Journal of the Association of Engineers, India

Bijoy Mandal ¹, Anirban Sarkar ¹, Debashis Biswas ¹, Santanu Das ¹, Simul Banerjee ²

Affiliations
1 Department of Mechanical Engineering, Kalyani Government Engineering College, Kalyani-741235, IN
2 Department of Mechanical Engineering, Jadavpur University, Kolkata- 700 032, IN

Abstract

Conventional fluid delivery system is not much effective to reduce heat generation due to presence of a stiff air layer covering the periphery of grinding wheel. Thermal damages in grinding a super alloy are stringent and problematic. In this paper, a report on the experimental investigation carried out on grinding a nickel based super alloy, Inconnel-600 is made. Different infeeds are considered with dry, wet and wet with pneumatic barrier conditions. To break the stiff air layer covering grinding wheel, high pressure air jet is employed just above the conventional grinding fluid nozzle to facilitate grinding fluid reach the wheel-workpiece interface area. This is termed as a pneumatic barrier. Grinding performance under these environmental conditions has been investigated. Results show better grinding performance with the application of pneumatic barrier in the wet condition as it tends to facilitate fluid reach deep inside the grinding zone effectively.

Keywords

Surface Grinding, Grinding Fluid, Air Layer, Pneumatic Barrier; Grinding Chip, Surface Roughness, Grinding Forces, Flood Cooling Nozzle, Pneumatic Barrier Nozzle, Inconnel-600.

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Bijoy Mandal ¹, Santanu Das ¹

Affiliations
1 Department of Mechanical Engineering, Kalyani Government Engineering College, Kalyani, Nadia – 741235, West Bengal, IN

Abstract

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.

Keywords

Grinding, Grinding Wheel, Air Layer, Rexine-Pasted Wheel, Pneumatic Barrier, Compressed Air.

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Bijoy Mandal ¹, Debashis Biswas ¹, Anirban Sarkar ¹, Santanu Das ¹, Simul Banerjee ²

Affiliations
1 Department of Mechanical Engineering, Kalyani Government Engineering College, Kalyani-741235, IN
2 Department of Mechanical Engineering, Jadavpur University, Kolkata-700032, IN

Abstract

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.

Keywords

Surface Grinding, Compound Nozzle, Grinding Fluid, Surface Roughness, Flood Cooling.

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Sirsendu Mahata ¹, Jayanta Mistri ¹, Bijoy Mandal ¹, Santanu Das ¹

Affiliations
1 Dept. of Mechanical Engineering, Kalyani Government Engineering College, Kalyani–741 235, West Bengal, IN

Abstract

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.

Keywords

Surface Grinding, Flood Cooling, Mist Cooling, Multi-Nozzle.

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Subrata Kumar Majumder ¹, Bijoy Mandal ¹, Santanu Das ¹, Probal Kumar Das ²

Affiliations
1 Department of Mechanical Engineering, Kalyani Government Engineering College, Kalyani-741235, West Bengal, IN
2 CSIR-Central Glass and Ceramic Research Institute, Jadavpur, Kolkata-700032, IN

Abstract

In Abrasive Water Jet Machining (AWJM), abrasive particles suspended in high pressure water are impinged on work surface for removal of excess materials. A nozzle is fitted in front of workpiece to provide high velocity jet. In this work, appropriate machining condition is tried to evaluate to yield minimum surface roughness by employing Response Surface Methodology (RSM) while machining low carbon steel. Radius of curvature is also observed during abrasive water jet machining. A statistical model is generated for predicting surface roughness. It is observed that at low feed rate condition, better surface is obtained expectedly.

Keywords

Abrasive Water Jet Machining, AWJM, Optimisation, Response Surface Methodology, RSM, Surface Roughness.

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Arnab Kundu ¹, Manish Mukhopadhyay ², Ayan Banerjee ², Sirsendu Mahata ², Bijoy Mandal ², Santanu Das ²

Affiliations
1 Department of Mechanical Engineering, JIS College of Engineering, Phase III, Kalyani-741235, West Bengal, IN
2 Department of Mechanical Engineering, Kalyani Government Engineering College, Kalyani - 741235, West Bengal, IN

Abstract

In the ever prospering manufacturing sector, titanium is considered as an important material due to its mechanical properties, but grinding of titanium is quite a challenging task that needs necessary attention in order to improve its grindability. Past research works reported the success of sub-zero degree cooling for enhancing grindability of several materials. The present experimental work explores the effect of application of environment friendly liquid CO₂ during grinding of titanium grade I alloy compared to that under dry condition. Grindability of silicon carbide and alumina wheel is investigated and compared. Experimental results indicate that alumina wheel performs better with liquid CO₂ than SiC wheel and that in dry condition while grinding titanium grade I. Therefore, liquid CO₂ based cooling system may be used in industry with alumina wheel when grinding titanium grade I.

Keywords

Grinding, Grindability, Sub-Zero, Cooling, Titanium, Alumina, SiC, CO₂.

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Rajib Das ¹, Bijoy Mandal ¹, Santanu Das ¹

Affiliations
1 Department of Mechanical Engineering, Kalyani Government Engineering College, Kalyani-741235, West Bengal, IN

Abstract

Burrs are formed during various machining processes. These burrs result in difficulty in assembling operations. Being sharp, burrs may injure operators, cause electric short circuit problem, poor aesthetics of component, etc. So, deburring is commonly required to remove burrs. In the present work, drilling burrs formed on low alloy steel workpieces are tried to be removed by electro discharge machining. Electrolytic copper of 16.88 mm diameter is used as EDM tool which is made cathode and workpiece as anode. Parameters varied are peak current and pulse-on time whereas parameters such as duty factor, sparking time, lifting time, sensitivity, anti arcing, sparking gap voltage are kept constant. Peak currents are varied in the range of 4A-10A, and 50 ps, 100 ps, and 200 ps pulse-on time are taken. Initially sparking is found to be concentrated in a small area since only the burrs are attacked by the tool. When sparking spreads to the whole periphery of the tool, it indicates complete burr removal. The time taken for complete burr removal and surface roughness of specimen after deburring operation is measured. Some thickness loss of specimen has also been observed. Deburring time is found to be reduced with increase in peak current and pulseon time. At smaller values of peak current and pulse-on time, surface roughness and thickness loss are lower, but deburring time increases due to low energy of spark, which results in less heat generation and lesser melting and evaporation of burrs. Small depth of crater formed at low peak current and pulse-on time may be responsible for lower surface roughness. Parameters are optimized in order to obtain minimum deburring time, thickness loss and surface roughness.

Keywords

EDM, Burr, Deburring, Deburring Time, Surface Roughness, Thickness Loss, RSM.

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Krishnendu Mondal ¹, Anjan Kumar Adak ², Subhasish Chatterjee ², Bijoy Mandal ², Santanu Das ²

Affiliations
1 Mechanical Engineering Department, Bankura Unnayani Institute of Engineering, Bankura-722146, IN
2 Mechanical Engineering Department, Kalyani Government Engineering College, Kalyani- 741235, IN

Abstract

Employing conventional machining operations in material removal type manufacturing processes for processing difficult-to-machine hard materials through some ways and means is the focus of research by machining research groups across the globe since long. This gives considerable advantages over the grinding process in terms of higher material removal rate, better surface integrity of the work surface, etc., although grinding is commonly used for material removal of quite hard materials along with their finishing. In this paper, machinability of hard AISI 4340 steel is explored employing groove-type chip breaking coated carbide inserts under various cutting velocity and feed at dry condition. Hardened AISI 4340 is considered to be a difficult-to-machine material, and hence, recommendable machining conditions need to be found out. Favourable flat continuous chip is acquired at a cutting velocity of 231 m/min and at a feed of 0.08 mm/rev. At 391 m/min cutting velocity, cutting edges are detected to have worn-out quite fast.

Keywords

Machining, Turning, Cutting Force, Chip, Insert, Coated Carbide.

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