Conventional Flood Lubrication Research Articles

Flank Surface Treatment of Spur Gears Machined by MQL Assisted Hobbing Using Micro-Plasma Transferred Arc

In the present study, feasibility of micro-plasma transferred arc (M-PTA) for flank surface treatment of gears has been explored. 20MnCr5 spur gears manufactured by sustainable technique minimum quantity lubrication assisted hobbing (MQLAH) were subjected to M-PTA-based heat treatment for further improving the surface properties of flank surface and comparisons were made with respect to M-PTA treated gears machined by conventional flood lubrication assisted hobbing (FLAH). The results revealed that M-PTA enhanced flank surface hardness of all the gears without deteriorating the gear accuracy. However, flank hardness increment was observed to be almost 18% in case of MQLAH gears as compared to 15% for FLAH gears. This study proves that M-PTA based heat treatment after MQLAHcan result in superior surface hardness along with better gear accuracy and can improve the sustainability of overall process chain involved in machining-based gear manufacturing.

Study on machining performance in grinding of Ni-base single crystal superalloy DD5

The Ni-base single crystal superalloy DD5 is commonly employed in critical parts of turbine blades and turbine disks in aeronautical engines. To improve the surface machining quality, single-factor experiments were carried out to investigate the changes of grinding force, surface morphology, and chip morphology under different grinding conditions (dry, conventional flood, minimum quantity lubrication). The experiments showed that the conventional flood lubrication and minimum quantity lubrication (MQL) could enormously reduce the surface roughness, grinding force, and work-hardened layer thickness of DD5. At the depth of 5 ~ 15 μm, the DD5 subsurface microhardness decreased sharply with the increase of depth, and the microhardness under different grinding conditions was in the order of dry grinding, conventional flood, and MQL. However, at the depth of 20 ~ 150 μm, the DD5 subsurface microhardness tended to equilibrate and fluctuate around 540 HV. In addition, compared with dry grinding, the degree of chip serration was obvious in flood or MQL environment, and its chip formation frequency fluctuated less and chip formation was stable. Within the experimental parameters, the MQL grinding machining method obtained the lowest surface roughness and the highest surface quality with the lowest associated cost, which is the ideal grinding and cooling lubrication method for the Ni-base single crystal superalloy.

Evaluating the effect of minimum quantity lubrication during hard turning of AISI D3 steel using vegetable oil enriched with nano-additives

Conventional flood lubrication techniques have serious impacts on the environment, health, and economy. Thus, the implementation of advanced lubrication techniques such as minimum quantity lubrication (MQL) has gained attraction worldwide as a reliable alternative to flood lubrication due to its effectiveness and eco-friendly characteristics. In order to increase the efficiency of MQL, nanoparticles have recently been added to the base fluids to improve the performance of lubrication thanks to their thermo-physical properties. In this work, an eco-friendly vegetable oil called rice bran oil (RBO) was used as a lubrication fluid with and without the addition of zinc oxide (ZnO) nanoparticles in order to investigate their influence on the turning performance characteristics, in terms of cutting force, surface roughness, flank wear and cutting temperature, during hard turning of AISI D3 steel. Taguchi L16 orthogonal array was implemented to investigate the effect of turning parameters including cutting speed, feed rate, and depth of cut on the response variables. The results showed that ZnO nanoparticles-enriched base fluid gives better performance than machining with a pure oil in terms of mitigating the severity of cutting force by about 10.68–18.48%, reducing tool wear by about 9.33–51.96%, and reducing the roughness of the machined surface by 3.86–12.84%.

The Emergence of MQL with vegetable oil as a green manufacturing technique: A Review

For every manufacturing industry, product rejection is not tolerable. Productivity suffers because of rejection, material cost, and labor cost increases. Cutting fluids are used to protect the tool and work-piecework-piece from the damaging effects of high temperatures and poor surface finishes. Cutting fluids are used as lubricating and cooling agents. Due to cost constraints, most small-scale industries in developing nations employ conventional flood lubrication systems, resulting in increased exposure to dangerous chemicals and environmental issues. As a result of increased health concerns and rigorous government regulations, innovative methods to decrease or remove harmful cutting fluid have been developed. In this review paper, three approaches are considered while surveying the literature. Hazardous effects of the cutting fluids; comparison of dry, flood, and MQL cutting; and performance of the cutting fluids prepared using vegetable oil. It is found that vegetable oil with minimum quantity lubrication under different machining conditions gives better performance and reduces health hazards.

Performance and mechanism evaluation during milling of CFRP laminates under cryogenic-based conditions

Due to the hygroscopicity of CFRP, dry and/or near-dry cutting conditions instead of conventional flood lubrication is recommended for CFRP machining. However, thermal damage, poor surface integrity, and harmful dust occur when machining CFRP under dry conditions. To address the above problems, this paper aims to investigate the machining performance of CFRP laminates under cryogenic-based conditions, which are characterized as cryogenic supercritical carbon dioxide (scCO2) and vegetable oil-based cryogenic minimum quantity lubrication (CMQL). The milling temperatures, milling forces, surface quality and surface generation mechanism were particularly studied to analyze the effect of cooling category on the milling performance of CFRP under varying cutting parameters. To reveal the underlying mechanisms of performance evolution with different lubri-cooling conditions, the basal tribology and wettability tests were innovatively carried out as a function of lubri-cooling environments. Results indicate that the minimum milling forces, milling temperatures and machined surface roughness were obtained under CMQL condition. Cryogenic cutting operation reduces the cutting temperature, increases the cutting force while improves the surface quality. The mechanism of material removal is significantly different under different tool-fiber angles. This study also demonstrated the feasibility of cryogenic cutting, especially CMQL condition to improve the surface quality during CFRP precision machining.

Effect of Minimum Quantity Lubrication System for Improving Surface Roughness in Turning Operation

Due to increase in temperature at the cutting zone, the tool wear and surface roughness along with the non-uniform chip formation and the dimensional deviation of the job by using the conventional cutting fluid, the machining operation experts have directed their concentrations in order to achieve a smooth machining operation by using minimum quantity lubrication (MQL). As a consequence, numerous efforts can be seen for not only having the optimum cutting parameters but also other parameters that enhance the product quality and the surface roughness. In this regard, relevant experimental and numerical data outcomes not only MQL but also conventional cutting fluid (CCF) in the turning operation of 50HRC steel has been investigated experimentally. It is revealed that the surface roughness becomes optimal and significantly reduced for the condition of MQL with that of dry and conventional flood lubrication.

Application of Minimum Quantity Lubrication for Various Machining Processes – A Mini Review

Minimum Quantity Lubrication (MQL) is a great alternative lubricating and cooling environment method that has been widely used to replace the conventional flood coolant which brings drawbacks involving environmental awareness, human’s safety and health and manufacturing cost. Taking into account the recent trends, this review paper describes a summary of the research journals reviewed previously MQL in various machining operations involving milling, turning, drilling and grinding of various types of materials. Most recent papers have described the use of vegetable oils which helps in maintaining the environmentally friendly machining. Also, the aided of nanofluid particles and hybrid environment in MQL application conversed the outstanding efficiency in machining performances as compared to that conventional flood lubrication technology. Briefly, this paper have shown the proficiency of eco-friendly MQL approach in improving the performance of machinability such as reducing the surface roughness of workpiece, producing a higher rate of tool life and also reducing the cutting temperature that leads to a sustainable machining environment in the future work.

Predictive modelling and parametric optimization of minimum quantity lubrication–assisted hobbing process

This paper focuses on parametric analysis, modelling, and parametric optimization of minimum quantity lubrication–assisted hobbing (MQLAH) using an environment-friendly lubricant for manufacturing superior quality spur gears. Influences of hob cutter speed, axial feed, lubricant flow rate, air pressure, and nozzle angle on the deviations in total profile, total lead, total pitch and radial runout, and flank surface roughness parameters were studied by conducting 46 experiments using the Box-Behnken method of response surface methodology. Results revealed that the effect of air pressure is negligible but other parameters have a significant impact on the considered responses. A back propagation neural network (BPNN) model was developed to predict microgeometry deviations and flank surface roughness values of the MQLAH-manufactured spur gears. The BPNN-predicted results are found to be very closely agreeing with the corresponding experimental results with a mean square error as 0.0063. A real-coded genetic algorithm (RCGA) was used for parametric optimization of MQLAH process for simultaneous minimization of microgeometry deviations and flank surface roughness. Standardized values of the optimized parameters were used to conduct confirmation experiments whose results had very good closeness with RCGA-computed and BPNN-predicted values and produced spur gears of superior quality. This study proves MQLAH to be a potential sustainable replacement of conventional flood lubrication–assisted hobbing for manufacturing cylindrical gears of better quality.

An outlook on the sustainable machining aspects of minimum quantity lubrication during processing of difficult to cut materials

Modern machining scenario is facing intense pressure to adopt sustainable machining to fulfill the demand of future energy need without compromising the reserve of conventional energy resources. The water crisis, energy deficit, global warming and profitability have generated the need of handsome debate on sustainable manufacturing in present scenario of industry 4.0. The technological development have raised the comfort level of living being with context to transportation, telecommunication and medical facilities as a result of processing harder grade materials utilizing conventional and modern machining operations. However, during processing of aforementioned materials the advanced level of process parameters require higher energy, consequently, resulted into elevated cutting temperature leading to poor product quality as well as uneconomical machining. Hence to lower the excessive cutting temperature the metal working fluids are utilized to absorb the heat evolved at different zones of machining operation. Consequently, the temperature get reduced, but raises the scarcity of negative effects such as skin rashes, itching, asthma, water pollution, soil pollution, mist generation and sometimes unprofitable conditions. So, to bridge the gap between the limitations of dry machining and conventional flood lubrication, the concept of minimum quantity lubrication has been exercised to achieve the challenges and goals of sustainable machining. In this papers, the sustainable machining aspects of minimum quantity lubrication has been while processing the titanium, Inconel, magnesium and other ferrous alloys which are widely used. The Investigation indicated that the sustainable machining is dominant in present era of machining employing minimum quantity lubrication, cryogenic cooling and other hybrid cooling methodologies. Furthermore, several technological advancements, such as UAG, ECT, UAM and LAM have been reported to ease conventional machining operations during processing of harder grades materials.

Sustainability Assessment of Advanced Machining Technologies

Efficient cooling and lubrication techniques are required to obtain sustainable machining of difficult-to-cut materials, which are the pillars of aerospace, automotive, medical and nuclear industries. Cryogenic machining with the assistance of lubricated Liquid Carbon Dioxide (LCO2) is a novel approach for sustainable manufacturing without the use of harmful water-based metalworking fluids (MWFs). In case of unavoidable use of MWFs under high pressure, such as turning finishing processes of difficult-to-cut materials, the pulsating high pressure delivery of MWFs prolongs the tool life and enables the control over chip length to prevent surface damage of high value-added parts. In this paper, sustainability assessment of both advanced principles was carried out, considering overall costs and operational safety. Experimental tests were executed on difficult-to-cut materials in comparison to conventional flood lubrication. For both techniques, longer tool life compared to flood lubrication was observed additional cleaner production and higher part quality led to reduced long-term overall costs. These advanced machining technologies are also operation safe, proving to be a sustainable alternative to conventional machining.

Comparative study on the performance of the MQL nanolubricant and conventional flood lubrication techniques during grinding of Si3N4 ceramic

Silicon nitride (Si3N4) ceramic is highly desired in various engineering applications due to its exceptional properties. However, machining the Si3N4 ceramic suffers setbacks due to various degrees of damage inflicted on the ceramic during machining. Studies have shown that the minimum quantity lubrication (MQL) process is a better alternative to the flood cooling lubrication system during grinding of advanced engineering ceramics. The MQL technique is a highly efficient and eco-friendly lubrication method that can be used to reduce the different types of surface and subsurface damages, while significantly lowering the consumed lubricant. In this work, the performance of the MQL and flood cooling lubrication techniques during grinding of Si3N4 ceramic was investigated. The MQL nanolubricant was formed by suspending silicon dioxide (SiO2) nanoparticles in environmentally friendly vegetable oil (canola oil). Also, the effect of the input parameters, i.e., feed rate, depth of cut, type of diamond wheel, and lubrication type, were investigated on the output parameters, i.e., grinding forces, workpiece surface roughness, surface damages, and wheel wear. The Taguchi mixed-level parameter experimental design (L16) was used in the design of the experiment, and the signal-to-noise ratio was used to optimize the grinding process. Furthermore, the adaptive neuro-fuzzy inference system (ANFIS) prediction method was used to predict and analyze the variation of the input parameters with the grinding forces and surface roughness. Validation experiments also indicate that the ANFIS models for the normal grinding force, tangential grinding force, and surface roughness have accuracies of 98.45, 98.58, and 96.31%, respectively.

Experimental study of non edible vegetable oil as a cutting fluid in machining of M2 Steel using MQL

Machining with conventional flood lubrication system is a general practice in the manufacturing industries for reducing friction, heat and cutting power. The type of cutting fluid used during machining play important role in enhancing the machining performance if and only if it is selected, applied, handled and disposed in proper way. The research aimed to evaluate the performance of aloe vera oil as a cutting fluid in machining of M2 Steel, carbide cutting tool insert was used as a cutting tool under different machining parameters with different types of cutting fluids such as aloe vera oil and conventional cutting fluid in machining. The performance of developed cutting fluid is compared with conventional cutting fluid. The results of surface roughness obtained during Turning of M2 Steel with Minimum quantity lubrication of both mineral oil and vegetable are compared with each other and it is observed that the surface roughness of non edible vegetable oil i.e. alove vera give better surface finish compared with mineral oil also improved performance in terms of tool wear found while comparing alove vera oil with conventional cutting fluid.

EXPERIMENTAL INVESTIGATIONS OF VEGETABLE & MINERAL OIL PERFORMANCE DURING MACHINING OF EN-31 STEEL WITH MINIMUM QUANTITY LUBRICATION

Machining with Conventional flood lubrication is a common practice in the industries for reducing friction, heat and cutting power. The type of cutting fluid used during machining play important role in enhancing the machining performance if and only if it is selected, applied, handled and disposed in better way. Cutting fluids often poses hazard to man, environment, machine and material. It sometimes also becomes uneconomical; when application method, flow rate and cost of cutting fluid are remain unattended or underestimated. In Conventional flood lubrication a large quantity of lubricant is applied continuously at the tool chip interface does not remove heat effectively as much required because of poor penetration and obstruction from the chip. Therefore this system is becoming uneconomical for machining and unsuitable for environment. On the other hand wastage disposal of this large quantity of cutting fluid (petroleum based) is becoming problematic. Therefore the present study has been conducted by Vegetable based Minimum quantity Lubrication to reduce or to minimize hazards caused by Conventional flood lubrication. The Results of surface roughness obtained during Turning of EN-31 Steel with Minimum quantity lubrication of both mineral oil and vegetable are compared with each other and indicates that the surface roughness of vegetable oil is close proximity with mineral oil. Index Terms: Minimum quantity lubrication (MQL), Vegetable oil, Mineral oil, Surface roughness, EN-31 Steel

IMPACT OF VARYING THE NOZZLE STAND - OFF DISTANCE ON CUTTING TEMPERATURE IN TURNING OF EN-31 STEEL WITH MINIMUM QUANTITY LUBRICATION

Tool wear is a natural phenomenon in all metal cutting operations due to high friction at tool work interface, which affect the tool life, product quality and accuracy of work. For minimizing the friction at tool work interface the cutting fluids or lubricants are used for cooling and lubrication, hence improvement in machining efficiency. But if the quantity and quality of lubricants are unattended or underestimated then it creates problems like soil, water, environmental pollution and also makes the machining process uneconomical. The different cooling and lubrication techniques have been developed today. So it is necessity of present day scenario of machining to work with technology which would not degrade the environment, face the competition and have better quality of products. Different research shows that conventional Flood lubrication is limited by health hazards, misting and sometime uneconomical as compared to other techniques, due to its high discharge rate of fluid. These problems have been overcome by using dry machining. Studies shows that dry machining also becomes non efficient and uneconomical during cutting of harder materials at higher cutting speed, feed and depth of cut, although it is environmental friendly and economical at particular machining level. So to minimize all these Problems of health hazards, non-economy, intense tool wear in case of flood cooling and dry machining, the minimum quantity lubrication (MQL) has been applied in this present research. The effect of varying the nozzle stand-off distance and lubricant pressure have been considered in this study, to find out the best results in terms of cutting temperature. The experimentation has been conducted during turning of EN- 31 Alloy Steel with minimum quantity lubrication at flow rate of 150 ml/hr having vegetable based oil. The temperature has been measured by K- type thermocouple .The vegetable oil has been selected due to its environmental friendly behavior and does not produce health hazards, like mineral oil during flood lubrication. Index Terms: Tool wear, Flood lubrication, Dry machining, Minimum quantity lubrication, Nozzle stand-off distance

Application of Taguchi method to selection of optimal lubrication and cutting conditions in face milling of AlMg 3

This paper outlines the Taguchi optimization methodology, which is applied to optimize the cutting parameters in face milling when machining AlMg 3 (EN AW 5754) with HSS (high speed steel) tool under semi-finishing conditions in order to get the best surface roughness and the minimum power consumption. Beside the conventional flood lubrication, the investigations include the minimal quantity lubrication and the dry milling. These environment-friendly cutting techniques are considered two practical ways to the cleaner manufacturing in the context of the sustainable production. The parameters evaluated are the cutting speed, the depth of cut, the feed rate and the cooling lubrication techniques (cutting fluid flow). The appropriate orthogonal array, signal to noise (S/N) ratio and Pareto analysis of variance (ANOVA) are employed to analyze the effect of the mentioned parameters on the good surface finish (surface roughness). This paper illustrates the application of the techniques for single performance characteristics optimization, which employs the weighting factors to each of the S/N ration of the responses to obtain a multi-response S/N ratio for each trial of the orthogonal array and, finally, a single optimal process parameters setting. Using Taguchi method for the design of experiments (DOE), it is investigated the significant influence and the parameters interaction effect with minimum number of trials as compared with a full factorial design.

An Experimental Study of Static and Dynamic Characteristics of a 580mm(22.8in.) Diameter Direct Lubrication Tilting Pad Journal Bearing

Abstract Direct lubrication tilting pad journal bearings (DLTPJ bearings) have rarely been applied to large-scale rotating machinery, such as turbines or generators, whose journal diameters are more than 500mm. In this paper, static and dynamic characteristics of a 580mm(22.8in.) diameter DLTPJ bearing were studied experimentally using a full-scale bearing test rig. In the static test, distribution of metal temperature, oil film pressure, and bearing loss were measured in changing oil flow rate, with mean bearing pressure ranging up to 2.9MPa. The maximum metal temperature of the DLTPJ bearing was compared to that of a conventional flood lubrication bearing, and it was confirmed that the direct lubrication could increase load capacity. In the dynamic test, spring and damping coefficients of oil film were obtained by exciting the bearing casing that was floated by air bellows. These data will be used for analysis and design of steam turbine rotors and their bearing systems. Also, vibration of pads was investigated because metal failure on upper pads due to vibration has been found in some actual machines. In order to generate oil film pressure on the surface of upper pads, a Rayleigh-step was machined there, and it was confirmed that vibration was reduced by the Rayleigh-step.