Minimum Quantity Lubrication Flow Research Articles

Evaluation of Surface Quality and Productivity in Conventional Milling of Copper Beryllium Using Minimum Quantity Lubrication

Copper Beryllium (C17200) has ideal physical and mechanical properties of high fatigue strength, thermal conductivity, and hardness, making the alloy ideal for various high-reliability applications in aerospace, producing inserts and tooling for hazardous environments. However, surface quality and productivity challenges are prominent when processing the alloy due to its properties. This study evaluates the surface quality and productivity in end-milling of Copper Beryllium by analyzing the effects of feed rate, minimum quantity lubrication (MQL) flow rate, and cutting depth on surface roughness (Ra) and material removal rate (MRR). The experiment was designed using the Box-Behnken design, and the samples were machined on a CNC milling machine. The results showed that the MQL flow rate was significant to surface roughness, while the cutting depth was significant to MRR. The optimum parameters were determined as a feed rate of – 60 mm/min, an MQL flow rate of – 80 ml/hr., and a cutting depth of – 0.511 mm, which yielded a surface roughness of 0.12 µm and MRR of 10.19 g/min. The study's novelty is that it considers MQL flow using vegetable oil-based cutting fluid (CF) as an input parameter in machining, offering insight into eco-friendly and cost-effective machining practices. Finally, the significance of the study lies in investigating the machinability of Cu-Be alloy material, addressing challenges related to surface quality and productivity during milling operation.

Enhancing high-speed CNC milling performance of Ti6Al4V alloy through the application of ZnO-Ag hybrid nanofluids

Abstract This research investigates the performance of high-speed CNC milling operations on Ti6Al4V alloy by employing a novel ZnO-Ag hybrid nanofluid. The study involves the preparation and characterization of nanofluids with varying concentrations of nanoparticles, focusing on thermal conductivity and stability. The machining experiments encompass four critical input parameters: Minimum Quantity Lubrication (MQL) flow rate, cutting speed, nanofluid concentration, and feed rate. Performance evaluation is based on average surface roughness (Ra) and cutting temperature. Key findings include a remarkable 21.05% improvement in thermal conductivity for the ZnO-Ag-based sunflower oil at 0.2% volume concentration compared to 0.05% concentration. The prepared nanofluids exhibit good stability. Moreover, cutting speed and MQL flow rate emerge as significant contributors to Ra, accounting for 35.62% and 34.82%, respectively. Interestingly, MQL flow rate is identified as the most influential factor, surpassing even cutting speed. SEM images for tool wear reveals that the ZnO-Ag based sunflower oil reduced tool wear significantly. In conclusion, the proposed ZnO-Ag-based sunflower oil at 0.2% concentration emerges as the good option for sustainable high-speed machining of Ti6Al4V alloy, showcasing

Influence of singular and dual MQL nozzles on sustainable milling of Al6061-T651 in different machining environments

Al6061-T651 alloy is widely used in the aerospace industry due to its superior properties and is a very difficult-to-cut material with high quality because of tool wear and thermal softening. This situation causes low surface quality, high cutting force, and limited tool life, as well as an increase in total consumed energy, total carbon dioxide emission, and total machining cost. Therefore, it is necessary to sustainably increase this aerospace alloy's machining performance. In the presented study, for the first time, milling performance and sustainability assessment of Al6061-T651 alloy under dry, minimum quantity lubrication (MQL), nano molybdenum disulfide (MoS2) reinforced nanofluid-assisted MQL (N-MQL) cutting conditions were investigated using the single nozzle and dual nozzles, two different MQL flow rates, and three different cutting speeds. In this context, the results of surface roughness, cutting force, feed force, cutting tool flank wear, total consumed energy, total carbon emission, and total machining cost were obtained. As the cutting speed increased, the cutting force, feed force, total consumed energy, total machining cost, and total carbon emission decreased by 12.9 %, 18 %, 7.8 %, 6 %, and 0.1 %, while the surface roughness increased by 34.9 %. In the MQL and MoS2 N-MQL cutting conditions at the same flow rate, using dual nozzles instead of a single nozzle improved machining response and sustainability indicators. In addition, increasing the flow rate improved machining performance and sustainability indicators. Using the double nozzle MoS2 N-MQL method reduced the surface roughness, cutting force, feed force, flank wear, total consumed energy, total carbon emission, and overall machining cost by 74.2 %, 63.9 %, 68.4 %, 66 %, 27.9 %, 0.4 %, and 6.39 %, respectively.

Parametric Analysis of EN 353 Alloy Using MQL Machining with Response Surface Method

Heat generated in any conventional machining between tool and work- piece can be minimized by the use of cutting fluids since the latter plays a vital role in terms of improving surface quality and its characteristics because of its properties like continuous lubrication, cooling and chips flushing etc. As extensive use of cutting fluids increase the machining costs, the problem can be overcome by employing a sustainable manufacturing technique known as Minimum Quantity Lubrication (MQL) which reduces the flow of cutting fluid. On the other hand researches are focusing on Nano based fluids which are gaining more importance. As nano based cutting fluids are colloidal mixture of nano sized particles and a base fluid, which enhance the heat transfer characteristics suitable for machining applications. The present paper focuses on the application of Hybrid Nano based cutting fluids for machining of alloy steel under different MQL flow conditions. Using response surface methodology (RSM), an optimum solution is obtained for the selected input parameters to the output response-surface roughness. A regression relation is developed between the input and output responses with the help of Response surface methodology (RSM).

Hole quality improvement in CFRP/Ti6Al4V stacks using optimised flow rates for LCO2 and MQL sustainable cooling/lubrication

Carbon fibre reinforced polymer/titanium stacks (CFRP/Ti6Al4V) are employed in aeronautics due to their excellent weight-to-strength ratio and corrosion properties. However, these same material properties present challenges for hole making which cannot be solved using conventional water-based metalworking fluids (MWFs), as they cause degradation of the composite. Moreover, environmental and health concerns require exploration of alternative cooling/lubrication solutions. In this study, a controlled mixture of liquid carbon dioxide (LCO2) and minimum quantity lubrication (MQL) was supplied through the drilling tool. The effect of varying LCO2 and MQL flow rates was evaluated on cutting forces, temperatures, and several hole quality outputs. The optimal flow rates were then determined through multi-objective optimisation. The results show that the cooling/lubrication flow rate greatly affects the measured outputs, and that supplying LCO2 + MQL with optimised flow rates helps achieve superior quality holes in CFRP, Ti6Al4V and CFRP/Ti6Al4V stacks.

Evaluation of adequacy of lubricants in MQL micro-drilling by a developed analytical model and experiments

Minimum Quantity Lubrication (MQL) plays a very important role in providing effective lubrication in micromachining. The present study developed an analytical model to determine whether the given value of MQL flow rate was sufficient or deficient for different cutting conditions in a micro-drilling process. Similar study in micro-drilling is lacking in literature. The model was formulated considering the tool geometry, experimental value of chip thickness and workpiece material properties. The size effect phenomenon was also considered during the development of the model demonstrating the variation of rake angle in ploughing, transition and shearing regions of the micro-drilling process. It was observed that the required area of lubrication increased with feed from 1 to 8 μm/rev in the ploughing region and decreased in transition and shearing regimes. The size of the MQL droplets was experimentally determined to calculate the effective number of droplets impinging on the target area. Thereafter, the total effective wetting area was found out using the effective number of droplets and wetting area. Finally, the required area of lubrication and total effective wetting area were compared to determine the condition of sufficiency or deficiency. On transition from ploughing to shearing region, there was variation in the sufficiency and deficiency conditions of the given MQL flow rate at different cutting conditions of feed and spindle speed. The study clearly indicated that the condition of sufficiency of MQL flow rate could be consistently accomplished during micro-drilling under the higher cutting condition of feed and spindle speed.

Sustainable Vegetable Oil-Based Minimum Quantity Lubrication Assisted Machining of AZ91 Magnesium Alloy: A Grey Relational Analysis-Based Study

The implementation of magnesium alloys in a multitude of industries has been proven to be a mere effect of their attractive light weight, corrosion resistant, and biodegradable properties. These traits allow these materials to portray an excellent sustainable machinability. However, with increasing demand, it is essential to explore sustainable means of increasing production while mitigating reductions in sustainability. The current work aims to assess and optimize the high-speed machinability of AZ91 with the use of a vegetable oil-based minimum quantity lubrication (MQL) system using the grey relational analysis (GRA) on the basis of chip morphology and tool wear. The investigation entailed a full factorial design with MQL flow rate, cutting speed, and feed rate as the control parameters and flank wear, land width, chip contact length, saw-tooth pitch, chip segmentation ratio, chip compression ratio, and shear angle as the output responses. The optimal control parameters predicted and experimentally confirmed were an MQL flow rate of 40 mL/h, cutting speed of 300 m/min, and feed rate of 0.3 mm/rev. The usage of said optimal parameters results in a grey relational grade improvement of 0.2675 in comparison to the referenced first experimental run. Moreover, the MQL flow rate was regarded as the critical variable with a contribution percentage of 20% for the grey relational grade.

A comparative analysis of chip shape, residual stresses, and surface roughness in minimum-quantity-lubrication turning with various flow rates

In this research, an experimental investigation was carried out to investigate the interaction between various turning parameters and different minimum quantity lubrication (MQL) flow rates and compare their effects on chip shape and surface integrity characteristics in low speed turning and high speed turning of AA6061-T6. The turning parameters included cutting speed, feed rate, and depth of cut. The flow rates comprised 3.5 $$\mathrm{ml}/\mathrm{min}$$ , 10 $$\mathrm{ml}/\mathrm{min}$$ , and 15 $$\mathrm{ml}/\mathrm{min}$$ , and the surface integrity characteristics consisted of average arithmetic surface roughness, height peak from the valley, and axial and hoop surface residual stresses. The results showed that cutting conditions including cutting speed, feed rate, and depth of cut affected chip shape, while MQL flow rate had no impact on chip shape. The lowest values of cutting speed, feed rate, and depth of cut, equal to 145 $$\mathrm{m}/\mathrm{min}$$ , 0.07 $$\mathrm{mm}/\mathrm{rev}$$ , and 0.66 $$\mathrm{mm}$$ , respectively, resulted in the smallest residual stresses for all the flow rates. Moreover, the smallest surface roughness parameters were obtained at the lowest feed rate (0.07 $$\mathrm{mm}/\mathrm{rev}$$ ) for all the flow rates, whereas there were high interaction effects between cutting speed and flow rate and depth of cut and flow rate. Finally, turning with the minimum quantity lubrications of 3.5 $$\mathrm{ml}/\mathrm{min}$$ and 10 $$\mathrm{ml}/\mathrm{min}$$ , respectively, is suggested to obtain the best overall surface integrity characteristics. These lower values of flow rate are suitable to reduce machining costs, protect the environment, and preserve the machinist’s health. Since most of the previous research studies focused on the comparison of the turning environments including dry, MQL, wet, and cryogenic and only a few research works on the comparative analysis of MQL turning with different flow rates were carried out, the results of the present research can be utilized as a reference for future works in this field.

Multi-response optimization in turning of EN-24 steel under MQL

Cutting fluids used in manufacturing industry have environmental and economic drawbacks. In order to reduce the negative effects associated with cutting the fluids, it is now becoming indispensable to move towards more sustainable techniques. In this research work, the turning of EN-24 steel under minimum quantity lubrication (MQL) environment have been done. The study has been completed three phases. The first phase deals with planning of experiments based on Box-Behnken design. The influence of input process parameters i.e., cutting speed, feed rate, depth of cut and MQL flow rate have been investigated on output parameters i.e., surface roughness, tool wear, cutting temperature and cutting force. The desirability approach strategy has been used for multi-response optimizationof input parameters in the second phase.The third step deals with analysis of results using SEM, 3D surface graphs and main effect graphs. The confirmation experiments have been carried out to verify the developed model. Experimental results revealed that, the turning performance under high MQL flow rate has been found to be the most effective parameter on mean surface roughness, cutting temperature, tool wear and cutting force.

Model Assessment of an Open-Source Smoothed Particle Hydrodynamics (SPH) Simulation of a Vibration-Assisted Drilling Process

Minimum Quantity Lubrication (MQL) is a cooling and lubrication variant applied, for instance, in drilling processes. In the present approach, a new vibration-assisted drilling process is analyzed, which has considerable potential for manufacturing of extremely hard materials. Within this process, the MQL gas/liquid transport in the presence of a vibrating and rotating twist drill bit in the borehole is to be studied. Multiphase computational fluid dynamics is applied to analyze and optimize the MQL flow. However, applying conventional CFD methods with discretized continuum equations on a numerical grid is challenging in this process, as the vibrating drill bit frequently closes the gap in the borehole, where even dynamic grid application fails. The ability to use an open-source Smoothed Particle Hydrodynamics (SPH) meshless method to analyze the lubrication media flow is carried out to accurately and efficiently address this problem and overcome the severe limitations of conventional mesh-based methods. For a feasibility study of the method, the MQL air phase in the dynamic drill cavity is analyzed by SPH and validated against conventional CFD method results. The present study shows insufficient results of the SPH method, both in terms of solution plausibility and computational cost, for simulation of the problem at hand.

An experimental study on cutting temperature and burr in milling of ferritic stainless steel under MQL using nano graphene reinforced cutting fluid

In this experimental study, cutting temperatures and burr forms were investigated during MQL (Minimum Quantity Lubrication) milling of AISI 430 ferritic stainless steel. In the experiments, uncoated and TiN (Titanium Nitride) coated WC (Tungsten Carbide) cutting tools were used and the experiments were performed under dry and MQL conditions. A commercial vegetable cutting fluid was chosen as cutting fluid and MQL flow rates were applied at 20 ml/h and 40 ml/h. Additionally, a nanofluid was prepared by adding nano graphene particles to the vegetable cutting fluid at 0,5%wt. Depending on the experimental results, low cutting temperature and small burr forms could have been obtained in the results of using TiN coated WC cutting tool and applying MQL method. In addition, the minimum cutting temperature and burr form were observed during MQL milling with nanofluid. Copyright © 2017 VBRI Press.

The effects of liquid-CO2 cooling, MQL and cutting parameters on drilling performance

An investigation is made into the effects of liquid carbon dioxide (LCO2) cooling, minimum-quantity lubrication (MQL) and cutting speed in drilling. Experimental measurements of torque, thrust force and temperature are made over a wide range of process and operating conditions. The resulting empirical models are used to quantify the individual contributions of the controlled parameters on drilling performance, and to facilitate temperature-based process optimization. Of particular interest is the need to carefully adjust the LCO2 flow rate for any combination of MQL flow rate and cutting speed. The optimization is validated both in simulation and actual drilling tests.

Performance evaluation of minimum quantity lubrication technique in grinding of AISI 202 stainless steel using nano-MoS2 with vegetable-based cutting fluid

Due to environmental issue and stringent rules over defilement and contamination of the environment, the demand for renewable and biodegradable cutting fluids is increasing. In this study, an eco-friendly minimum quantity lubrication (MQL) technique using vegetable oil–based cutting fluid (rapeseed oil) by varying MQL flow rate and MQL pressure was investigated in the grinding of AISI 202 stainless steel. In addition to explore the cooling capabilities of rapeseed oil, nano-MoS2 was added to the rapeseed oil to prepare different concentrations (0.5 wt% and 1.0 wt%) of nanofluids. The main objective of this experiment is to examine the performance of different grinding environments (dry, flood, pure MQL, and nanofluid MQL) with respect to grinding characteristics, namely, grinding forces, surface morphology, surface roughness, and temperature. Experimental results revealed that NFMQL grinding with vegetable oil was performed much superior as compared with the dry, wet, and pure MQL machining. The lowest specific normal force and tangential force are observed to be 9.2 N/mm and 0.76 N/mm respectively under 1.0 wt% concentration of MoS2 nanoparticles at oil flow rate of 120 ml/h and air pressure 90 psi under MQL grinding condition, which decreased by 43% and 33%, respectively, as compared with dry conditions. Furthermore, the application of nanofluid also leads to the reduction of surface roughness and surface temperature. MQL application with MoS2 nanofluid helps in effective flushing of chip material from the grinding zone, thereby improving the lubrication and cooling capabilities during the grinding of the AISI 202 stainless steel. In summary, appropriately chosen minimum quantity lubrication parameters can enhance the lubrication and cooling properties of the oil film and improve the grinding characteristics.

Effect of MQL flow rate on machinability of AISI 4140 steel

Many studies were performed about the influence of minimum quantity lubrication (MQL) technique on cutting performance in the literature, but there is no paper examining the effect of different MQL flow rates and cutting parameters on machinability of AISI 4140 material as a whole. In this study, the effects of different MQL flow rates and cutting parameters on surface roughness, main cutting force and cutting tool flank wear (VB), with great importance among the machinability criteria, and forming as a result of the machining of AISI 4140, were revealed. At the end of the experiments, it was determined that rise of flow rate affected main cutting forces positively to a certain extent; yet, it exhibited no significant effect on surface roughness, but reduced VB. Also, it was observed that both main cutting force and surface roughness increased with the increase of feed, while generally decreased with the increase of cutting speed. It was seen that flank wear was positively affected by the increase in flow rate; and this decreased with the increase in flow rate. R2 values obtained as 99.8% and 99.9% for main cutting forces and surface roughness values modeled statistically with the help of quadratic equations, respectively.

Optimisation of Parameters in Turning Using Herbal Based Nano Cutting Fluid with MQL

Abstract This paper focuses on finding the optimum value of cutting force Fz while turning of AISI 1045 steel using Al2O3 nano particles synthesised via herbal process with minimum quantity lubrication (MQL) technique. The process parameters considered are MQL flow rate, volume concentration of nano particles, speed, feed rate and depth of cut (DOC). Central composite face (CCF) centred design provides in depth analysis of main and interaction effects of process parameters and the response. Regression equation is developed for cutting force Fz which is further used in optimisation using genetic algorithm (GA). Optimum value of cutting force is 35.7Kgf corresponding to 5ml/min MQL flow rate, 0.6% volume concentration, 120m/min speed, 0.096mm/rev feed rate, 0.25mm DOC

Effectiveness of Near Dry Machining on Tool Performance in Bull Nose Milling of Aluminum Alloy 7075 T6

The paper investigated the effectiveness of near-dry machining also known as minimum quantity lubrication (MQL) on tool wear when aluminum alloy 7075-T6 was milled using bull nose carbide insert. The foregoing study found that the high tool wear was occurred in machining aluminum alloy 7075-T6 with uncoated carbide under dry machining. Due to that, dry machining was performed to examine its result with MQL. Different values of cutting parameter selected were cutting speed of 500 and 600 m/min, the feed rate of 0.12 and 0.15 mm/tooth, and axial depth of cut of 1.40 and 1.70 mm. 100 mL/h was set as MQL flow rate. Eight samples were performed on five axes milling machine according to a full factorial design. The tool wear was examined and measured progressively at every time interval using an optical microscope. From the analysis, MQL 100 mL/h at 500 m/min, 0.12 mm/tooth, and 1.40 mm was found to be better than dry machining. The adhesion wear mechanism was observed at both machining conditions. Near-dry machining with appropriate flow rate and machining parameters has the potential to contribute to long-term environmental friendly machining in line with the industrial revolution phase.

Effect of Minimum Quantity Lubrication and Dry Cutting on the Tool Life and Chip Morphology after Milling of Aluminum Alloy 7075-T6

This research deals the experimental works on the effect of minimum quantity lubrication (MQL) and dry cutting towards the cutting tool life and chip morphology in high-speed milling of aluminum alloy 7075-T6 with uncoated carbide tools. MQL and dry cutting were eco-friendly approaches that highlight essential issues in the field of manufacturing technology. Thus, further investigation required to observe the intensity of those approaches. The experiment was done on computer numerical control (CNC) five axes milling machine at distinct machining parameters, which are cutting speed (500 and 600 m/min), feed rate (0.12 and 0.15 mm/tooth) and axial depth of cut (1.4 and 1.7 mm), while the radial depth of cut restricted to 7 mm. The effect of fluid approaches and machining parameters on eight samples have analyzed the result of the setting of three factors and two levels in accordance with the full factorial design and analyzed further using ANOVA. The MQL flow rate was set at 100 mL/h. The tool life criterion was determined when the tool wear failure reached 0.30 mm. The chips collected from all machining conditions were taken to be examined using an optical microscope. The empirical model of tool life for the MQL and dry cutting has been developed within the experimental ranges evaluated. The prolonged tool lifespan beyond 20.14 minutes and favorable chip formation were obtained at 500 and 600 m/min, 0.12 mm/tooth, and 1.40 mm, respectively under MQL 100 mL/h. MQL 100 mL/h appeared to be one fit for metal cutting industry that prioritizes clean and green machining as well as the use of appropriate machining parameters as it leads to economic benefits in terms of fluid cost-saving and the better machinability.

Experimental investigation and modelling of MQL assisted turning process during machining of 15-5 PH stainless steel using response surface methodology

Built-up-edge formation is one of the problems in conventional (flood) machining of 15-5 precipitated hardened stainless steel (PH SS) which results in poor product quality. Further, concentration on stringent environmental conscious regulations has been increasing in metal cutting industries due to environmental pollution. The present work target is to address these problems using minimum quantity lubrication (MQL) machining technique. MQL machining technique is one of the promising techniques for the metal cutting industries because it satisfies the stringent environmental conscious regulations set for metal cutting industries in terms of usage and disposal of chemically contaminated emulsion based coolants. In the present work, studied the effect of MQL cooling, process parameters on turning performance characteristics and also established a relationship between the turning controllable process parameters and responses in the machining of 15-5 PH SS using response surface methodology (RSM) under MQL environment with tungsten carbide cutting insert. Spindle speed (v), feed rate (f), depth of cut (d) and MQL flow rate (Q) have been taken as MQL machining process parameters. Output turning performances considered were surface roughness (Ra), tool flank wear (Tw) and material removal rate respectively. Experiments were done based on the central composite design of RSM. From RSM analysis, it was noticed that developed mathematical models predicted the performance results close to the experimental results. Further, it was observed that surface roughness and tool wear reduced significantly with an increase in MQL flow rate respectively.

Multi-Objective Optimization for Grinding of AISI D2 Steel with Al₂O₃ Wheel under MQL.

In the present study, the machinability indices of surface grinding of AISI D2 steel under dry, flood cooling, and minimum quantity lubrication (MQL) conditions are compared. The comparison was confined within three responses, namely, the surface quality, surface temperature, and normal force. For deeper insight, the surface topography of MQL-assisted ground surface was analyzed too. Furthermore, the statistical analysis of variance (ANOVA) was employed to extract the major influencing factors on the above-mentioned responses. Apart from this, the multi-objective optimization by Grey–Taguchi method was performed to suggest the best parameter settings for system-wide optimal performance. The central composite experimental design plan was adopted to orient the inputs wherein the inclusion of MQL flow rate as an input adds addition novelty to this study. The mathematical models were formulated using Response Surface Methodology (RSM). It was found that the developed models are statistically significant, with optimum conditions of depth of cut of 15 µm, table speed of 3 m/min, cutting speed 25 m/min, and MQL flow rate 250 mL/h. It was also found that MQL outperformed the dry as well as wet condition in surface grinding due to its effective penetration ability and improved heat dissipation property.

Effects of nano graphene particles on surface roughness and cutting temperature during MQL milling of AISI 430 stainless steel

Abstract Stainless steel is hard-to-cut due to its material specifications and many problems are encountered machining it. Nevertheless, stainless steel is frequently preferred in industry and its use increases. In this experimental study, the machining of AISI 430 ferritic stainless steel under dry, MQL (minimum quantity lubrication) and nanofluid MQL milling conditions was investigated. Nanofluids were prepared by adding 1 wt.-% and 2 wt.-% nano graphene to commercial vegetable cutting fluid. In these experiments, uncoated WC (tungsten carbide) and TiN (titanium nitride) coated WC cutting tools were used and MQL flow rates were selected as 20 ml × h−1 and 40 ml × h−1. Surface roughness and cutting temperatures were measured and the effects of using nanofluid, MQL flow rate, and TiN coated cutting tools were specified. According to the experimental results, the MQL method was shown to be beneficial for reducing cutting temperature and surface roughness values and the nanofluid MQL yielded minimum values. Moreover, TiN coating and an increased MQL flow rate decreased cutting temperature and surface roughness.