Showing papers by "Prasanta Sahoo published in 2019"
TL;DR: In this paper, the effect of WC nano-particles on tribological behavior of magnesium based nanocomposites for varying wt% of WC (0.5, 1, 1.5 and 2) was investigated.
48 citations
TL;DR: In this article, the effect of operating temperature on the tribological behavior of electroless Ni-P-W coating developed over mild steel is evaluated. And the results reveal that Ni-p-W coatings display a stable friction and wear behaviour even when subjected to elevated working temperature.
33 citations
TL;DR: In this article, the effects of WC nano-particles amount and surface roughness on corrosion behavior of magnesium metal matrix nano-composites in 3.5% NaCl solution are examined with the help of electrochemical test.
25 citations
TL;DR: Scanning electron micrography of the machined surface reveals that the combined ANN-GA method can significantly improve the surface texture produced from WEDM by reducing the formation of re-solidified globules.
Abstract: To achieve enhanced surface characteristics in wire electrical discharge machining (WEDM), the present work reports the use of an artificial neural network (ANN) combined with a genetic algorithm (GA) for the correlation and optimization of WEDM process parameters. The parameters considered are the discharge current, voltage, pulse-on time, and pulse-off time, while the response is fractal dimension. The usefulness of fractal dimension to characterize a machined surface lies in the fact that it is independent of the resolution of the instrument or length scales. Experiments were carried out based on a rotatable central composite design. A feed-forward ANN architecture trained using the Levenberg-Marquardt (L-M) back-propagation algorithm has been used to model the complex relationship between WEDM process parameters and fractal dimension. After several trials, 4-3-3-1 neural network architecture has been found to predict the fractal dimension with reasonable accuracy, having an overall R-value of 0.97. Furthermore, the genetic algorithm (GA) has been used to predict the optimal combination of machining parameters to achieve a higher fractal dimension. The predicted optimal condition is seen to be in close agreement with experimental results. Scanning electron micrography of the machined surface reveals that the combined ANN-GA method can significantly improve the surface texture produced from WEDM by reducing the formation of re-solidified globules.
24 citations
01 Jan 2019
TL;DR: In this paper, the authors explored the tribological implications of various materials employed in biomedical applications, namely friction, wear, and corrosion, in order to further enhance their durability and decrease the frequency of surgical replacement and a more normal life for the patient.
Abstract: With recent advancements in medical science, there have been improvements in the quality of human life. The discoveries in the field of materials has positively impacted the development of prosthetics and implants, which are becoming more biocompatible as well as durable. To gain knowledge of the tribological characteristics of these materials, namely friction, wear, and corrosion, is significant in order to further enhance their durability, leading to a decrease in the frequency of surgical replacement and a more normal life for the patient. Hence, this chapter explores the tribological implications of various materials employed in biomedical applications.
23 citations
TL;DR: In this article, a study of 1´g/l alumina reinforced electroless Ni-B coatings on a low carbon steel substrate was carried out, where the nano particles were ultra-sonicated before being introduced into the coating bath.
21 citations
31 May 2019
17 citations
TL;DR: In this article, the wear and coefficient of friction of Ni-B coatings are significantly affected by the load, speed and test temperature which in turn control the in-situ oxide formation and microstructural changes during the wear process.
Abstract: Electroless Ni-B coatings are deposited on AISI 1040 steel specimens and heat treated at 350 ∘C for 1 h to improve their properties. Coating characterization is done using energy dispersive X-ray analysis, scanning electron microscope and X-ray diffraction techniques. The as-deposited coatings are amorphous and become crystalline on heat treatment. Microhardness of the coatings improves significantly on heat treatment due to the precipitation of boride phases. The tribological behavior of the heat treated coatings is observed on a pin-on-disk tribological test setup by varying the applied normal load, speed of the counterface material and the test temperature. The wear and coefficient of friction of the coatings are significantly affected by the load, speed and test temperature which in turn control the in-situ oxide formation and microstructural changes during the wear process. This is further confirmed by examining the worn specimens using scanning electron microscope and energy dispersive X-ray analysis.
16 citations
TL;DR: In a quest to achieve enhanced thermal stability of Ni-B coatings, Mo is used in this article to achieve higher thermal stability in comparison with the binary alloy variants of the Ni-C coatings.
Abstract: Electroless nickel coatings containing Mo possess higher thermal stability in comparison with the binary alloy variants. In a quest to achieve enhanced thermal stability of Ni–B coatings, Mo is inc...
12 citations
TL;DR: In this paper, the effects of WC nanoparticles on nanohardness, elastic modulus and scratch-induced wear behavior of Mg-based metal matrix nanocomposites were examined.
Abstract: 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 cast...
10 citations
TL;DR: In this paper, a phenomenological constitutive model is developed to describe the flow behaviour of 20MnMoNi55 low carbon reactor pressure vessel (RPV) steel at sub-zero temperature under different strain rates.
29 Nov 2019
TL;DR: In this paper, Electroless Nickel boron (Ni-B) coatings were deposited over mild steel substrates to study the effect of borohydride concentration on tribological behaviour and mechanical properties.
Abstract: Electroless Nickel boron (Ni-B) coatings were deposited over mild steel substrates to study the effect of borohydride concentration on tribological behaviour and mechanical properties. Three different types of coating bath solutions were used to deposit coatings. The as-deposited coatings were characterised based on surface morphology, composition and phase structure using scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS) and x-ray diffraction (XRD), respectively. Friction and wear behaviour of the as-deposited coatings were evaluated by pin-on-disc tribo-tester. Coefficient of friction of the coatings decreases with the increase in borohydride concentration. Surface hardness, elastic modulus and scratch resistance behaviour of the coatings were evaluated using the data obtained by nano-indentation techniques. It is seen that the surface hardness and elastic modulus of the as-deposited coatings increase with the increase in borohydride concentrations. Electrochemical impedance spectroscopy (EIS) and potentiodynamic polarisation tests were conducted to analyse corrosion behaviour of the coatings against a corrosive environment of 3.5% NaCl solution. The corrosion test results displayed an increasing trend of corrosion resistance as the borohydride concentration increases in the coating bath solution.
TL;DR: In this article, the friction behavior of magnesium nano-composites reinforced with WC nano-particles in a pin-on-doscopes tribotester is investigated.
31 Jul 2019
TL;DR: In this paper, the effects of temperature on the friction and wear behavior of Ni-P-B alloy coatings have been investigated, and the results show that Ni-p-B coatings sustain the elevated temperatures with minimal effect on friction performance.
Abstract: Ni–P–B coatings are produced directly on surface of carbon steel (AISI 1040) using electroless plating technique. The effects of temperature on the friction and wear behavior of Ni–P–B alloy coatings have been investigated. Tribological tests are conducted at four temperatures (30, 100, 300 and 500 °C) under constant load and sliding speed in a pin-on-disk apparatus. Results show that Ni–P–B coatings sustain the elevated temperatures with minimal effect on friction and wear performances. Ni–P–B coating is found to exhibit the maximum hardness among the binary Ni–P and Ni–B coatings with as-deposited hardness reaching around 700HV. Heat treatment increases the hardness as well as wear resistance by precipitation of boride and phosphide phases of nickel. Room temperature test shows mostly adhesive wear pattern but finally, it leads to a mixture of abrasive–adhesive wear mechanism. Friction and wear of Ni–P–B is overall governed by the formation of oxidative layer, mechanically mixed layer with iron (from ferrous counter face), wear mechanism, phase transformation and changes in microstructure during elevated wear test. Phase transformation and corresponding micro-structural changes occurring during elevated test duration help in providing better wear resistance to the coating.
03 Apr 2019
TL;DR: In this article, a dynamic analysis of a hemispherical and cylindrical contact, material properties of which are graded elastically and plastically along the radius, is presented.
Abstract: A dynamic analysis of a hemispherical and cylindrical contact, material properties of which are graded elastically and plastically along the radius, is presented. The static force–displacement beha...
TL;DR: In this article, the effect of different heat treatment temperature on mechanical (hardness) and tribological behavior (friction and wear) of EN-P and Ni-P-Cu coatings was investigated.
TL;DR: In this paper, Ni-B-W-Mo coatings were applied on AISI 1040 steel by the electroless method and they were heat-treated at 300, 350, 400, 450 and 500 °C for 1 hour.
Abstract: Quaternary Ni-B-W-Mo coatings were deposited on AISI 1040 steel by the electroless method. Some of the specimens were heat-treated at 300, 350, 400, 450 and 500 °C, for 1 hour. The deposited coatings contained a high weight percentage of W, and a low B content was detected by energy dispersive X-ray analysis. The coatings in as-deposited state were amorphous, and heat treatment resulted in crystallization with the precipitation of borides. W and Mo were present in the coatings, mainly in a solid solution form. The surface morphology study revealed densely nodulated structures, which are pertinent for sodium borohydride reduced electroless nickel coatings. Electrochemical impedance spectroscopy studies were conducted to determine the corrosion resistance of the as-deposited and heat-treated coatings in a 3.5% NaCl electrolyte. The corroded surfaces were observed under scanning electron microscope, to study the corrosion mechanism.
TL;DR: In this paper, the effect of incorporation of varying weight percentages (0.5, 1, 1.5 and 2) of boron carbide nanoparticles in aluminum-silicon alloy LM6 is investigated.
TL;DR: In this paper, the authors dealt with the abrasive wear behavior of Al-TiB2 metal matrix composites and obtained wear results according to the design of experiments based on Taguchi L27 orthogonal array.
TL;DR: In this paper, the effect of process parameters on wear behavior of magnesium nano-composites reinforced with WC nano-particles with the help of Taguchi methodology is examined.
TL;DR: In this article, the corrosion behavior of Al-TiB2 metal matrix composites in 3.5% NaCl solution was evaluated using scanning electron microscopy (SEM) images.
Abstract: The present study evaluates the corrosion behavior of Al–TiB2 metal matrix composites in 3.5% NaCl solution. Composites are fabricated using stir-casting with varying wt.% of TiB2. Composite surfaces are characterized using scanning electron microscopy (SEM) images. Micro-hardness values of composites are obtained using a Vicker's micro-hardness tester. The hardness of the base matrix is enhanced due to the incorporation of hard TiB2 phase. Corrosion characteristics of composites are investigated using potentiodynamic polarization and electrochemical impedance spectroscopy measurements. Corrosion resistance of composites is estimated from the parameters such as corrosion potential, corrosion current, linear polarization resistance etc. Corrosion resistance of the base alloy improves due to incorporation of TiB2 but only up to a certain amount of TiB2 phase in the matrix. The composite with 1 wt.% TiB2 shows the highest corrosion resistance. Corroded surfaces are studied using SEM images that reve...
TL;DR: In this paper, the authors deal with the abrasive friction behavior of Al-TiB 2 metal matrix composites and calculate coefficient of friction values according to the design of experiments based on Taguchi L27 orthogonal array.
01 Jan 2019
TL;DR: In this article, a major revamp of the higher education policy is needed for improving the quality of engineering education, which would give rise to strengthened manufacturing sector, which will expand the country's economy and push it toward the path of progress.
Abstract: Technical education in India contributes a major share to the overall education system and plays a vital role in the social and economic development of our nation. However, due to several factors, the engineering education system of the country is experiencing a downfall. Poor infrastructure, lack of qualified faculties, insufficient financial assistance, etc., have given rise to engineering graduates many of whom are found not suitable for employment. In this scenario, the manufacturing sector of the country is suffering as it is not getting quality workforce. Some positive initiatives toward strengthening the manufacturing sector have been taken by the Government of India. But tackling the issue at the grass root level has mostly remained ignored. For improving the quality of engineering education, a major revamp of the higher education policy is needed. After all, improved education system would give rise to strengthened manufacturing sector, which will expand the country's economy and push it toward the path of progress.
01 Jul 2019
TL;DR: In this article, the effect of turning process parameters, namely depth of cut and feed rate on the fractal dimension of AISI 1040 steel was examined, and the optimal setting of process parameters has been achieved through the use of Taguchi's quality loss function represented by a signal-to-noise ratio.
Abstract: The present work examines the effect of turning process parameters, namely depth of cut and feed rate on the fractal dimension of AISI 1040 steel. Machined surfaces have been characterized using fractal dimensions. Apart from the aforesaid conventional turning parameters, cutting condition has been also considered as a design variable. Three cutting conditions have been considered, e.g. dry, water lubricated, and commercially available water-soluble emulsion lubricated condition. The depth of cut and feed rate has been also been varied at three levels. Experiments were performed following Taguchi's L9 orthogonal array. The optimal setting of process parameters has been achieved through the use of Taguchi's quality loss function represented by a signal-to-noise ratio. The optimal condition predicted from Taguchi's analysis is a 0.4 mm depth of cut, a 0.07 mm/rev feed rate and a water-based emulsion cutting environment. The results obtained for fractal dimensions has been also compared with the more conventional roughness parameter centre line average roughness which is dependent on instrument resolution.
TL;DR: In this paper, a normally loaded contact between a radially functionally graded hemisphere and a rigid flat is analyzed in perfect slip condition for different values of gradient/inhomogeneity parameter.
Abstract: 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.
01 Dec 2019
01 Nov 2019
01 Jan 2019
TL;DR: A comprehensive overview of the tribological measurements and evaluation methods related to surface roughness and friction/wear characteristics of electroless nickel coatings can be found in this paper, where different tribological measurement techniques employed to evaluate the coatings and their response to the same are summarized.
Abstract: The tribological characteristics of electroless nickel coatings have been in focus since its inception. With the passage of time, electroless nickel coatings have proven to be a promising candidate as tribo-coatings. Electroless nickel coatings have now evolved into a large family of functional coatings due to the flexibility of the process. Depending upon the need and cater into the rising industrial demands, different varieties of electroless nickel coatings have been deposited and evaluated. In fact, simulation of test conditions and test environments as per industrial demands has led to the investigation of the coatings on a variety of test setups. Different tribological measurement techniques employed to evaluate the coatings and the response of the coatings to the same are summarized. The present chapter gives a comprehensive overview of tribological measurements and evaluation methods related to surface roughness and friction/wear characteristics of electroless nickel coatings.