Minimum Quantity Lubrication System Research Articles

Hard Turning Performance Investigation of AISI D2 Steel under a Dual Nozzle MQL Environment

In recent years, hard turning has emerged as a burgeoning cutting technology for producing high-quality finishing of cylindrical-shaped hardened steel for a variety of industrial applications. Hard turning under dry cutting was not accepted because of the generation of higher cutting temperatures which accelerated tool wear and produced an inferior surface finish. Nowadays, minimum quantity lubrication (MQL) is widely accepted in hard turning to reduce the problems encountered in dry cutting. This research aimed to augment the MQL performance in the hard turning process of AISI D2 steel by applying a novel concept, namely, a dual jet nozzle MQL system that supplies the cutting fluid into the cutting zone from two different directions. The performances of hard turning are discussed using machinability indicator parameters, such as surface roughness, tool wear, cutting temperature, power consumption, noise emission, and chip morphology. The dual nozzle MQL greatly reduced the friction between contact surfaces in the cutting zone and provided improved surface quality (Ra = 0.448 to 1.265 µm). Furthermore, tool flank wear was found to be lower, in the range of 0.041 to 0.112 mm, with abrasion and adhesion being observed to be the main mode of wear mechanisms. The power consumption was greatly influenced by the depth of cut (46.69%), followed by cutting speed (40.76%) and feed (9.70%). The chip shapes were found to be helical, ribbon, and spiral c type, while the colors were a metallic, light blue, deep blue, and light golden.

분산상 모드를 이용한 1채널 최소 절삭유 가공 시스템의 미스트 포집 챔버 내 액화 현상 해석

The minimum quantity lubrication (MQL) system, which minimizes the use of a coolant, has recently been in the spotlight as a new machining system to overcome environmental problems. However the liquefaction of the oil mist at the collection chamber should be overcome. This study analyzes the oil mist liquefaction of the one-channel internal lubricant feed MQL system using computational fluid dynamics (CFD) and proposes the shape of the mist collection chamber that can reduce mist liquefaction. A discrete phase model (DPM) is used to simulate mist liquefaction, and the air and oil flow rates used in an actual MQL system are applied. After analyzing the reference model, a parametric study is conducted to derive the trend between the shape of the mist collection chamber and the liquefaction of the mist. The study results confirmed that the liquefaction can be reduced by changing the shape of the mist collection chamber.

Machinability improvement investigation in face milling of Ti–3Al–2.5V alloys using TiAlN coated carbide insert under dual nozzle minimum quantity lubrication cooling environment

This research presents the machinability analysis in face milling of Ti–3Al–2.5V alloys using TiAlN-coated carbide insert under dual nozzle minimum quantity lubrication (MQL) cooling conditions. The TiAlN-coated insert has several favorable characteristics like superior wear resistance, greater hardness, and high chemical stability at elevated temperatures. The performance capability of this cutting insert was assessed using machinability responses such as surface roughness, tool wear, and cutting temperature results. The improved quality finish was found with maximum Ra (0.823 µm) while the improved accuracy of flatness (0.044) was obtained even though the rotational speed of the face mill cutter ( N) was highest (1500 r/min). Likewise, an acceptable range of flank wear (0.058–0.118 mm) and a lower range of cutting temperature (65 °C–106.8 °C) was found due to the superior thermal characteristics of TiAlN coating, effective cooling, and lubricating capability of the dual nozzle MQL system in face milling to this alloy. Further, by using the entropy coupled multi-objective optimization ratio analysis method, the optimal value of milling parameters was computed as coolant flow rate ( Q) 50 ml/h, feed speed (vf) 200 mm/min, and rotational speed of the face mill cutter ( N) 500 r/min. At this optimal setting, the optimum Ra, VBc, and T were found as Ra = 0.596 µm; VBc = 0.058 mm, and T = 65 °C, respectively.

Investigation of non-edible vegetable oil as cutting fluid in boring operation using MQL technique for CEW-1 steel

The cutting fluid plays a significant role by cooling the machining region and evacuating chips from the cutting area during the machining. However, using the traditional cooling approach has a negative impact on human health and the environment. Furthermore, it contributes for 18 to 20 % of the entire production cost in the manufacturing industry. To address this problem, minimum quantity lubrication (MQL) is outperforming traditional cooling method in terms of achieving a high-quality surface and better overall machining performance. In this study a number of trials has been taken to investigate the effect of process parameters on surface finish, circularity, cylindricity. The trials have been carried out on boing machine. Comparative study by using Neem oil, Karanja oil and convectional oil in boring operation by using MQL technique has been carried out. Comparative results encourage using MQL system along with Neem and Karanja oil in boring operation of CEW-1 steel. Although kaanja oil and conventional cutting fluids perform similarly, Neem oil outperforms during boring of “CEW 1” Grade Steel. Also it has been observed from experimental results that minimum quantity lubrication method performed better as compare to conventional flood system.

Influence of Graphene Nanosheets on Thermo-Physical and Tribological Properties of Sustainable Cutting Fluids for MQL Application in Machining Processes

The growing need to increase productivity and pressures for more sustainable manufacturing processes lead to a shift to less harmful lubrication systems that are less harmful to nature and the people involved. The minimal quantity lubrication system (MQL) stands out in this respect, especially in interrupted cutting processes such as milling, due to the cutting interface’s highly dynamic and chaotic nature. Using graphene sheets in cutting fluids also increases the efficiency of machining processes. This work investigates the influence on thermophysical and tribological properties of concentrations of 0.05 wt% and 0.1 wt% of graphene sheets in two vegetable-based and one mineral-based cutting fluids. The fluids are first characterized (viscosity, thermal conductivity, diffusivity, and wettability) and tested in reciprocating and ramp milling tests; all experiments are based on norms. The results show that the experiments with cutting fluids (with and without graphene) showed better tribological behavior than those in dry conditions. The graphene sheets alter the thermo-physical and tribological properties of the cutting fluids. The MQL15 vegetable-based fluid showed better lubricating properties in the milling tests, with better conditions for tribosystem chip–tool–workpiece interfaces, which makes the friction coefficient, and wear rate stable. Vegetable-based cutting fluids, even in minimum quantities and with graphene nanoparticles, have a high potential for increasing the efficiency and sustainability of the milling process.

A review on the role of nanoparticles in MQL machining

The role of cutting fluid is significant for removing heat from machining zone, providing lubrication and chip removal process in the metal cutting operation. The green machining is achieved by using vegetable oil based minimum quantity lubrication (MQL) to reduce the environmental effect of cutting fluid. Adding nanoparticles on the base fluid of MQL system greatly improves the lubricating performance. In the current study, comprehensive review of various machining process under nanofluid MQL (NMQL) system has been discussed. To carry out the review, various studies on NMQL under four categories of machining process such as milling, grinding, turning and drilling in the recent four years have been considered. This article addresses the recent trends in the utilization of various nanoparticles and measuring the output performance parameters to the researchers on MQL system.

Thermo-physical, tribological and machining characteristics of Hastelloy C276 under sustainable cooling/lubrication conditions

Chemical reactivity and poor heat conductivity make nickel (Ni) and its alloys difficult to process. The aerospace industry's expectations for high-quality surfaces are one of the biggest hurdles in machining nickel components. Recent studies have found some flaws in mist lubrication techniques when utilised under high-speed cutting circumstances, thus nanoparticles with higher thermal conductivity than the base fluid is now being used in minimum quantity lubrication (MQL) systems. Nanocarbon dots (CDs) blended with bio lubricant is an effective coolant to enhance the heat transfer capability by decreasing friction. The inclusion of the right nanoparticle ratio to the base liquid is one of the most important challenges that arise when machining. This research focuses on a deeper exploration of Hastelloy C276's tribological behaviour and machinability under various cutting approaches (Dry, MQL Cryo CO2 and N-MQL). Milling trials were carried out with various speed-feed pairings and cutting conditions. Outcomes show that 0.8 wt% CDs with soybean oil reduces the surface roughness by 56–69 %, 15–24 %, and 15–26 % over dry, MQl and cryo CO2 environments. According to elemental study of cutting inserts, adhesion is the primary wear mechanism in all cutting mediums. Finally, the chillness produced by cryo CO2 has a positive effect compared to the N-MQL strategy by producing fine grains.

Effect of Eco‐Friendly Minimum Quantity Lubrication in Hard Machining of Vanadis 10: A High Strength Steel

Vanadis 10 SuperClean is a high vanadium alloyed powder metallurgy tool steel offering a unique combination of an excellent abrasive wear resistance in combination with a good chipping resistance. In this study, the effects of the eco‐friendly (100% biodegradable plant‐based) Minimum Quantity Lubrication (MQL) system on the cutting temperature, cutting tool vibration amplitude, tool wear, average surface roughness, and tool life in the turning of Vanadis 10 steel (50 HRC) used in the automotive industry are investigated. In the experiments, TiCN/Al2O3/TiN‐coated cemented carbide tools are used. Experimental results showed that, compared to Dry machining, MQL produced remarkable improvements in terms of cutting temperature, cutting tool vibration amplitude, tool wear, and surface roughness. In addition, the Taguchi experimental design, ANOVA, and linear and quadratic regression analyses are applied to the experimental data. The statistical analysis found the most effective parameter on average surface roughness to be the cutting environment (86.31%). It is determined that the cutting speed was the most effective on vibration amplitude and tool wear (46.22% and 32.41%). The correlation coefficients for the linear and quadratic regression analysis were 0.9 and 0.95, respectively.

A COMPREHENSIVE REVIEW ON MINIMUM QUANTITY LUBRICATION IN TURNING PROCESS

The physical health of human beings and the environment will be negatively influenced by the improper use of cutting fluid, which is an important factor for achieving sustainable machining. Turning is a basic process of all machining operations. Using a minimum quantity lubrication (MQL) system is the best way for achieving sustainable turning process. Improvements made in the MQL system to achieve better performance of the turning process have been discussed in this paper. Search categories that have been used to carry out the study are MQL system with the conventional cutting fluid, MQL system with nano-fluid, MQL system with cryogenics and restructured MQL system. The advancements in MQL turning process published over a span of four most recent years from 2018 to 2021 have been chosen for this review. In this study, the details of experimentation such as materials used for the workpiece, cutting tool materials, environments for lubrication, machining parameters, MQL fluids and performance parameters such as surface roughness, tool wear, cutting force, cutting temperature, etc. have been critically considered. Results investigated from various articles mostly show that advanced MQL systems such as MQL system with nano-fluid, MQL system with cryogenics and restructured MQL system are better than the conventional MQL system in terms of producing better output performance.

Minimum-Quantity Lubrication Systems with Additional Air Cleaning of the Grinding Wheel Surface

Minimum-Quantity Lubrication Systems with Additional Air Cleaning of the Grinding Wheel Surface

Thermophysical Investigations of Mango Seed Oil as a Novel Cutting Fluid: A Sustainable Approach Toward Waste to Value Addition

Abstract In the present work, a novel cutting fluid has been extracted from mango (Mangifera indica L.) seeds using the soxhlet technique. Cutting fluid from agricultural waste can reduce the shortage of edible oils and eliminate the need to dispose them. Therefore, nonedible oils are economically comparable with edible oils. In order to validate the effectiveness of extracted cutting fluid, thermophysical characterization and tribology tests were performed. The obtained results were compared with edible and nonedible oils, such as sunflower oil (SFO) and mahua seed oil (MaSO), respectively. Friction tests were conducted using a tribometer with pin-on-disk (WC-Co/Ti-3Al-2.5V) at different tribological conditions. The worn surface and wear mechanism of disks were examined using a scanning electron microscope (SEM) associated with energy-dispersive spectroscopy (EDS) for comparing the elemental composition quantitatively. These findings showed that mango seed oil (MSO) exhibited the lowest coefficient of friction (COF) and wear volume followed by MaSO, SFO, and dry, respectively. SEM analysis showed that no plowing was observed; however, small pits and cracks were found on wear track under MSO. Further, the abovementioned oils were used as a cutting fluid in the machining of Ti-3Al-2.5V (grade 9 alloy). In this regard, MSO has shown a similar effect in turning operation with minimum quantity lubrication (MQL) system.

Investigation and Optimization of MQL System Parameters in the Roller-Burnishing Process of Hardened Steel

In the current study, the internal burnishing process under the minimum quantity lubrication (MQL) condition has been optimized to decrease the cylindricity (CYL) and circularity (CIC) of the burnished hole, while the surface roughness (SR) is predefined as a constraint. The optimizing inputs are the diameter of the spray nozzle (D), the spray elevation angle (A), the lubricant quantity (Q), and the pressure value of the compressed air (P). The artificial neural network (ANN) models of burnishing performances are proposed to optimise inputs. The grey relational analysis (GRA) is utilized to compute the weight value of each response. Optimal values of MQL system parameters and technological objectives are selected with the aid of an evolution algorithm (vibration and communication particle swarm optimization (VCPSO) algorithm). The results indicated that the optimal outcomes of the D, A, Q, and P are 1.5 mm, 50 deg, 140 ml/h, and 0.6 MPa, respectively. Furthermore, the CYL, CIC, and SR were decreased by 53.14 %, 57.83 %, and 72.97 %, respectively, at the optimal solution. Finally, the obtained results are expected to be a significant solution to support the machine operator in selecting the optimal MQL system parameters to improve the hole quality in the MQL-assisted burnishing process.

A numerical study on the influence of minimum quantity lubrication parameters on spray characteristics of rapeseed oil as cutting fluid

PurposeThis paper aims to analyze spray characteristics of rapeseed oil as a cutting fluid in minimum quantity lubrication (MQL) through numerical simulation.Design/methodology/approachComputational fluid dynamics (CFD) is used in this numerical study. The Eulerian–Lagrangian approach was used in this simulation to project trajectories of the droplets as the cutting fluid is dispersed into a continuous phase, i.e. air. The spray characteristics of the multiphase fluids were obtained numerically using the discrete phase model (DPM).FindingsThe spray characteristics such as particle diameter and velocity were obtained for various pressure level, flow rate and nozzle diameter. The particle diameter decreased with increased pressure, whereas the velocity increased with increased pressure, flow rate and nozzle diameter. The changes in particle diameter are insignificant with respect to flow rate and nozzle diameter. DPM is an effective tool for machining processes to determine the behaviour of different cutting fluids under the MQL system.Originality/valueIn this study, the droplet and velocity distribution of vegetable oil, i.e. rapeseed oil, was investigated at the different air pressure, flow rate and nozzle diameter. This study will give insight for the manufacturer to select the better MQL system parameters to reduce the cost, time of machining processes and enhance the sustainability of the process.

Optimization of surface qualities in face milling of EN-31 employing hBN nanoparticles-based minimum quantity lubrication

EN-31 steel is used for making moulding dies, bearings, and other automobile parts which are subjected to heavy wear and tear. The main requirements in such applications are the high surface finish and good surface microhardness. However, controlling the machining variables for one of these characteristics doesn’t ensure good results for the other one. Thus, it became essential to execute multi-response optimization to determine the ideal parametric setting for both characteristics. In the current study, the Grey Relational Analysis (GRA) is used for concurrent optimization of surface roughness and surface microhardness while face milling of EN-31 by employing nano-particle-based minimum quantity lubrication (MQL). The nanohBN (Hexagonal Boron Nitride) nanoparticles are mixed in lubricating oil to enhance the lubricating and cooling effects of the MQL system. The ideal parametric combination for the multi-response factor is obtained as a lubricant flow rate of 100 ml/hr, Spraying distance of 40 mm, and hBNnano-particles weight concentration of 1 % in lubricating oil. All MQL variables have shown a significant impact on the multi-response factor. The lubricant flow rate has shown the highest significance for the multi-response factor with a contribution of 58.1 %.

A comprehensive study on minimum quantity lubrication

The cutting fluid plays a significant role by cooling the surface of tool, substrate and removing chips from the cutting area during metal machining operations (turning, milling, grinding etc.). However, by adopting the conventional method of cooling (flood cooling), it affects the human health and the environment badly. In addition, it accounts for 16–20% of the total cost of manufacturing in the production industry. To overcome this issue, minimum quantity lubrication (MQL) is gaining higher potential for attaining good quality surface and improved overall performance of machining than conventional cooling methods. Because MQL system reduce the use of coolant by depositing the suitable mixture of cutting fluid and compressed air during machining in optimum quantity. In general the amount of cutting fluid in MQL system is in ml/hr instead of in l/min as in flood cooling. Beside these benefits of MQL system, it also decreases the cutting forces, tool wear, temperature and friction during machining. Hence the aim of this paper is to provide an overview of MQL system, cutting fluids and effect of MQL on the machining performance during turning operation. The study revealed that by employing MQL system in turning results in significant enhancement in metal removal rate and surface finish by 30% and reduced cutting force (by 17.07–40%), cutting temperature (by 6.72–10%), tool wear and eliminated built up edge. Overall this improved the overall performance of the machining.

Development of a Low Cost Eco-Friendly Minimum Quantity Lubrication System for Machining Processes

Recently all environmental worries are calling for reducing the usage of fluids in machining operations. One of the promising solutions that appeared lately is minimum quantity lubrication (MQL). This research aimed to develop an eco-friendly cooling system for a lathe machine and assess its performance. After considering the customer needs, the needs were translated into engineering specifications in the conceptual design phase, and then the quality function deployment was developed. Three concepts were generated and evaluated considering the selection criteria, and a final concept was selected using the decision matrix method. Following this, a detailed design and fabrication of the sub-systems such as the oil tank and a structure accommodate all the components. The developed system was tested on six different workpiece samples to compare the MQL system with the conventional one. In general, the MQL system resulted in lower surface roughness values as well as lower tool wear.

Thermophysical, tribological, and machinability characteristics of newly developed sustainable hybrid lubri-coolants for milling Ti-6Al-4V

Burgeoning demand for machinability, health, and ecology, Environmental Protection Agency (EPA) regulations are pushing the modern manufacturing sector to apply dry or biodegradable cutting fluids, which are insufficient in the machining of difficult-to-cut materials. Therefore, this study is devoted to proposing a newly developed hybrid ethanol-ester oil lubri-coolant for machining titanium alloy. To encompass the effectiveness of the proposed cutting medium, the thermophysical properties (density, thermal conductivity, viscosity, specific heat), and tribological properties (friction coefficient, friction force), and investigated. Besides, the machinability performance of hybrid lubri-coolant is determined in terms of cutting temperature, cutting force, surface roughness, residual stresses, tool wear through minimum quantity lubrication (MQL) system in the high-speed machining of heat-treated Ti-6Al-4V. The machinability performance of hybrid lubri-coolant are compared to dry cuttings. Findings have depicted that density, viscosity, and thermal conductivity were decreased with the increase of temperature while specific heat was increased with the increase of temperature. Tribological characteristics showed the highest friction coefficient and friction force under dry conditions while minimum under hybrid ethanol-ester oil (1:1) conditions. The hybrid ethanol-ester oil lubri-cooling in milling showed lower cutting temperature, cutting force, surface roughness, residual stresses, and minimum tool wear results. The hybrid ethanol-ester oil is biodegradable, providing efficient cooling with the evaporation of ethanol, and lubrication due to long-chain ester oil molecules. The polar nature of ethanol and ester oil prevented microparticles adhesion and made a tribo-film on the tool-workpiece and prevented rubbing or frictional heat generation.

Research of multi-response optimization of milling process of hardened S50C steel using minimum quantity lubrication of Vietnamese peanut oil

This study aims to build a regression model when surveying the milling process on S50C steel using Minimum Quantity Lubrication (MQL) of Vietnamese peanut oil-based on Response Surface Methodology. The paper analyses and evaluates the effect of cutting parameters, flow rates, and pressures in minimum quantity lubrication system on cutting force and surface roughness in the milling process of S50C carbon steel materials after heat treatment (reaching a hardness of 52 HRC). The Taguchi method, one of the most effective experimental planning methods nowadays, is used in this study. The statistical analysis software, namely Minitab 19, is utilized to build a regression model between parameters of the cutting process, flow rates and pressures of the minimum quantity lubrication system and the cutting force, surface roughness of the part when machining on a 5-axis CNC milling machine. Thereby analyzing and predicting the effect of cutting parameters and minimum quantity lubrication conditions on the surface roughness and cutting force during machining to determine the influence level them. In this work, the regression models of Ra and F were achieved by using the optimizer tool in Minitab 19. Moreover, the multi-response optimization problem was solved. The optimum cutting parameters and lubricating conditions are as follows: Cutting velocity Vc=190.909 m/min, feed rate fz=0.02 mm/tooth, axial depth of cut ap=0.1 and nozzle pressure P=5.596 MPa, flow rate Q=108.887 ml/h. The output parameters obtained from the above parameters are Ra=0.0586 and F=162.035 N, respectively. This result not only provides the foundation for future research but also contributes reference data for the machining process

The Effects of MQL and Dry Environments on Tool Wear, Cutting Temperature, and Power Consumption during End Milling of AISI 1040 Steel

Minimum quantity lubrication (MQL) is a sustainable method that has been efficiently applied to achieve machinability improvements with various materials in recent years, such as hardened steels, superalloys, soft metals, and composites. This study is the first to focus on the performance evaluation of MQL and dry milling environments with AISI 1040 steel. The tool wear, cutting temperature, and power consumption were considered as the quality responses while cutting speed, feed rate and machining environment are taken as input parameters. The effects of the influential factors are analyzed using analysis of variance (ANOVA) and bar charts. Additionally, Taguchi signal-to-noise (S/N) ratios are utilized in order to determine the optimum parameters for the best quality responses. The results show that the MQL system provides better performance compared to dry milling by reducing the tool wear, cutting temperature, and power consumption. According to the ANOVA results, the cutting environment affects the cutting temperature (37%) and power consumption (94%), while cutting speed has importance effects on the tool wear (74%). A lower cutting speed (100 m/min) and feed rate (0.10 mm/rev) should be selected under MQL conditions to ensure minimum tool wear and power consumption; however, a higher feed rate (0.15 mm/rev) needs to be selected along with a low cutting speed and MQL conditions to ensure better temperatures. A comparative evaluation is carried out on the tool wear, cutting temperature, and power consumption under MQL and dry environments. This investigation is expected to contribute to the current literature, highlighting the superiority of sustainable methods in the milling of industrially important materials.

Experimental investigation to study the effect of synthesized and characterized monotype and hybrid nanofluids in minimum quantity lubrication assisted turning of bearing steel

A minimum quantity lubrication system using biodegradable cutting fluids has facilitated the excellent machining performance and is observed as more sustainable. In the view of enhancement of machining performance, the utilization of nanofluids with a minimum quantity lubrication system as a cutting fluid delivered noteworthy outcomes. For the present experimental investigation, the monotype nanofluids (copper oxide and zinc oxide) and a hybrid nanofluid (copper oxide/zinc oxide) were synthesized by using a two-step method. Scanning electron microscopy and energy dispersive X-ray analysis were performed to characterize the synthesized nanoparticles. A vegetable oil was utilized as a base fluid and three types of nanofluids were prepared by the addition of a surfactant (butenol). Also, ultrasonication has been performed to avoid the agglomeration of nanoparticles into the base fluid. The thermal conductivity evaluation of prepared nanofluids was carried out by using a hot wire method. The effects of three nanofluids were investigated by considering three machining input variables (cutting speed, feed rate and depth of cut) on response variables (surface roughness and cutting zone temperature) during bearing steel turning under nanofluid minimum quantity lubrication cooling conditions. The multi-objective optimization was performed by using grey relational analysis and found that the hybrid nanofluid (copper oxide/zinc oxide) was noted as the highly effective cooling condition as equated to copper oxide and zinc oxide monotype nanofluid. The hybrid nanofluid (copper oxide/zinc oxide) shows a 65% and 60% reduction in surface roughness on comparing with copper oxide and zinc oxide nanofluids, respectively. Also, the minimization of cutting zone temperature was observed under the hybrid nanofluid (copper oxide/zinc oxide) by 11% and 13% on equating with copper oxide and zinc oxide nanofluids, respectively.