WASET.pdf

2018

Technological advancements in the development of cutting tools and coolant/lubricant chemistry have enhanced the machining capabilities of hard materials under higher machining conditions. Generation of high temperatures at the cutting zone during machining is one of the most important and pertinent problems which adversely affect the tool life and surface finish of the machined components. Generally, cutting fluids and solid lubricants are used to overcome the problem of heat generation, which is not effectively addressing the problems. With technological advancements in the field of tribology, nano-level particulate solid lubricants are being used nowadays in machining operations, especially in the areas of turning and grinding. The present investigation analyses the effect of using nano-particulate graphite powder as lubricant in the turning of AISI 1040 steel under variable machining conditions and to study its effect on cutting forces, tool temperature and surface roughness of ...

The past few decades have witnessed significant advancements in turning processes, cutting tools and coolant/lubricant chemistry. These developments have enhanced the machining capabilities of hard materials when machining at higher cutting conditions. Turning, being characterized by the development of high temperatures at the cutting zone, is critical with respect to the tool life and surface finish apart from other machining results like the forces generated. This phenomenon of heat generation at the cutting zone plays a negative role during turning operations due to their peculiar characteristics such as poor thermal conductivity, high strength at elevated temperature, resistance to wear and chemical degradation. Cutting fluids and solid lubricants are generally used to overcome the problem of heat generation at the cutting zone. The use of cutting fluids in the conventional way may not effectively control the heat generated in turning operation. Moreover, cutting fluids are a major source of pollution. With the advancement in technology, nano-level particulate solid lubricants are being used nowadays in machining operations, especially grinding and turning. The present work deals with the investigation of using nano-level particulate graphite powder as a solid lubricant and various tests were conducted by machining AISI 1040 steel using tungsten carbide inserts. The experiments were conducted by taking into account the parameters like feed rate ranging from 0.05 mm/rev to 0.125 mm/rev, cutting speed ranging from 51 m/min to 192.6 m/min and depth of cut from 0.25 mm to 1 mm. Four levels of each parameter are considered for experimentation. The results indicate that with the decrease in the nano-sized graphite powder, there is an increase of cutting forces – feed force, cutting force and thrust force. The temperatures at the tool–chip interface also increases with the decrease in the lubricant size. It is found that the surface roughness of the workpiece after machining deteriorated due to the size of the lubricant particle.

Liberation of heat and generation of friction associated with any machining operation ever pose a problem which not only reduce the tool life but also impair quality of the product. Cutting fluids have been the conventional choice to curtail friction and temperatures in machining because of its lubrication and cooling actions. However, considering health hazards posed by the conventional cutting fluids to health of the workers and ecology, the quest is towards identifying alternative strategies to the usual flood application. Selection and use of proper lubricant that can improve the overall cutting phenomena which is an important aspect in reducing the cutting forces and temperatures The present work studies the use of nano cutting fluids in MQL which is a minimal cutting fluid technique, for turning operation using HSS and cemented carbide tools. Development of nano materials by nanotechnology technique, dispersing them in the cutting fluid improve the effectiveness of the cutting fluid and hence nano graphite powder is selected of particle size 80 nm in varying proportions i.e. 0.0%, 0.1%, 0.3% and 0.5% by weight are mixed in water soluble oil and applied drop by drop. Experimentation is carried out at different flow rates like 5 ml/min 10 ml/min and 15 ml/min with nanoparticle suspended fluids along with dry machining, flood coolant machining under constant cutting conditions. Experimental results are very encouraging with much reduction in surface roughness, tool flank wear, temperatures and cutting forces is observed in fluids with nanoparticle inclusions. Different properties of the nanofluids are estimated through a series of standard tests.

Proceedings of the Institution of Mechanical Engineers, Part J: Journal of Engineering Tribology, 2010

Machining is one of the most fundamental and indispensable processes of the manufacturing industry. The heat generated in the cutting zone during machining is critical in deciding the workpiece quality. Though cutting fluids are widely employed to carry away the heat in machining, their usage poses threat to ecology and the health of workers. Hence, there arises a need to identify eco-friendly and user-friendly alternatives to conventional cutting fluids. Modern tribology has facilitated the use of solid lubricants. The present work features a specific study of the application of solid lubricants in turning of AISI1040 steel with carbide tool. Results show considerable improvement in reducing the cutting forces, coefficient of friction between chip and tool interface, average tool flank wear, and the surface roughness of the machined surface with solid lubricants. Among the selected lubricating conditions boric acid performed well compared to graphite. Chip thickness ratio is also e...

Now a day's turning process is a widely used metal removal process in manufacturing industry that involves generation of high cutting forces and temperature. Lubrication becomes critical to minimize the effect of these forces and temperature on cutting tool and work piece. For this specific study investigation carried out to increase the surface finish of the work piece machined on lathe with addition of nano particles were synthesized by solution combustion process and size was found to be 28 nm from X-Ray Diffraction [XRD]. A thin layer of Al 2 O 3 nano particles on steel can be obtained by various means i.e., liquid and solid process of particle deposition under various machining process. While turning of mild steel rod, three parameters are varied i.e., spindle speed, feed rate and depth of cut. During machining Al 2 O 3 nano particles are sprayed over it. This will lead to form a thin layer over the surface that will change in properties like surface roughness and hardness. Observed better surface roughness for coated material compared to that of base material. Coating thickness also observed at various conditions during machining process.

Procedia Manufacturing, 2019

Increasing production quality and minimizing costs in machining process have become an important aspect for green machining. In order for this to be sustained, high concern towards human health and high environmental awareness has resulted to the minimization and elimination of cutting fluids. Therefore, this research project aims at investigating the feasibility of some selected nano-particles dispersed in water as the base fluids. This is deemed a promising solution due to cooling and lubricating attributes of nano-fluids. In this case Al2O3, TiO2 and SiO2 nanoparticles were individually dispersed in water and then used to determine the variation of temperature with machining time and also the surface morphology of chip formation observed from mild steel subjected to an end milling operation in a vertical milling machine. Two pass end milling operation was carried out on the work piece while monitoring temperature response at 30 seconds interval for each trial of experiment with K thermocouple. The mean temperature distribution result obtained were 65.977ºC, 37.542ºC, 36.868ºC and 36.5796ºC for dry, TiO2, SiO2 and Al2O3 water based nano-fluids. The results showed that Al2O3 water base nano-coolant performed better in all the 5g/L nanoparticle concentration, nano-fluids in terms of heat transfer because it had the least mean temperature when compared to dry machining. In conclusion, 5g/L concentration of nano-coolants were efficient in machining but can be improved further by optimization.

Minimum quantity lubrication (MQL) has proved to be a sustainable method which can replace flood cooling for the application of cutting fluid in the metal cutting operation. Addition of nanoparticles in the cutting fluid may enhance the cooling and lubricating properties of the base fluid. Present work deals with the experimental investigation of the effect of addition of graphene nanoparticles in the cutting fluid under MQL on machinability characteristics such as tool flank wear, surface roughness and cutting zone temperature. Response surface methodology (RSM) was utilized for the experimental design. The concentration of graphene nanoparticles in the base fluid, cutting velocity, feed rate and depth of cut were taken as cutting parameters. Regression analyses was employed to estimate flank wear, surface roughness and cutting temperature. ANOVA was applied to examine the influence of cutting parameters on cutting temperature, flank wear and surface roughness. Results showed that higher concentration of graphene nanoparticles played a significant role in reducing flank wear of cutting tool even at higher magnitude of cutting velocity and feed rate which has an immense potential of boosting the productivity of machining process. Minimum surface roughness was also obtained at higher concentration of graphene nanoparticles along with higher magnitude of cutting velocity and lower magnitude of feed rate and depth of cut. In case of cutting zone temperature higher concentration of graphene platelets was effective in reducing cutting zone temperature along with lower magnitude of cutting velocity, feed rate and depth of cut. Finally, the optimization of output responses was done in order to provide the ranges for best cutting conditions.Today metal cutting is one of the most prominent operation in the production industry. Machining involves withdrawal of excess material from the workpiece by forcing of the cutting tool against the workpiece in order to obtain desired shape, size and surface finish of the workpiece. When ferrous materials are machined the cutting temperature increases with cutting velocity which results in softening of cutting tool leading to rapid wear and failure of the cutting tool (Bruni et al., 2006). Since high cutting speed is preferable for obtaining higher productivity so the generated heat has to be dissipated continuously around the cutting zone to maintain the sharpness of the cutting edge of the tool. If the temperature continues to rise then after a certain point of time tool becomes blunt

Materials Today: Proceedings, 2020

Hardened AISI 4340 alloy steel increments the cutting temperature during machining and is crucial output parameter for quality of machined part. Nano cooling mechanism is the burning issues in machining of hardened steel. More friction and temperature is generated during hard turning posing a difficulty in terms of tool span life. Controlling these tribological issues is the major challenges for accurate cutting. Significant improvement in the field of Nano assisted cooling can be applied in minimum quantity lubrication. Nano fluid is the colloidal suspension of Nano particles that is commercially available to the base conventional fluid was assessed to minimize the wear effect and friction to improve machinability. This Nano fluid is the heat transfer fluid representing as innovative machining fluid because of improved tribological and thermal characteristics. Motivated by this innovative concept, this review presents the significance of Nano fluid, various types of Nano fluids used throughout the hard material of AISI 4340 steel turning. At last, the concluding analysis with some future prospects have been has been pointed out. Moreover, this review analysis will provide the better answer to the manufacturing industry where the high strength low alloy steel is used using nano cutting fluid.

2014

Hardened steel AISI 4140 material is commonly used to produce automotive parts such as shafts, gears and bearings. Machining this material significantly increases the temperature in the cutting zone and is critical in deciding workpiece quality. Though cutting fluids are widely employed to dissipate the heat in machining, they threaten the ecology and health of workers. Hence, there arises a need to identify ecofriendly and user-friendly alternatives to conventional cutting fluids. Modern tribology has facilitated the use of a nano-lubrication system. For this purpose, a novel uses of nano-lubricants in minimum quantity lubrication (MQL) system were studied. In the present work, a mist of SiO 2 nano-lubrication was used and applied by air pressure in turning of hardened steel AISI4140. In this research work, the optimum SiO 2 nano-lubrication parameters to achieve correct lubrication conditions for the lowest tool wear and best surface quality were investigated. These parameters include nano-lubricant concentration, nozzle angle and air carrier pressure. The Taguchi optimization method is used with standard orthogonal array L 16 (4)3. This research is investigating on the new and novel uses of SiO 2 nano-lubricant by conducting analysis on tool wear and surface roughness using fuzzy logic and response analysis to determine which process parameters are statistically significant. Besides, these analyses were conducted in order to prove the effectiveness of nano-lubricant. Finally, confirmation tests were carried out to investigate optimization improvements.

Machining of materials has received substantial attention due to the increasing use of machining processes in various industrial applications. The research in this area is intended mainly to improve the machining of process so as to achieve the required surface quality. Machining processes, though employed widely as in metal removal process, have their own share of problems, such as high machining zone temperature, which may lead to poor surface quality. Machining fluids are applied in different forms to control such a high temperature, but they are partially effective within a narrow working range; recent studies also indicate their polluting nature. Solid lubricant assisted machining is a novel concept to control the machining zone temperature without polluting the environment. Solid lubricant, if employed properly, could control the machining zone temperature effectively by intensive removal of heat from the machining zone. A new experimental setup has been envisaged and built. Experiments have been carried out to study the effect of solid lubricant on surface finish and chip thickness. Results indicate that the effectiveness of solid lubricant is substantial through the experimental domains.