Mukund Sharma - Academia.edu (original) (raw)

Papers by Mukund Sharma

Journal of tribology, Apr 13, 2016

Modeling of dry sliding friction and wear behavior of Ti3Al2.5V alloy sliding against EN31 steel ... more Modeling of dry sliding friction and wear behavior of Ti3Al2.5V alloy sliding against EN31 steel using a multi-tribotester has been presented. Mathematical model equations in the form of natural log transformation for wear rate (WR), average coefficient of friction (μa), and a square root transformation for maximum contact temperature (Tm) considering the effect of tribological variables have been developed and validated by comparing them with the experimental results. The authors claim novelty with regard to modeling and optimization of friction and wear characteristics of Ti-3Al2.5V alloy. The results reveal that the magnitude of wear rate and maximum contact temperature increases with increase in sliding velocity and increasing normal load with few exceptions. Whereas average coefficient of friction first increases with increasing sliding velocity up to 2.51 m/s, and then decreases at highest sliding velocity. The load is found to have strongest influence on both wear rate and average coefficient of friction followed by sliding velocity, whereas sliding velocity has strongest influence on the maximum contact temperature followed by load. The perturbation plot results are also in accordance with the analysis of variance (ANOVA) analysis. The theoretical and experimental results have an average error of 5.06%, 1.78%, and 1.42%, respectively, for wear rate, average coefficient of friction, and maximum contact temperature. Optimization resulted in a maximum desirability of 0.508 at a load of 60 N and a sliding velocity of 1.5 m/s. For these values, the predicted minimum wear rate is 0.0001144 g/m, the coefficient of friction is 0.3181, and the tool-tip temperature is 59.03 °C.

Tribology transactions, Apr 21, 2016

ABSTRACT This article aims to study the friction and wear behavior of Ti3Al2.5V alloy sliding aga... more ABSTRACT This article aims to study the friction and wear behavior of Ti3Al2.5V alloy sliding against EN-31 steel under dry condition using a multi-tribotester. The effect of variation in load and sliding velocity on wear rate, average coefficient of friction, and contact temperature has been studied and analysis of wear debris has been carried out. Scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDS) were employed to study the morphology of the wear tracks and deduce microchemical information at the elemental level of worn samples, respectively. Results reveal that the wear rate of Ti-3Al-2.5V increases with increasing sliding velocity and increasing normal load with few exceptions. The average coefficient of friction decreases as the normal load increases with exceptions at some loads. SEM micrographs of worn samples obtained at different loads and sliding velocities show the formation of wear tracks on the surface due to ploughing and flaking of the matrix. The main mechanism responsible for wear of Ti3Al2.5V alloy sample is rupture of the matrix and abrasion. Wear debris analysis shows irregular-shaped wear particles with very sharp edges that appeared to be plastically deformed at high sliding velocity, whereas the wear debris is very loose and fine at lowest sliding velocity.

Journal of Magnetism and Magnetic Materials, Aug 1, 2023

Journal of Industrial and Engineering Chemistry, Feb 1, 2023

Journal of Industrial and Engineering Chemistry

Journal of Magnetism and Magnetic Materials, 2021

Abstract Magnetorheological (MR) fluids are one of the most valuable smart soft materials for vib... more Abstract Magnetorheological (MR) fluids are one of the most valuable smart soft materials for vibration damper and shock absorber in a wide range of engineering applications because they change their viscoelastic properties when subjected to external magnetic fields. These fluids are prepared by dispersing the soft magnetic micro size particles in the nonmagnetic carrier oils, i.e., mineral oil (MO) and synthetic oil with stabilizing additives. The prominent feature of these fluids is their propensity to the reversible transformation from fluid to semi-solid-state and vice versa within milliseconds under the external magnetic field. The long-time stability and low magnetorheological effect are still considered as one of the most critical problems that need to be solved. There are many methods to resolve this problem, and many researchers are working to improve their stabilization and MR effect. This study reviews the prevalent stabilization techniques, different preparation methods and tribological behaviour of these fluids under an external magnetic field. Additionally, applications of magnetorheological fluid (MRF), rheological models, temperature dependency, current scenarios and future directions are also discussed.

Arabian Journal for Science and Engineering, 2015

For machining operations during the last few decades, there has been major progress in developing... more For machining operations during the last few decades, there has been major progress in developing models for industries. This paper aimed to develop mathematical models using Design Expert 7.1 software to study the effect of cutting parameters on main cutting force, surface roughness and stress. Second objective of this research work was to optimize the machining process by finding the best parameters setting with defined goals for the variables. Results reveal that the value of main cutting force decreases with a decrease in the value of cutting speed and depth of cut. The most significant factors in case of surface roughness and stress are feed rate and depth of cut, respectively. Mathematical models have been developed for main cutting force, surface roughness and stress, and average errors of 3.87, 5.41 and 2.96 % were observed for the corresponding values and analogous trend lines of the plots, respectively. The optimal set of conditions possessing highest desirability value (0.617) and lowest surface roughness (out of eight solutions having the same desirability of 0.617) is as follows: cutting speed-138.29 m/min; feed rate-0.13 mm/rev; depth of cut-0.28 mm (input parameters) and main cutting force-219.273 N; surface roughness-0.439 µm; stress-5128.18 N/mm 2 (responses for input parameters).

Industrial Lubrication and Tribology, 2014

Purpose – In the present study, an attempt has been made to examine friction and wear behaviour o... more Purpose – In the present study, an attempt has been made to examine friction and wear behaviour of Ti-6Al-4V alloy sliding against EN-31 steel under lubricative media of common commercial grade oil (hydrol-68). The paper aims to discuss these issues. Design/methodology/approach – Tribological properties of Ti-6Al-4V under hydrol-68 as lubricative media are measured using multi-tribo tester. Lubricating oil samples at different normal loads have also been analysed with the help of laser net fines (LNF) as per ISO 4406:1999. Experiments have been designed by two level full factorial method. Findings – Experimental results indicate that the wear rate of Ti-6Al-4V alloy decreases as sliding speed increases. But it shows typical transition characteristics as the normal load increases; till 30 N wear rate decreases then it increases from 30 to 50 N. Also for all loads and at every speed, the average wear increases as the sliding distance increases. The average coefficient of friction of t...

The Journal of Men's Studies, 2015

Tribology Online, 2012

Friction and wear are the most commonly encountered industrial problems leading to the replacemen... more Friction and wear are the most commonly encountered industrial problems leading to the replacement of components and assemblies in engineering. There have been great advances in the development of aerospace technology because of the use of titanium alloys. Titanium alloys have wide range of applications for which they have received considerable interest recently because they show an astonishing range of mechanical properties. The present investigation covers the study of dry sliding friction and wear of the Ti6Al4V alloy, which alone covers about 50% of the total world production of titanium alloys. The main objective of this study is to investigate the dry sliding friction and wear behaviour of titanium alloy (Ti-6Al-4V) sliding against EN31 steel. The results show that the wear rate of the Ti6Al4V alloy decreases with increasing sliding velocity and decreasing normal load with few exceptions thus showing typical transition characteristics. The average coefficient of friction decreases as the normal load increases with few exceptions. Also the average coefficient of friction increases as the sliding distance increases for all loads and sliding velocities. The average length of biggest, medium and smallest wear debris was found to be 1.026 µm, 0.711 µm and 0.401 µm respectively.

Arabian Journal for Science and Engineering, 2013

Machining characteristics of titanium alloy grade-5 (Ti–6Al–4V) have been examined at different c... more Machining characteristics of titanium alloy grade-5 (Ti–6Al–4V) have been examined at different cutting speeds, feed rates and approaching angles under dry condition. It has been observed that with the increase in cutting speeds, the magnitude of cutting forces and tool tip temperature increase. If both cutting force and temperature level were considered together, the optimum approaching angle works out to be 45◦ and 90◦ for 49.5 and 76.7m/min, respectively. For 116.9m/min increase of cutting forces at 60◦ approaching angle can be attributed to low-shear angle which is function of the average chip thickness. Positive rake angle produces higher shear angle which leads to the reduction of cutting forces, tool tip temperature and thus help obtaining a better surface finish. Surface roughness measurements obtained prior and subsequent to the machining of titanium alloy (Ti–6Al–4V) were used to characterize the change in roughness caused by variation in machining parameters like cutting speed, feed rate and approaching angle. The average surface roughness is observed to be maximum at 0.11 mm/min and minimum at 0.04 mm/min feed rate for all approaching angles.

Industrial Lubrication and Tribology, 2014

Arabian Journal for Science and Engineering, 2013

Machining characteristics of titanium alloy grade-5 (Ti–6Al–4V) have been examined at different c... more Machining characteristics of titanium alloy grade-5 (Ti–6Al–4V) have been examined at different cutting speeds, feed rates and approaching angles under dry condition. It has been observed that with the increase in cutting speeds, the magnitude of cutting forces and tool tip temperature increase. If both cutting force and temperature level were considered together, the optimum approaching angle works out to be 45◦ and 90◦ for 49.5 and 76.7m/min, respectively. For 116.9m/min increase of cutting forces at 60◦ approaching angle can be attributed to low-shear angle which is function of the average chip thickness. Positive rake angle produces higher shear angle which leads to the reduction of cutting forces, tool tip temperature and thus help obtaining a better surface finish. Surface roughness measurements obtained prior and subsequent to the machining of titanium alloy (Ti–6Al–4V) were used to characterize the change in roughness caused by variation in machining parameters like cutting speed, feed rate and approaching angle. The average surface roughness is observed to be maximum at 0.11 mm/min and minimum at 0.04 mm/min feed rate for all approaching angles.

Journal of tribology, Apr 13, 2016

Modeling of dry sliding friction and wear behavior of Ti3Al2.5V alloy sliding against EN31 steel ... more Modeling of dry sliding friction and wear behavior of Ti3Al2.5V alloy sliding against EN31 steel using a multi-tribotester has been presented. Mathematical model equations in the form of natural log transformation for wear rate (WR), average coefficient of friction (μa), and a square root transformation for maximum contact temperature (Tm) considering the effect of tribological variables have been developed and validated by comparing them with the experimental results. The authors claim novelty with regard to modeling and optimization of friction and wear characteristics of Ti-3Al2.5V alloy. The results reveal that the magnitude of wear rate and maximum contact temperature increases with increase in sliding velocity and increasing normal load with few exceptions. Whereas average coefficient of friction first increases with increasing sliding velocity up to 2.51 m/s, and then decreases at highest sliding velocity. The load is found to have strongest influence on both wear rate and average coefficient of friction followed by sliding velocity, whereas sliding velocity has strongest influence on the maximum contact temperature followed by load. The perturbation plot results are also in accordance with the analysis of variance (ANOVA) analysis. The theoretical and experimental results have an average error of 5.06%, 1.78%, and 1.42%, respectively, for wear rate, average coefficient of friction, and maximum contact temperature. Optimization resulted in a maximum desirability of 0.508 at a load of 60 N and a sliding velocity of 1.5 m/s. For these values, the predicted minimum wear rate is 0.0001144 g/m, the coefficient of friction is 0.3181, and the tool-tip temperature is 59.03 °C.

Tribology transactions, Apr 21, 2016

ABSTRACT This article aims to study the friction and wear behavior of Ti3Al2.5V alloy sliding aga... more ABSTRACT This article aims to study the friction and wear behavior of Ti3Al2.5V alloy sliding against EN-31 steel under dry condition using a multi-tribotester. The effect of variation in load and sliding velocity on wear rate, average coefficient of friction, and contact temperature has been studied and analysis of wear debris has been carried out. Scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDS) were employed to study the morphology of the wear tracks and deduce microchemical information at the elemental level of worn samples, respectively. Results reveal that the wear rate of Ti-3Al-2.5V increases with increasing sliding velocity and increasing normal load with few exceptions. The average coefficient of friction decreases as the normal load increases with exceptions at some loads. SEM micrographs of worn samples obtained at different loads and sliding velocities show the formation of wear tracks on the surface due to ploughing and flaking of the matrix. The main mechanism responsible for wear of Ti3Al2.5V alloy sample is rupture of the matrix and abrasion. Wear debris analysis shows irregular-shaped wear particles with very sharp edges that appeared to be plastically deformed at high sliding velocity, whereas the wear debris is very loose and fine at lowest sliding velocity.

Journal of Magnetism and Magnetic Materials, Aug 1, 2023

Journal of Industrial and Engineering Chemistry, Feb 1, 2023

Journal of Industrial and Engineering Chemistry

Journal of Magnetism and Magnetic Materials, 2021

Abstract Magnetorheological (MR) fluids are one of the most valuable smart soft materials for vib... more Abstract Magnetorheological (MR) fluids are one of the most valuable smart soft materials for vibration damper and shock absorber in a wide range of engineering applications because they change their viscoelastic properties when subjected to external magnetic fields. These fluids are prepared by dispersing the soft magnetic micro size particles in the nonmagnetic carrier oils, i.e., mineral oil (MO) and synthetic oil with stabilizing additives. The prominent feature of these fluids is their propensity to the reversible transformation from fluid to semi-solid-state and vice versa within milliseconds under the external magnetic field. The long-time stability and low magnetorheological effect are still considered as one of the most critical problems that need to be solved. There are many methods to resolve this problem, and many researchers are working to improve their stabilization and MR effect. This study reviews the prevalent stabilization techniques, different preparation methods and tribological behaviour of these fluids under an external magnetic field. Additionally, applications of magnetorheological fluid (MRF), rheological models, temperature dependency, current scenarios and future directions are also discussed.

Arabian Journal for Science and Engineering, 2015

For machining operations during the last few decades, there has been major progress in developing... more For machining operations during the last few decades, there has been major progress in developing models for industries. This paper aimed to develop mathematical models using Design Expert 7.1 software to study the effect of cutting parameters on main cutting force, surface roughness and stress. Second objective of this research work was to optimize the machining process by finding the best parameters setting with defined goals for the variables. Results reveal that the value of main cutting force decreases with a decrease in the value of cutting speed and depth of cut. The most significant factors in case of surface roughness and stress are feed rate and depth of cut, respectively. Mathematical models have been developed for main cutting force, surface roughness and stress, and average errors of 3.87, 5.41 and 2.96 % were observed for the corresponding values and analogous trend lines of the plots, respectively. The optimal set of conditions possessing highest desirability value (0.617) and lowest surface roughness (out of eight solutions having the same desirability of 0.617) is as follows: cutting speed-138.29 m/min; feed rate-0.13 mm/rev; depth of cut-0.28 mm (input parameters) and main cutting force-219.273 N; surface roughness-0.439 µm; stress-5128.18 N/mm 2 (responses for input parameters).

Industrial Lubrication and Tribology, 2014

Purpose – In the present study, an attempt has been made to examine friction and wear behaviour o... more Purpose – In the present study, an attempt has been made to examine friction and wear behaviour of Ti-6Al-4V alloy sliding against EN-31 steel under lubricative media of common commercial grade oil (hydrol-68). The paper aims to discuss these issues. Design/methodology/approach – Tribological properties of Ti-6Al-4V under hydrol-68 as lubricative media are measured using multi-tribo tester. Lubricating oil samples at different normal loads have also been analysed with the help of laser net fines (LNF) as per ISO 4406:1999. Experiments have been designed by two level full factorial method. Findings – Experimental results indicate that the wear rate of Ti-6Al-4V alloy decreases as sliding speed increases. But it shows typical transition characteristics as the normal load increases; till 30 N wear rate decreases then it increases from 30 to 50 N. Also for all loads and at every speed, the average wear increases as the sliding distance increases. The average coefficient of friction of t...

The Journal of Men's Studies, 2015

Tribology Online, 2012

Friction and wear are the most commonly encountered industrial problems leading to the replacemen... more Friction and wear are the most commonly encountered industrial problems leading to the replacement of components and assemblies in engineering. There have been great advances in the development of aerospace technology because of the use of titanium alloys. Titanium alloys have wide range of applications for which they have received considerable interest recently because they show an astonishing range of mechanical properties. The present investigation covers the study of dry sliding friction and wear of the Ti6Al4V alloy, which alone covers about 50% of the total world production of titanium alloys. The main objective of this study is to investigate the dry sliding friction and wear behaviour of titanium alloy (Ti-6Al-4V) sliding against EN31 steel. The results show that the wear rate of the Ti6Al4V alloy decreases with increasing sliding velocity and decreasing normal load with few exceptions thus showing typical transition characteristics. The average coefficient of friction decreases as the normal load increases with few exceptions. Also the average coefficient of friction increases as the sliding distance increases for all loads and sliding velocities. The average length of biggest, medium and smallest wear debris was found to be 1.026 µm, 0.711 µm and 0.401 µm respectively.

Arabian Journal for Science and Engineering, 2013

Machining characteristics of titanium alloy grade-5 (Ti–6Al–4V) have been examined at different c... more Machining characteristics of titanium alloy grade-5 (Ti–6Al–4V) have been examined at different cutting speeds, feed rates and approaching angles under dry condition. It has been observed that with the increase in cutting speeds, the magnitude of cutting forces and tool tip temperature increase. If both cutting force and temperature level were considered together, the optimum approaching angle works out to be 45◦ and 90◦ for 49.5 and 76.7m/min, respectively. For 116.9m/min increase of cutting forces at 60◦ approaching angle can be attributed to low-shear angle which is function of the average chip thickness. Positive rake angle produces higher shear angle which leads to the reduction of cutting forces, tool tip temperature and thus help obtaining a better surface finish. Surface roughness measurements obtained prior and subsequent to the machining of titanium alloy (Ti–6Al–4V) were used to characterize the change in roughness caused by variation in machining parameters like cutting speed, feed rate and approaching angle. The average surface roughness is observed to be maximum at 0.11 mm/min and minimum at 0.04 mm/min feed rate for all approaching angles.

Industrial Lubrication and Tribology, 2014

Arabian Journal for Science and Engineering, 2013

Machining characteristics of titanium alloy grade-5 (Ti–6Al–4V) have been examined at different c... more Machining characteristics of titanium alloy grade-5 (Ti–6Al–4V) have been examined at different cutting speeds, feed rates and approaching angles under dry condition. It has been observed that with the increase in cutting speeds, the magnitude of cutting forces and tool tip temperature increase. If both cutting force and temperature level were considered together, the optimum approaching angle works out to be 45◦ and 90◦ for 49.5 and 76.7m/min, respectively. For 116.9m/min increase of cutting forces at 60◦ approaching angle can be attributed to low-shear angle which is function of the average chip thickness. Positive rake angle produces higher shear angle which leads to the reduction of cutting forces, tool tip temperature and thus help obtaining a better surface finish. Surface roughness measurements obtained prior and subsequent to the machining of titanium alloy (Ti–6Al–4V) were used to characterize the change in roughness caused by variation in machining parameters like cutting speed, feed rate and approaching angle. The average surface roughness is observed to be maximum at 0.11 mm/min and minimum at 0.04 mm/min feed rate for all approaching angles.