Proceedings of the Institution of Mechanical Engineers, Part L: Journal of Materials: Design and Applications
The present study investigates buckling characteristics of cut-out borne stiffened hyperbolic par... more The present study investigates buckling characteristics of cut-out borne stiffened hyperbolic paraboloid shell panel made of laminated composites using finite element analysis to evaluate the governing differential equations of global buckling of the structure. The finite element code is validated by solving benchmark problems from literature. Different parametric variations are studied to find the optimum panel buckling load. Laminations, boundary conditions, depth of stiffener and arrangement of stiffeners are found to influence the panel buckling load. Effect of different parameters like cut-out size, shell width to thickness ratio, degree of orthotropy and fiber orientation angle of the composite layers on buckling load are also studied. Parametric and comparative studies are conducted to analyze the buckling strength of composite hyperbolic paraboloid shell panel with cut-out.
This paper presents an experimental study of multiple roughness characteristics of Ni-P-W coating... more This paper presents an experimental study of multiple roughness characteristics of Ni-P-W coatings on a mild steel substrate. The different roughness parameters considered are centre line average roughness (Ra), root mean square roughness (Rq), skewness (Rsk), kurtosis (Rku) and mean line peak spacing (Rsm). The aim of the present study is to optimize the coating process parameters based on Taguchi method and Grey relational analysis in order to obtain the particular bath composition which may be used to deposit Ni-P-W coatings with optimum roughness characteristics. Experiments are carried out based on the L27 Taguchi orthogonal design using the combination of three process parameters, namely, concentration of tungsten ion, concentration of reducing agent and concentration of nickel source. It is observed that concentration of tungsten ion has the most significant influence in controlling roughness characteristics of Ni-P-W coating. The surface morphology, composition and phase str...
Surface roughness plays an important role in product quality and manufacturing process planning. ... more Surface roughness plays an important role in product quality and manufacturing process planning. Surface topography is generally characterized by statistical parameters such as centerline average (Ra), root mean square average (Rq), mean line peak spacing (Rsm) etc. Since surface topography is non-stationary and multi-scaled, these parameters are not sufficient to describe the characteristics of the surface. Fractal dimension, on the other hand, describes surface roughness invariant with length scale and fractals can be extremely useful when applied to tribology. Obtaining fractal descriptions of engineering surfaces requires surface topography information to be measured, digitized and processed. The present work describes the evaluation of the fractal dimensions of the surface profiles generated by grinding with different machining conditions such as work-piece speed, longitudinal feed and radial in-feed. The measured roughness parameters and fractal dimension are analyzed using AN...
1. INTRODUCTION Electroless NiP (EN) coating is an autocatalytic deposition of a NiP alloy from a... more 1. INTRODUCTION Electroless NiP (EN) coating is an autocatalytic deposition of a NiP alloy from an aqueous solution unto a substrate without the application of electric current. The electroless bath typically comprises an aqueous solution of metal ions, complexing agents, reducing agents and stabilizers, operating in a specific metal ion concentration, temperature and pH ranges. The deposition rate, properties of coated components and the structural behavior of deposits mainly depend upon the plating bath constituents/conditions such as the type and concentrations of the reducing agent, stabilizer, used pH and the temperature of the bath etc. [1]. Eletroless deposition process therefore differs from the conventional electroplating processes that depend on an external source of direct current in order to reduce nickel ions in the electrolyte to nickel metal on the substrate. EN coatings have got wide range of industrial applications because of their excellent mechanical, electrical, ...
Electroless nickel coating is an autocatalytic coating whose behavior is very much dependent on t... more Electroless nickel coating is an autocatalytic coating whose behavior is very much dependent on the composition of electroless bath. The present paper studies the synthesis of electroless Ni-P (nickel-phosphorous) coatings on mild steel substrate and optimization of the coating process parameters for minimum friction and wear in alkaline (NaOH) solution using Taguchi based grey relation analysis. The study is carried out using different combinations of four coating process parameters, namely, concentration of nickel source (A), concentration of reducing agent (B), deposition temperature (C) and annealing temperature (D) with three level each (1, 2 and 3). The wear and friction tests are conducted with a pin-on-disk tribometer. Taguchi based grey relational analysis is employed for the optimization of this multiple response problem using an L27 orthogonal array. The optimal combination of parameters is found as A3B3C1D2. ANOVA is performed to find out the significance of the coating ...
This paper presents a desirability function approach in order to find out an optimal combination ... more This paper presents a desirability function approach in order to find out an optimal combination of machining parameters for multiple performance characteristics of the surface roughness parameters in CNC turning operation on mild steel. In the present study, experiments have been conducted using depth of cut, spindle speed and feed rate as cutting parameters for evaluating the roughness parameters such as centre line average (Ra), root mean square (Rq) and mean line peak spacing (Rsm). An orthogonal array (L9) is generated using the Taguchi design to carry out the experiments on AISI 1040 mild steel bar. The individual desirability values of each roughness parameters have been calculated and accumulate to calculate the overall desirability of the surface roughness in turning operation. The signal-to-noise ratio is employed to investigate the optimal combination of cutting parameters to yield maximum overall desirability. After the optimal level of cutting parameters has been find o...
Magnesium matrix nanocomposites (Mg-MNCs) are high grade materials widely used in aerospace, elec... more 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 sustainability and superior mechanical and tribological characteristics. Basic properties of Mg-MNCs rely on type and amount of reinforcement and fabrication process. Current study reviews existing literatures to explore contribution of different parameters on tribological properties of Mg-MNCs. Effects of particle size and amount of different reinforcements like SiC, WC, Al2O3, TiB2, CNT, graphene nano platelets (GNP), graphite on tribological behaviour are discussed. Incorporation of nanoparticles generally enhances properties. Role of different fabrication processes like stir casting (SC), ultrasonic treatment casting (UST), disintegrated melt deposition (DMD), friction stir processing (FSP) on wear and friction behaviour of Mg-MNCs is also reviewed. Contributions of different tribological process ...
International Journal of Surface Science and Engineering
In the present work, a normally loaded contact between a radially functionally graded hemisphere ... more In the present work, a normally loaded contact between a radially functionally graded hemisphere and a rigid flat is analysed in perfect slip condition for different values of gradient/inhomogeneity parameter. The analysis was performed with an axisymmetric model in commercial finite element software ANSYS 18.2. The Young's modulus, yield strength and tangent modulus (for bilinear isotropic hardening) are varied according to an exponential function. The effect of the inhomogeneity parameter on different contact behaviours, e.g., contact area, contact pressure, contact stresses, etc., of the hemisphere are obtained. Stress and deformation behaviour of the contact interface as well as of the entire hemisphere has been analysed. It is observed that for negative inhomogeneity parameter, while being deformed by the rigid flat, the summit of the hemisphere loses contact with flat and sinks in to have a concave shape at the top of the hemisphere. This phenomenon has not been reported in established literature yet.
Aluminum (Al)-based composites are on increasing usage in sectors like ground transportation, aer... more Aluminum (Al)-based composites are on increasing usage in sectors like ground transportation, aerospace, sports, and infrastructure because of the improved properties such as high strength to weight ratio, corrosion, fatigue, and wear resistance. Several applications involving dynamic contact stresses require excellent wear and frictional performance for improved life. Nanocomposites are found to perform exceedingly better than microcomposites and alloys in several lab scale tribological investigations carried out so far in the last decade. In this article, an attempt is made to review those published reports about dry sliding tribological behavior of particulate-reinforced Al nanocomposites. Wear and friction being system properties are found to get influenced by intrinsic factors such as reinforcement, fabrication method, microstructure; extrinsic parameters like load, speed, contact conditions and the system generated in situ tribolayer all being interrelated.
This work examines the effects of WC nanoparticles on nanohardness, elastic modulus and scratch-i... more This work examines the effects of WC nanoparticles on nanohardness, elastic modulus and scratch-induced wear behavior of Mg-based metal matrix nanocomposites. Ultrasonic vibrator-equipped stir casting furnace is used to fabricate Mg–WC nanocomposites. Scanning electron microscopy (SEM), energy-dispersive X-ray analysis (EDAX) and X-ray diffraction (XRD) are employed to conduct the characterizations of base alloy and Mg–WC nanocomposites. Vickers microhardness tester is used to obtain the microhardness values of the fabricated materials. Nanoindentation tests are performed to find the effect of wt.% of WC on the mechanical properties, i.e., nanohardness and elastic modulus. Nanohardness and elastic modulus present nearly 122% and 169.37% increments, respectively, compared to the base alloy when only 2[Formula: see text]wt.% of WC is present as reinforcement. Scratch tests are performed to find the effects of wt.% of WC and applied load on the scratch-induced wear and coefficient of f...
Proceedings of the Institution of Mechanical Engineers, Part L: Journal of Materials: Design and Applications
The present study investigates buckling characteristics of cut-out borne stiffened hyperbolic par... more The present study investigates buckling characteristics of cut-out borne stiffened hyperbolic paraboloid shell panel made of laminated composites using finite element analysis to evaluate the governing differential equations of global buckling of the structure. The finite element code is validated by solving benchmark problems from literature. Different parametric variations are studied to find the optimum panel buckling load. Laminations, boundary conditions, depth of stiffener and arrangement of stiffeners are found to influence the panel buckling load. Effect of different parameters like cut-out size, shell width to thickness ratio, degree of orthotropy and fiber orientation angle of the composite layers on buckling load are also studied. Parametric and comparative studies are conducted to analyze the buckling strength of composite hyperbolic paraboloid shell panel with cut-out.
This paper presents an experimental study of multiple roughness characteristics of Ni-P-W coating... more This paper presents an experimental study of multiple roughness characteristics of Ni-P-W coatings on a mild steel substrate. The different roughness parameters considered are centre line average roughness (Ra), root mean square roughness (Rq), skewness (Rsk), kurtosis (Rku) and mean line peak spacing (Rsm). The aim of the present study is to optimize the coating process parameters based on Taguchi method and Grey relational analysis in order to obtain the particular bath composition which may be used to deposit Ni-P-W coatings with optimum roughness characteristics. Experiments are carried out based on the L27 Taguchi orthogonal design using the combination of three process parameters, namely, concentration of tungsten ion, concentration of reducing agent and concentration of nickel source. It is observed that concentration of tungsten ion has the most significant influence in controlling roughness characteristics of Ni-P-W coating. The surface morphology, composition and phase str...
Surface roughness plays an important role in product quality and manufacturing process planning. ... more Surface roughness plays an important role in product quality and manufacturing process planning. Surface topography is generally characterized by statistical parameters such as centerline average (Ra), root mean square average (Rq), mean line peak spacing (Rsm) etc. Since surface topography is non-stationary and multi-scaled, these parameters are not sufficient to describe the characteristics of the surface. Fractal dimension, on the other hand, describes surface roughness invariant with length scale and fractals can be extremely useful when applied to tribology. Obtaining fractal descriptions of engineering surfaces requires surface topography information to be measured, digitized and processed. The present work describes the evaluation of the fractal dimensions of the surface profiles generated by grinding with different machining conditions such as work-piece speed, longitudinal feed and radial in-feed. The measured roughness parameters and fractal dimension are analyzed using AN...
1. INTRODUCTION Electroless NiP (EN) coating is an autocatalytic deposition of a NiP alloy from a... more 1. INTRODUCTION Electroless NiP (EN) coating is an autocatalytic deposition of a NiP alloy from an aqueous solution unto a substrate without the application of electric current. The electroless bath typically comprises an aqueous solution of metal ions, complexing agents, reducing agents and stabilizers, operating in a specific metal ion concentration, temperature and pH ranges. The deposition rate, properties of coated components and the structural behavior of deposits mainly depend upon the plating bath constituents/conditions such as the type and concentrations of the reducing agent, stabilizer, used pH and the temperature of the bath etc. [1]. Eletroless deposition process therefore differs from the conventional electroplating processes that depend on an external source of direct current in order to reduce nickel ions in the electrolyte to nickel metal on the substrate. EN coatings have got wide range of industrial applications because of their excellent mechanical, electrical, ...
Electroless nickel coating is an autocatalytic coating whose behavior is very much dependent on t... more Electroless nickel coating is an autocatalytic coating whose behavior is very much dependent on the composition of electroless bath. The present paper studies the synthesis of electroless Ni-P (nickel-phosphorous) coatings on mild steel substrate and optimization of the coating process parameters for minimum friction and wear in alkaline (NaOH) solution using Taguchi based grey relation analysis. The study is carried out using different combinations of four coating process parameters, namely, concentration of nickel source (A), concentration of reducing agent (B), deposition temperature (C) and annealing temperature (D) with three level each (1, 2 and 3). The wear and friction tests are conducted with a pin-on-disk tribometer. Taguchi based grey relational analysis is employed for the optimization of this multiple response problem using an L27 orthogonal array. The optimal combination of parameters is found as A3B3C1D2. ANOVA is performed to find out the significance of the coating ...
This paper presents a desirability function approach in order to find out an optimal combination ... more This paper presents a desirability function approach in order to find out an optimal combination of machining parameters for multiple performance characteristics of the surface roughness parameters in CNC turning operation on mild steel. In the present study, experiments have been conducted using depth of cut, spindle speed and feed rate as cutting parameters for evaluating the roughness parameters such as centre line average (Ra), root mean square (Rq) and mean line peak spacing (Rsm). An orthogonal array (L9) is generated using the Taguchi design to carry out the experiments on AISI 1040 mild steel bar. The individual desirability values of each roughness parameters have been calculated and accumulate to calculate the overall desirability of the surface roughness in turning operation. The signal-to-noise ratio is employed to investigate the optimal combination of cutting parameters to yield maximum overall desirability. After the optimal level of cutting parameters has been find o...
Magnesium matrix nanocomposites (Mg-MNCs) are high grade materials widely used in aerospace, elec... more 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 sustainability and superior mechanical and tribological characteristics. Basic properties of Mg-MNCs rely on type and amount of reinforcement and fabrication process. Current study reviews existing literatures to explore contribution of different parameters on tribological properties of Mg-MNCs. Effects of particle size and amount of different reinforcements like SiC, WC, Al2O3, TiB2, CNT, graphene nano platelets (GNP), graphite on tribological behaviour are discussed. Incorporation of nanoparticles generally enhances properties. Role of different fabrication processes like stir casting (SC), ultrasonic treatment casting (UST), disintegrated melt deposition (DMD), friction stir processing (FSP) on wear and friction behaviour of Mg-MNCs is also reviewed. Contributions of different tribological process ...
International Journal of Surface Science and Engineering
In the present work, a normally loaded contact between a radially functionally graded hemisphere ... more In the present work, a normally loaded contact between a radially functionally graded hemisphere and a rigid flat is analysed in perfect slip condition for different values of gradient/inhomogeneity parameter. The analysis was performed with an axisymmetric model in commercial finite element software ANSYS 18.2. The Young's modulus, yield strength and tangent modulus (for bilinear isotropic hardening) are varied according to an exponential function. The effect of the inhomogeneity parameter on different contact behaviours, e.g., contact area, contact pressure, contact stresses, etc., of the hemisphere are obtained. Stress and deformation behaviour of the contact interface as well as of the entire hemisphere has been analysed. It is observed that for negative inhomogeneity parameter, while being deformed by the rigid flat, the summit of the hemisphere loses contact with flat and sinks in to have a concave shape at the top of the hemisphere. This phenomenon has not been reported in established literature yet.
Aluminum (Al)-based composites are on increasing usage in sectors like ground transportation, aer... more Aluminum (Al)-based composites are on increasing usage in sectors like ground transportation, aerospace, sports, and infrastructure because of the improved properties such as high strength to weight ratio, corrosion, fatigue, and wear resistance. Several applications involving dynamic contact stresses require excellent wear and frictional performance for improved life. Nanocomposites are found to perform exceedingly better than microcomposites and alloys in several lab scale tribological investigations carried out so far in the last decade. In this article, an attempt is made to review those published reports about dry sliding tribological behavior of particulate-reinforced Al nanocomposites. Wear and friction being system properties are found to get influenced by intrinsic factors such as reinforcement, fabrication method, microstructure; extrinsic parameters like load, speed, contact conditions and the system generated in situ tribolayer all being interrelated.
This work examines the effects of WC nanoparticles on nanohardness, elastic modulus and scratch-i... more This work examines the effects of WC nanoparticles on nanohardness, elastic modulus and scratch-induced wear behavior of Mg-based metal matrix nanocomposites. Ultrasonic vibrator-equipped stir casting furnace is used to fabricate Mg–WC nanocomposites. Scanning electron microscopy (SEM), energy-dispersive X-ray analysis (EDAX) and X-ray diffraction (XRD) are employed to conduct the characterizations of base alloy and Mg–WC nanocomposites. Vickers microhardness tester is used to obtain the microhardness values of the fabricated materials. Nanoindentation tests are performed to find the effect of wt.% of WC on the mechanical properties, i.e., nanohardness and elastic modulus. Nanohardness and elastic modulus present nearly 122% and 169.37% increments, respectively, compared to the base alloy when only 2[Formula: see text]wt.% of WC is present as reinforcement. Scratch tests are performed to find the effects of wt.% of WC and applied load on the scratch-induced wear and coefficient of f...
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