Santanu Das | Kalyani Government Engineering College (original) (raw)

Papers by Santanu Das

International Journal of the Analytic Hierarchy Process, 2015

Grinding is commonly used in industry for the finishing or semi-finishing of different mechanical... more Grinding is commonly used in industry for the finishing or semi-finishing of different mechanical components. In this process, a wheel is rotated at a high speed. The wheel is made of abrasive particles known as grits. During grinding, high grinding zone temperature is experienced leading to several grinding defects. To control these thermal defects grinding fluid is usually employed mainly to cool and lubricate the grinding region. However, most of the applied grinding fluid cannot reach the grinding zone as it is deflected by the stiff air layer formed around the wheel periphery. Several attempts have been made in the past to overcome this problem in order to guarantee better fluid delivery. In this paper, two newly developed methods, a pneumatic barrier and a compound nozzle are considered to serve this purpose. Grinding experiments are conducted on titanium grade-1 specimens under four environmental conditions, which include dry, flood cooling, flood cooling with pneumatic barrier set up and cooling using a compound nozzle. Under each environment, 10 grinding passes are undertaken using 10, 20 and 30 m infeed. Data obtained are used to optimize the grinding performance by employing the Analytic Hierarchy Process (AHP). The AHP results show compound nozzle fluid delivery at 20 m infeed to be the appropriate condition for grinding titanium grade-1 within this experimental domain. This condition is supposed to deliver grinding fluid deep into the grinding zone thereby controlling grinding temperature effectively and may be recommended to the industry.

IOP Conference Series: Materials Science and Engineering, 2018

Inconel used in industrial applications is usually subjected to extreme conditions of heat and pr... more Inconel used in industrial applications is usually subjected to extreme conditions of heat and pressure. Desirable material properties like high hardness and high compressive residual stresses are not always ensured by using conventional cooling methods, while grinding such alloys. However, with increasing hardness, cutting forces and energy requirement also increase naturally. Hence, a balance has to be obtained between the two. This paper uses soap water and liquid carbon dioxide as the grinding fluid during surface grinding of Inconel 718, a Nickel based alloy. A novel method to apply both soap water and liquid carbon dioxide is employed here. It is observed that minimum grinding force and high surface hardness are achieved using the soap water-liquid CO2 combination. Furthermore, ground surface quality is found to improve using liquid carbon dioxide.

Lubricants

The surface preparation of shiny stainless steels is a must for applying esthetic paints, effecti... more The surface preparation of shiny stainless steels is a must for applying esthetic paints, effective functional plasma spray coating, laser cladding, welding, etc., applications. The current work aims for effective surface roughening and erosion MRR of SS 304 work surface using SiC abrasive jet erosion and optimization of the process parameters. The response surface approach is used to design and conduct the studies using the Box–Behnken design method. The surface topography of the eroded surfaces is examined by a 2D profilometer, 3D profilometer, and scanning electron microscope (SEM). The abrasive grit size and working gas pressure greatly affect the surface roughness of SS 304 samples. The influence of the process parameters on the variation of these topographical features is analyzed and confirmed. The working jet pressure is seen to significantly impact erosion MRR. The lower working gas pressure shows a typical influence on Ra (surface preparation) and as pressure increases, er...

Lubricants

The surface preparation of shiny stainless steels is a must for applying esthetic paints, effecti... more The surface preparation of shiny stainless steels is a must for applying esthetic paints, effective functional plasma spray coating, laser cladding, welding, etc., applications. The current work aims for effective surface roughening and erosion MRR of SS 304 work surface using SiC abrasive jet erosion and optimization of the process parameters. The response surface approach is used to design and conduct the studies using the Box–Behnken design method. The surface topography of the eroded surfaces is examined by a 2D profilometer, 3D profilometer, and scanning electron microscope (SEM). The abrasive grit size and working gas pressure greatly affect the surface roughness of SS 304 samples. The influence of the process parameters on the variation of these topographical features is analyzed and confirmed. The working jet pressure is seen to significantly impact erosion MRR. The lower working gas pressure shows a typical influence on Ra (surface preparation) and as pressure increases, er...

Journal of the Association of Engineers, India, 2014

In grinding, high heat is generated at the grinding zone per unit volume of material removed. To ... more In grinding, high heat is generated at the grinding zone per unit volume of material removed. To control this temperature, generally, grinding fluid is employed. Due to formation of a stiff air layer around the grinding wheel, grinding fluid cannot enter easily inside the grinding zone. In this experimental work, formation of air layer around a rotating grinding wheel has been investigated to observe variation of air layer pressure around the wheel periphery under different wheel speeds. Bare wheel, rexine-pasted wheel and bare wheel with pneumatic barrier set up have been employed to find out their effect on formation of air layer. Significantly less air layer pressure is noted around the wheel with both faces rexine-pasted, and using pneumatic barrier set up. In aggregate, about 50% reduction in the air layer pressure is achieved in the pneumatic barrier set up compared to that with the rexine-pasted wheel. Pneumatic barrier set up is thus quite effective to facilitate grinding fluid reach deep inside the grinding zone.

International Journal of Abrasive Technology, 2015

High grinding zone temperature is the primary reason behind several grinding defects. To control ... more High grinding zone temperature is the primary reason behind several grinding defects. To control thermal defects, usually large quantity of grinding fluid is employed. However, much of applied grinding fluid is reported to be wasted because of the development of a stiff air layer surrounding the rotating wheel. In the present experimental work, an indigenously introduced setup utilising a pneumatic barrier is used for controlling the adverse effect of stiff air layer formed around the grinding wheel. Different parameters of the pneumatic barrier setup are optimised by using response surface methodology (RSM). Further, experiments are performed in surface grinding with the provision of pneumatic barrier. It is observed that applying conventional grinding fluid by providing the pneumatic barrier at optimised condition, tangential and normal force components are reduced significantly, and favourable grinding chips and good ground surface is generated in comparison with the conventionally used flood cooling.

Grinding of titanium alloy is difficult due to its high hot strength, poor thermal conductivity a... more Grinding of titanium alloy is difficult due to its high hot strength, poor thermal conductivity and high work hardenability. At the time of grinding operation, large amount of heat is generated. To control resulting temperature rise at the grinding zone, suitable coolant and/or lubricant is to be used along with selection of appropriate process parameters and grinding wheel. However, supplying grinding fluid inside the grinding zone is difficult, and it needs suitable method of application to control temperature to obtain quality ground specimen. In the present work, a comparative study has been done through experimental investigation between dry grinding, wet grinding using flood cooling, and grinding with grease. Workpiece quality, force needed, grinding-ratio, and chips formed have been observed and results are discussed. Better grindability has been found with the use of grease at 30 μm infeed than the other two conditions tested.

Advanced Materials Research, 2009

In grinding process, a stiff air layer is generated around the wheel periphery due to high surfac... more In grinding process, a stiff air layer is generated around the wheel periphery due to high surface speed of the porous grinding wheel. This stiff air layer restricts grinding fluid to reach deep inside the grinding zone. The formation of stiff air layer has been studied experimentally by obtaining the variation of air pressure around the wheel periphery under different wheel speeds. With the help of the experimental data, a mathematical model has been developed to predict the pressure of the stiff layer of air under different wheel speed. From the model it is found that at close proximity to the wheel, air pressure obtained is very high, and this establishes quantitatively the formation of stiff air layer around the grinding wheel.

Production Engineering, 2014

ABSTRACT Grinding fluid is commonly applied to control grinding defects caused by high grinding z... more ABSTRACT Grinding fluid is commonly applied to control grinding defects caused by high grinding zone temperature. Delivery of fluid to the grinding zone is obstructed by the formation of a stiff air layer around the grinding wheel. This results in huge wastage of grinding fluid. In the present paper, results of using a pneumatic barrier and a compound nozzle are discussed with respect to delivering fluid deep into the grinding zone. Grinding fluid passing through the grinding wheel contact zone is measured under different modes of fluid delivery using a flood cooling, or a compound, nozzle, with or without the application of a pneumatic barrier. It is found that the system using a pneumatic barrier with flood cooling nozzle, and that employing a compound nozzle perform better than the flood cooling nozzle. A compound nozzle along with a pneumatic barrier renders substantially less wastage of grinding fluid even at a low flow rate of grinding fluid. Above a fluid discharge of 475 ml/min, the compound nozzle alone shows effective penetration of grinding fluid through the grinding zone. Reduction of grinding force, specific energy and roughness of ground surface are obtained after using compound nozzle fluid delivery system. Compound nozzle may be used instead of flood cooling nozzle as it improves grinding performance even using 52.5 % less discharge of grinding fluid.

Grinding process is generally used for making products requiring high surface finish. However, du... more Grinding process is generally used for making products requiring high surface finish. However, due to high thermo-mechanical load, stresses are generated inside the ground workpiece. Residual stress, if tensile in nature, has detrimental effect on the workpiece. Thus, assessment of residual stress is important for fatigue analysis, safety design and strength evaluation. In this paper, a finite element thermo-mechanical model is used for evaluating distribution of stress induced during surface grinding of titanium Grade-1 flats. The stress generated in the product can be minimized by using coolant. Wet with pneumatic barrier condition gives more control on stress generation due to effective cooling. Stress generated during grinding can be controlled by controlling infeed also. Through analytical approach, it is found that simulation of experimental findings becomes possible. Therefore, using this technique, requirement of rigorous experimentation may be reduced significantly.

ABSTRACT A micromechanical approach is considered here to predict the deformation behaviour of Rh... more ABSTRACT A micromechanical approach is considered here to predict the deformation behaviour of Rheocast A356 (Al-Si-Mg) alloy. Two representative volume elements (RVEs) are modelled in the finite element (FE) framework. Two dimensional approximated microstructures are generated assuming elliptic grains, based on the grain size, shape factor and area fraction of the primary Al phase of the said alloy at different processing condition. Plastic instability is shown using stress and strain distribution between the Al rich primary and Si rich eutectic phases under different boundary conditions. Boundary conditions are applied on the approximated RVEs in such a manner, so that they represent the real life situation depending on their position on a cylindrical tensile test sample. FE analysis is carried out using commercial finite element code ABAQUS without specifying any damage or failure criteria. Micro-level in-homogeneity leads to incompatible deformation between the constituent phases of the rheocast alloy and steers plastic strain localisation. Plastic stain localised regions within the RVEs are predicted as the favourable sites for void nucleation. Subsequent growth of nucleated voids leads to final failure of the materials under investigation.

Http Dx Doi Org 10 1080 10426914 2013 773011, May 1, 2013

ABSTRACT Burr is observed on a machined job attached to its edge. Problem is experienced due to t... more ABSTRACT Burr is observed on a machined job attached to its edge. Problem is experienced due to the presence of burr in the production line affecting product quality and causing possible injury to an operator, and hence, a strategy for prevention or minimization of burr formation needs to be adopted. Usually, deburring is done to eliminate burrs in industry incurring additional cost. To tackle this problem, many investigations were made in the past on formation of burr and its minimization. The aim of the present work is to find out the condition to suppress burr formation effectively during face milling of 45C8 steel specimens, which are widely used in Indian Railways. First, in-plane exit angle is varied, and it shows that an in-plane exit angle of 30° reduces burr height remarkably. Next, with the provision of 15° exit edge bevel, it is noted that burr size can be reduced effectively to a negligible value by keeping an in-plane exit angle of 60°.

Proceedings of the 36th International MATADOR Conference, 2010

Cladding is usually employed for modifying surface of components and structures exposed to a corr... more Cladding is usually employed for modifying surface of components and structures exposed to a corrosive environment. This process increases service life of a component or structure, thereby lowering frequent maintenance or replacement. Components or structures can be clad with corrosion resistant alloys up to a desired thickness. Arc welding processes are often used for cladding. Since clad materials are basically of different compositions, they are dissimilar in nature. Gas metal arc welding is often employed for cladding. In this work, cladding of austenitic stainless steel (316) is carried out on low alloy steel flat under different process parameters. Metallographic study and immersion type corrosion tests are performed on the clad specimens at different locations of it. The results of the metallographic study are discussed in this paper. Corrosion tests performed on clad specimens indicate substantially less corrosion pits present on the surface of the clad portions than that on the surface of the unclad portion. At a weld voltage of 26 V, weld current of 145 A, and weld speed of 535.8 mm/min, with a heat input of 0.338 kJ/mm, corrosion rate is observed to be the minimum in the domain of experiments conducted, and hence, may be recommended.

Advanced Materials Research, 2012

ABSTRACT A Stiff Air Layer, Formed around a Rotating Grinding Wheel, Tends to Restrict Grinding F... more ABSTRACT A Stiff Air Layer, Formed around a Rotating Grinding Wheel, Tends to Restrict Grinding Fluid Penetrate Deep inside the Grinding Zone. for this, much Fluid Is Wasted, and Thermal Defects in Grinding May Not Be Controlled. in the Present Experimental Work, a Flood Cooling System with Pneumatic Barrier Is Used for Delivering Grinding Fluid. the Pneumatic Barrier Breaks the Stiff Air Layer, and Therefore, Grinding Fluid Reaches Grinding Zone. an Exotic Nickel Base Alloy, Inconel 600, Is Taken for Surface Grinding Experiments Using an Infeed of 30 µm under Different Environmental Conditions. the Effect of Different Experimental Conditions Is Investigated in Respect of Grinding Force, Chip Formation, Surface Quality and Wheel Condition. the Experimental Result Shows that Grinding Forces and Wheel Wear Are Remarkably Reduced, and Favourable Chips and Good Surface Quality Are Obtained with the Use of Flood Cooling along with Pneumatic Barrier Setup Compared to other Environmental Conditions.

High grinding zone temperature often results in several grinding defects. For controlling this, u... more High grinding zone temperature often results in several grinding defects. For controlling this, usually large amount of grinding fluid is applied. However, synthetic grinding fluid or cutting fluid has some adverse impact on environment, and, hence, researchers are trying to reduce the application of grinding fluid. In this experimental investigation, a specially developed compound nozzle is used for delivering grinding fluid. Fluid may reach easily into grinding zone at low discharge by using this nozzle. Discharge of the nozzle is about 52% less than conventional flood cooling. Grinding results obtained under different environment are compared. It is found that better grinding performance is obtained by using this compound nozzle than conventional flood cooling grinding; as consumption of grinding fluid is substantially reduced, use of compound nozzle may be more economical and advantageous to control industrial pollution.

Grinding fluids, commonly termed as coolants, play a vital role in controlling the heat produced ... more Grinding fluids, commonly termed as coolants, play a vital role in controlling the heat produced during the process and the consequent thermal damage associated with it. These fluids are to be applied into the grinding zone in a suitable and effective manner, so as to reduce the heat generated and to carry away the heat produced as well as for efficient chip disposal. In this work, three different methods, namely normal flood cooling, mist cooling and multi-nozzle cooling arrangements are employed for delivering the fluid into the grinding zone. A comparative study is made among the three coolant delivery systems to assess the grinding performance. It is found that the multi-nozzle cooling arrangement produces best results in terms of force requirement and ground surface quality.

International Journal of Machine Tools and Manufacture, 2011

In grinding, high specific heat is generated, and hence, appropriate control of temperature throu... more In grinding, high specific heat is generated, and hence, appropriate control of temperature through effective flow of grinding fluid is necessary to obtain a quality ground surface. It is known that in conventional fluid delivery method, most of fluid is wasted due to presence of a stiff air layer around the grinding wheel. This air layer is generated around the

International Journal of Abrasive Technology, 2014

ABSTRACT Grinding fluid, apart from controlling temperature produced at the wheel-work contact zo... more ABSTRACT Grinding fluid, apart from controlling temperature produced at the wheel-work contact zone by way of cooling also helps in lubrication which is achieved by reduction of friction at the wheel-workpiece interface. In the present experimental investigation, grinding fluid is delivered into the grinding zone by a multi-nozzle system in order to determine grindability of low alloy steel at different fluid concentrations. A comparative study has been made among dry and wet grinding using three different coolant concentrations, considering various response parameters, to assess grinding performance at a particular in feed. It is found that high concentration of oil in the fluid produced good results in terms of force requirement and surface roughness.

International Journal of the Analytic Hierarchy Process, 2015

Grinding is commonly used in industry for the finishing or semi-finishing of different mechanical... more Grinding is commonly used in industry for the finishing or semi-finishing of different mechanical components. In this process, a wheel is rotated at a high speed. The wheel is made of abrasive particles known as grits. During grinding, high grinding zone temperature is experienced leading to several grinding defects. To control these thermal defects grinding fluid is usually employed mainly to cool and lubricate the grinding region. However, most of the applied grinding fluid cannot reach the grinding zone as it is deflected by the stiff air layer formed around the wheel periphery. Several attempts have been made in the past to overcome this problem in order to guarantee better fluid delivery. In this paper, two newly developed methods, a pneumatic barrier and a compound nozzle are considered to serve this purpose. Grinding experiments are conducted on titanium grade-1 specimens under four environmental conditions, which include dry, flood cooling, flood cooling with pneumatic barrier set up and cooling using a compound nozzle. Under each environment, 10 grinding passes are undertaken using 10, 20 and 30 m infeed. Data obtained are used to optimize the grinding performance by employing the Analytic Hierarchy Process (AHP). The AHP results show compound nozzle fluid delivery at 20 m infeed to be the appropriate condition for grinding titanium grade-1 within this experimental domain. This condition is supposed to deliver grinding fluid deep into the grinding zone thereby controlling grinding temperature effectively and may be recommended to the industry.

IOP Conference Series: Materials Science and Engineering, 2018

Inconel used in industrial applications is usually subjected to extreme conditions of heat and pr... more Inconel used in industrial applications is usually subjected to extreme conditions of heat and pressure. Desirable material properties like high hardness and high compressive residual stresses are not always ensured by using conventional cooling methods, while grinding such alloys. However, with increasing hardness, cutting forces and energy requirement also increase naturally. Hence, a balance has to be obtained between the two. This paper uses soap water and liquid carbon dioxide as the grinding fluid during surface grinding of Inconel 718, a Nickel based alloy. A novel method to apply both soap water and liquid carbon dioxide is employed here. It is observed that minimum grinding force and high surface hardness are achieved using the soap water-liquid CO2 combination. Furthermore, ground surface quality is found to improve using liquid carbon dioxide.

Lubricants

The surface preparation of shiny stainless steels is a must for applying esthetic paints, effecti... more The surface preparation of shiny stainless steels is a must for applying esthetic paints, effective functional plasma spray coating, laser cladding, welding, etc., applications. The current work aims for effective surface roughening and erosion MRR of SS 304 work surface using SiC abrasive jet erosion and optimization of the process parameters. The response surface approach is used to design and conduct the studies using the Box–Behnken design method. The surface topography of the eroded surfaces is examined by a 2D profilometer, 3D profilometer, and scanning electron microscope (SEM). The abrasive grit size and working gas pressure greatly affect the surface roughness of SS 304 samples. The influence of the process parameters on the variation of these topographical features is analyzed and confirmed. The working jet pressure is seen to significantly impact erosion MRR. The lower working gas pressure shows a typical influence on Ra (surface preparation) and as pressure increases, er...

Lubricants

The surface preparation of shiny stainless steels is a must for applying esthetic paints, effecti... more The surface preparation of shiny stainless steels is a must for applying esthetic paints, effective functional plasma spray coating, laser cladding, welding, etc., applications. The current work aims for effective surface roughening and erosion MRR of SS 304 work surface using SiC abrasive jet erosion and optimization of the process parameters. The response surface approach is used to design and conduct the studies using the Box–Behnken design method. The surface topography of the eroded surfaces is examined by a 2D profilometer, 3D profilometer, and scanning electron microscope (SEM). The abrasive grit size and working gas pressure greatly affect the surface roughness of SS 304 samples. The influence of the process parameters on the variation of these topographical features is analyzed and confirmed. The working jet pressure is seen to significantly impact erosion MRR. The lower working gas pressure shows a typical influence on Ra (surface preparation) and as pressure increases, er...

Journal of the Association of Engineers, India, 2014

In grinding, high heat is generated at the grinding zone per unit volume of material removed. To ... more In grinding, high heat is generated at the grinding zone per unit volume of material removed. To control this temperature, generally, grinding fluid is employed. Due to formation of a stiff air layer around the grinding wheel, grinding fluid cannot enter easily inside the grinding zone. In this experimental work, formation of air layer around a rotating grinding wheel has been investigated to observe variation of air layer pressure around the wheel periphery under different wheel speeds. Bare wheel, rexine-pasted wheel and bare wheel with pneumatic barrier set up have been employed to find out their effect on formation of air layer. Significantly less air layer pressure is noted around the wheel with both faces rexine-pasted, and using pneumatic barrier set up. In aggregate, about 50% reduction in the air layer pressure is achieved in the pneumatic barrier set up compared to that with the rexine-pasted wheel. Pneumatic barrier set up is thus quite effective to facilitate grinding fluid reach deep inside the grinding zone.

International Journal of Abrasive Technology, 2015

High grinding zone temperature is the primary reason behind several grinding defects. To control ... more High grinding zone temperature is the primary reason behind several grinding defects. To control thermal defects, usually large quantity of grinding fluid is employed. However, much of applied grinding fluid is reported to be wasted because of the development of a stiff air layer surrounding the rotating wheel. In the present experimental work, an indigenously introduced setup utilising a pneumatic barrier is used for controlling the adverse effect of stiff air layer formed around the grinding wheel. Different parameters of the pneumatic barrier setup are optimised by using response surface methodology (RSM). Further, experiments are performed in surface grinding with the provision of pneumatic barrier. It is observed that applying conventional grinding fluid by providing the pneumatic barrier at optimised condition, tangential and normal force components are reduced significantly, and favourable grinding chips and good ground surface is generated in comparison with the conventionally used flood cooling.

Grinding of titanium alloy is difficult due to its high hot strength, poor thermal conductivity a... more Grinding of titanium alloy is difficult due to its high hot strength, poor thermal conductivity and high work hardenability. At the time of grinding operation, large amount of heat is generated. To control resulting temperature rise at the grinding zone, suitable coolant and/or lubricant is to be used along with selection of appropriate process parameters and grinding wheel. However, supplying grinding fluid inside the grinding zone is difficult, and it needs suitable method of application to control temperature to obtain quality ground specimen. In the present work, a comparative study has been done through experimental investigation between dry grinding, wet grinding using flood cooling, and grinding with grease. Workpiece quality, force needed, grinding-ratio, and chips formed have been observed and results are discussed. Better grindability has been found with the use of grease at 30 μm infeed than the other two conditions tested.

Advanced Materials Research, 2009

In grinding process, a stiff air layer is generated around the wheel periphery due to high surfac... more In grinding process, a stiff air layer is generated around the wheel periphery due to high surface speed of the porous grinding wheel. This stiff air layer restricts grinding fluid to reach deep inside the grinding zone. The formation of stiff air layer has been studied experimentally by obtaining the variation of air pressure around the wheel periphery under different wheel speeds. With the help of the experimental data, a mathematical model has been developed to predict the pressure of the stiff layer of air under different wheel speed. From the model it is found that at close proximity to the wheel, air pressure obtained is very high, and this establishes quantitatively the formation of stiff air layer around the grinding wheel.

Production Engineering, 2014

ABSTRACT Grinding fluid is commonly applied to control grinding defects caused by high grinding z... more ABSTRACT Grinding fluid is commonly applied to control grinding defects caused by high grinding zone temperature. Delivery of fluid to the grinding zone is obstructed by the formation of a stiff air layer around the grinding wheel. This results in huge wastage of grinding fluid. In the present paper, results of using a pneumatic barrier and a compound nozzle are discussed with respect to delivering fluid deep into the grinding zone. Grinding fluid passing through the grinding wheel contact zone is measured under different modes of fluid delivery using a flood cooling, or a compound, nozzle, with or without the application of a pneumatic barrier. It is found that the system using a pneumatic barrier with flood cooling nozzle, and that employing a compound nozzle perform better than the flood cooling nozzle. A compound nozzle along with a pneumatic barrier renders substantially less wastage of grinding fluid even at a low flow rate of grinding fluid. Above a fluid discharge of 475 ml/min, the compound nozzle alone shows effective penetration of grinding fluid through the grinding zone. Reduction of grinding force, specific energy and roughness of ground surface are obtained after using compound nozzle fluid delivery system. Compound nozzle may be used instead of flood cooling nozzle as it improves grinding performance even using 52.5 % less discharge of grinding fluid.

Grinding process is generally used for making products requiring high surface finish. However, du... more Grinding process is generally used for making products requiring high surface finish. However, due to high thermo-mechanical load, stresses are generated inside the ground workpiece. Residual stress, if tensile in nature, has detrimental effect on the workpiece. Thus, assessment of residual stress is important for fatigue analysis, safety design and strength evaluation. In this paper, a finite element thermo-mechanical model is used for evaluating distribution of stress induced during surface grinding of titanium Grade-1 flats. The stress generated in the product can be minimized by using coolant. Wet with pneumatic barrier condition gives more control on stress generation due to effective cooling. Stress generated during grinding can be controlled by controlling infeed also. Through analytical approach, it is found that simulation of experimental findings becomes possible. Therefore, using this technique, requirement of rigorous experimentation may be reduced significantly.

ABSTRACT A micromechanical approach is considered here to predict the deformation behaviour of Rh... more ABSTRACT A micromechanical approach is considered here to predict the deformation behaviour of Rheocast A356 (Al-Si-Mg) alloy. Two representative volume elements (RVEs) are modelled in the finite element (FE) framework. Two dimensional approximated microstructures are generated assuming elliptic grains, based on the grain size, shape factor and area fraction of the primary Al phase of the said alloy at different processing condition. Plastic instability is shown using stress and strain distribution between the Al rich primary and Si rich eutectic phases under different boundary conditions. Boundary conditions are applied on the approximated RVEs in such a manner, so that they represent the real life situation depending on their position on a cylindrical tensile test sample. FE analysis is carried out using commercial finite element code ABAQUS without specifying any damage or failure criteria. Micro-level in-homogeneity leads to incompatible deformation between the constituent phases of the rheocast alloy and steers plastic strain localisation. Plastic stain localised regions within the RVEs are predicted as the favourable sites for void nucleation. Subsequent growth of nucleated voids leads to final failure of the materials under investigation.

Http Dx Doi Org 10 1080 10426914 2013 773011, May 1, 2013

ABSTRACT Burr is observed on a machined job attached to its edge. Problem is experienced due to t... more ABSTRACT Burr is observed on a machined job attached to its edge. Problem is experienced due to the presence of burr in the production line affecting product quality and causing possible injury to an operator, and hence, a strategy for prevention or minimization of burr formation needs to be adopted. Usually, deburring is done to eliminate burrs in industry incurring additional cost. To tackle this problem, many investigations were made in the past on formation of burr and its minimization. The aim of the present work is to find out the condition to suppress burr formation effectively during face milling of 45C8 steel specimens, which are widely used in Indian Railways. First, in-plane exit angle is varied, and it shows that an in-plane exit angle of 30° reduces burr height remarkably. Next, with the provision of 15° exit edge bevel, it is noted that burr size can be reduced effectively to a negligible value by keeping an in-plane exit angle of 60°.

Proceedings of the 36th International MATADOR Conference, 2010

Cladding is usually employed for modifying surface of components and structures exposed to a corr... more Cladding is usually employed for modifying surface of components and structures exposed to a corrosive environment. This process increases service life of a component or structure, thereby lowering frequent maintenance or replacement. Components or structures can be clad with corrosion resistant alloys up to a desired thickness. Arc welding processes are often used for cladding. Since clad materials are basically of different compositions, they are dissimilar in nature. Gas metal arc welding is often employed for cladding. In this work, cladding of austenitic stainless steel (316) is carried out on low alloy steel flat under different process parameters. Metallographic study and immersion type corrosion tests are performed on the clad specimens at different locations of it. The results of the metallographic study are discussed in this paper. Corrosion tests performed on clad specimens indicate substantially less corrosion pits present on the surface of the clad portions than that on the surface of the unclad portion. At a weld voltage of 26 V, weld current of 145 A, and weld speed of 535.8 mm/min, with a heat input of 0.338 kJ/mm, corrosion rate is observed to be the minimum in the domain of experiments conducted, and hence, may be recommended.

Advanced Materials Research, 2012

ABSTRACT A Stiff Air Layer, Formed around a Rotating Grinding Wheel, Tends to Restrict Grinding F... more ABSTRACT A Stiff Air Layer, Formed around a Rotating Grinding Wheel, Tends to Restrict Grinding Fluid Penetrate Deep inside the Grinding Zone. for this, much Fluid Is Wasted, and Thermal Defects in Grinding May Not Be Controlled. in the Present Experimental Work, a Flood Cooling System with Pneumatic Barrier Is Used for Delivering Grinding Fluid. the Pneumatic Barrier Breaks the Stiff Air Layer, and Therefore, Grinding Fluid Reaches Grinding Zone. an Exotic Nickel Base Alloy, Inconel 600, Is Taken for Surface Grinding Experiments Using an Infeed of 30 µm under Different Environmental Conditions. the Effect of Different Experimental Conditions Is Investigated in Respect of Grinding Force, Chip Formation, Surface Quality and Wheel Condition. the Experimental Result Shows that Grinding Forces and Wheel Wear Are Remarkably Reduced, and Favourable Chips and Good Surface Quality Are Obtained with the Use of Flood Cooling along with Pneumatic Barrier Setup Compared to other Environmental Conditions.

High grinding zone temperature often results in several grinding defects. For controlling this, u... more High grinding zone temperature often results in several grinding defects. For controlling this, usually large amount of grinding fluid is applied. However, synthetic grinding fluid or cutting fluid has some adverse impact on environment, and, hence, researchers are trying to reduce the application of grinding fluid. In this experimental investigation, a specially developed compound nozzle is used for delivering grinding fluid. Fluid may reach easily into grinding zone at low discharge by using this nozzle. Discharge of the nozzle is about 52% less than conventional flood cooling. Grinding results obtained under different environment are compared. It is found that better grinding performance is obtained by using this compound nozzle than conventional flood cooling grinding; as consumption of grinding fluid is substantially reduced, use of compound nozzle may be more economical and advantageous to control industrial pollution.

Grinding fluids, commonly termed as coolants, play a vital role in controlling the heat produced ... more Grinding fluids, commonly termed as coolants, play a vital role in controlling the heat produced during the process and the consequent thermal damage associated with it. These fluids are to be applied into the grinding zone in a suitable and effective manner, so as to reduce the heat generated and to carry away the heat produced as well as for efficient chip disposal. In this work, three different methods, namely normal flood cooling, mist cooling and multi-nozzle cooling arrangements are employed for delivering the fluid into the grinding zone. A comparative study is made among the three coolant delivery systems to assess the grinding performance. It is found that the multi-nozzle cooling arrangement produces best results in terms of force requirement and ground surface quality.

International Journal of Machine Tools and Manufacture, 2011

In grinding, high specific heat is generated, and hence, appropriate control of temperature throu... more In grinding, high specific heat is generated, and hence, appropriate control of temperature through effective flow of grinding fluid is necessary to obtain a quality ground surface. It is known that in conventional fluid delivery method, most of fluid is wasted due to presence of a stiff air layer around the grinding wheel. This air layer is generated around the

International Journal of Abrasive Technology, 2014

ABSTRACT Grinding fluid, apart from controlling temperature produced at the wheel-work contact zo... more ABSTRACT Grinding fluid, apart from controlling temperature produced at the wheel-work contact zone by way of cooling also helps in lubrication which is achieved by reduction of friction at the wheel-workpiece interface. In the present experimental investigation, grinding fluid is delivered into the grinding zone by a multi-nozzle system in order to determine grindability of low alloy steel at different fluid concentrations. A comparative study has been made among dry and wet grinding using three different coolant concentrations, considering various response parameters, to assess grinding performance at a particular in feed. It is found that high concentration of oil in the fluid produced good results in terms of force requirement and surface roughness.