by scanning electron microscope (SEM) to examine the wear analysis such as micro-plowing, fiber matrix debonding, fiber pullout, and micro-cracking.

Tribological behavior of electroless Ni–B coating

Abstract: Electroless Ni–B coating has shown great promise due to its high hardness and wear resistance. Hardness of Ni–B coating further enhances with heat treatment. This increase in hardness on heat treatment is normally due to the change in the coating microstructure and the precipitation Ni–B phases. When observed under powerful microscope, the coating has a cauliflower-like structure which is believed to provide the necessary lubricity for it to display low friction characteristics with the mating object. The tribological phenomena, viz., friction, wear, and corrosion are strongly influenced by the coating composition, that is, presence of nickel, boron, and any other element. In this chapter, the tribological characteristics, viz., roughness, friction, wear, hardness, and corrosion of electroless Ni–B coating are presented. The dependency of these characteristics on the electroless bath ingredients as well as the process parameters is discussed in detail. Besides, the impact of the tribological testing parameters on friction and wear performance of the coating is also deliberated. Finally the results of optimization of coating process parameters and tribological testing parameters to obtain enhanced tribological performance from the coating are presented. This chapter would thus enable the reader to perceive electroless Ni–B coating as a potential substitute in suitable tribological-based applications.

Design of experiment analysis of elevated temperature wear of Mg-WC nano-composites

Abstract: Current study explores the effect of selected process parameters i.e. wt.% of reinforcement (A), elevated temperature (B) and load (C) on wear characteristics of Mg-WC nanocomposites using Taguchi robust design concept. Ultrasonic treated stir casting is employed to synthesize nanocomposites. Three levels for every factor are taken into consideration and accordingly L27 orthogonal array (OA) is used for minimization of wear rate. Main effect plot is generated to investigate the important parameters and optimality is also predicted from the main effect plot. Optimal condition for minimum wear rate is 2wt.% of WC, 100°C temperature and 20N load (A3B1C1). Interaction plots are generated to scrutinize the interaction outcome between selected parameters. ANOVA study is executed to evaluate significant parameters and their effective handout on output. Current investigation reveals, Wt.% of WC is the most significant factor while temperature and load are moderately significant. Among the interacting parameters, interaction between wt.% of WC & temperature (A×B) has moderate significance. Wt.% of WC (A) has 43.135% contribution while temperature (B), load (C) and interaction between wt.% of WC & temperature (A×B) have 26.623%, 19.037% and 5.639% contribution respectively. Residual plots for wear rate are discussed and confirmation test finally helps to validate present experimental model. S/N ratio is improved by 4.411 dB (48.60%) than the initial condition.

Flattening analysis of plastically graded cylindrical contact under plane stress condition

Abstract: The present work deals with finite element based flattening analysis of a functionally graded cylindrical contact against a rigid flat surface under plane stress condition. The yield strength of the semi-cylinder is varied radially according to an exponential function. The contact between the semi-cylinder and the rigid flat is considered to be perfect-slip type in nature. To reduce the computational time, a 2D quarter circle is used to model the cylinder and rigid flat surface is modelled using a straight line. The effect of the gradation parameter on contact behaviours e.g. contact area, contact force, contact pressure etc. of the semi-cylinder are presented and discussed.

Static and Dynamic Analysis of Deformable Fractal Surface in Contact With Rigid Flat

Abstract: The chapter consists of static and dynamic analyses of a fractal rough surface in contact with a rigid flat. The fractal surface is constructed using modified Weierstrass-Mandelbrot function. A rigid flat surface touches the topmost point of the rough surface, which moves towards the rough surface and deforms it. Different contact parameters (e.g., contact force, contact area, contact stress, etc. for varying fractal and material properties are obtained through finite element based static analysis. A parameter denoting the degree of nonlinearity of the contact system is extracted from the force-displacement plot of the surface. This parameter is utilized to explain the dynamic behaviour of the fractal surface which vibrates under the influence of the externally excited rigid flat surface. The dynamic analysis of the contact system is carried out by modelling the contact interface as a single degree of freedom (SDOF) spring-mass-damper system. The dynamic behavior of the system is investigated in terms of frequency response curves, time-displacement plots, and phase plots.

Friction Stir Welding

Abstract: Friction stir welding (FSW) is a solid-state joining process which is a relatively newer technique but has found multiple utility in various industries across the world. By employing FSW, several issues that conventional fusion welding poses, viz. distortion, low efficiency, greater heat-affected zone (HAZ), etc., can be avoided. FSW in fact for some metals gives joint efficiencies near about 100%. FSW has been highly suitable for welding metals, viz. aluminum and magnesium, which have been previously found to be highly challenging to be welded by conventional welding techniques. For this reason, FSW has been embraced by aerospace and marine industries which require welding of large aluminum panels. Joining of dissimilar metals is one of the interesting aspects that FSW is found to handle quite easily as joining occurs much below the actual melting temperature of the metals. Research is also underway for welding metals having high melting points (steel and titanium-based alloys) using FSW in an efficient manner. FSW however involves higher setup costs and thus still out of the reach of many small-scale industries which refrain from higher initial investment. Thus, cost-effective solutions to tackle this issue are continuously explored by engineers and researchers. With a concerted effort, it is likely that the true potential of FSW technique would unfold, and it’s benefits reaped by industries worldwide.

Effect of microstructural constituents and morphological characteristics on low cycle fatigue behaviour of inter-critically annealed 20MnMoNi55 steel

Abstract: The effect of varying microstructural parameters on the cyclic behaviour of dual-phase steels was studied on the basis of experimental and micromechanical finite-element simulated results. The init...

Erosive wear behavior of bio-waste particulate-reinforced epoxy composites for low cost applications

Abstract: Polymer based substances such as epoxy or poly-epoxide has tremendous role in industrial applications such as surface coatings, potting, laminated circuit boards due to its versatile nature. Synthetic fibers are used in polymer composites as reinforcement to increase its mechanical and tribological properties. However, natural fibers/particulates are more preferable over synthetic fibers due to their environment friendliness, high abundance, viable and cost effective. Due to easy accessibility and manufacturing, worldwide researchers have been tempted to develop biofiber-based composite material and study their ability in tribological applications. In this research paper, the erosive behaviors of reinforced epoxy composite with different weight percentage of bio waste (orange peel) were studied. The erosive wear behavior of fabricated composites was evaluated at different impingement/impact angles (i.e., 30°, 60°, 45° and 90°) and impact velocities (48, 70 and 82 m/s) with constant feed rate at 5 gm/min. The solid particle erosion was carried out taking silica sand as erodent and the average size of erodent is 150–250 µm. The impact velocity and impact angle have a tremendous effect on erosive wear. SEM study of eroded surfaces also carried out to inspect the worn surface morphology.

High Temperature Tribology of Surface Coatings

Abstract: Surface coatings are widely used as surface modification technique to improve the properties of the base material without causing any microstructural changes in it. They may be applied to improve tribological behavior of a substrate, improve magnetic properties, solderability, electrical properties or simply to improve its surface finish. Their typical applications include bearings and seals, cylinder liners, piston rings, IC engines, compressors, metal working tools, etc. Since surface coatings find wide industrial usage, there is a need to study the various coating techniques along with their research progress. Moreover, nowadays, surface coatings are being considered as candidates for high temperature applications. Therefore, an effort has been made in this chapter to review the different surface coating techniques along with their research progress. The present chapter discusses several coating deposition techniques particularly in reference with their high temperature applicability and the different wear mechanisms observed.

Influence of Alumina Particles on Tribology of Autocatalytic Ni-P Coatings at High Temperature

Abstract: The present work considers the effects of incorporation of hard Al2O3 particles on the structure, microhardness, and tribological behavior of electroless Ni-P coatings at room temperature and elevated temperature. Ni-P (9% P) coating shows a typical amorphous structure that changes to a mixture of nanocrystalline and amorphous structure due to the addition of alumina particles. The incorporation of Al2O3 particles is found to enhance the overall hardness and wear resistance of the Ni-P coating. Exposure to high temperature during tribological tests acts as brief heat treatment, initiating microstructural changes in the coating which further increases the hardness of the deposit. The scanning electron micrograph of the worn surface of the coating reveals both abrasive and adhesive wear phenomena governing the wear mechanism at elevated temperature. The development of the oxide layer is another important characteristic of the coatings examined under high temperatures (around 500°C).