Pure Minimum Quantity Lubrication Research Articles

Optimizing SKD-61 steel machining for marine component manufacture: A grey-Taguchi study on nanofluid minimum quantity lubrication

SKD-61 steel finds extensive application in various sectors, including the marine industry where materials must withstand harsh aquatic conditions. In this study, we employ the Grey-Taguchi approach to optimize surface roughness (Ra), cutting force (Fc), and material removal rate (MRR) when hard-milling SKD-61 steel in pure minimum quantity lubrication (MQL) and nanofluid MQL environments, aligning with the demands of marine engineering. The orthogonal array method generates a set of experiments based on four input parameters: cutting speed, depth of cut, feed per tooth, and cutting condition, which are essential factors in marine component manufacturing. Our approach combines Grey relational analysis (GRA) with the Taguchi method to enhance multi-objective outcomes in machining. The results of this marine-focused study reveal that the lowest surface roughness, cutting force, and highest material removal rates are attained when the cutting conditions align with the principles of nanofluid MQL at a cutting velocity of 80 m/min, a depth of cut of 0.2 mm, and a feed per tooth of 0.01 mm/tooth. Keywords: hard milling, nanofluid MQL, optimization machining parameters; Grey relational analysis; Taguchi

Grindability Evaluation of Ultrasonic Assisted Grinding of Silicon Nitride Ceramic Using Minimum Quantity Lubrication Based SiO2 Nanofluid

Minimum quantity Lubrication (MQL) is a sustainable lubrication system that is famous in many machining systems. It involve the spray of an infinitesimal amount of mist-like lubricants during machining processes. The MQL system is affirmed to exhibit an excellent machining performance, and it is highly economical. The nanofluids are understood to exhibit excellent lubricity and heat evacuation capability, compared to pure oil-based MQL system. Studies have shown that the surface quality and amount of energy expended in the grinding operations can be reduced considerably due to the positive effect of these nanofluids. This work presents an experimental study on the tribological performance of SiO2 nanofluid during grinding of Si3N4 ceramic. The effect different grinding modes and lubrication systems during the grinding operation was also analyzed. Different concentrations of the SiO2 nanofluid was manufactured using canola, corn and sunflower oils. The quantitative evaluation of the grinding process was done based on the amount of grinding forces, specific grinding energy, frictional coefficient, and surface integrity. It was found that the canola oil exhibits optimal lubrication performance compared to corn oil, sunflower oil, and traditional lubrication systems. Additionally, the introduction of ultrasonic vibrations with the SiO2 nanofluid in MQL system was found to reduce the specific grinding energy, normal grinding forces, tangential grinding forces, and surface roughness by 65%, 57%, 65%, and 18% respectively. Finally, regression analysis was used to obtain an optimum parameter combinations. The observations from this work will aid the smooth transition towards ecofriendly and sustainable machining of engineering ceramics.

Performance evaluation of AlTiN coated carbide tools during machining of ceramic reinforced Cu-based hybrid composites under cryogenic, pure-minimum quantity lubrication and dry regimes

In this study, the machining performance of 10 wt.% B-Ti-SiCp particles reinforced Cu-based hybrid composites were investigated under dry, minimum quantity lubrication (MQL) and cryogenic LN2 assisted environments during milling. In-depth analyses comprising of tool wear development, surface roughness, surface texture, cutting temperature, cutting energy, and chip morphologies were thoroughly performed. According to the experimental results, MQL environment was found to be most influential method to prevent build-up-edge formation. In addition, LN2 assisted cryogenic coolant medium is the most powerful method in all machining characteristics as providing better tribological properties. The paper proposes a novel approach for improved machinability performance of Cu-based hybrid composites with sustainable techniques.

Influence of graphene nanofluid on various environmental factors during turning of M42 steel

Abstract Cutting fluids significantly improve machining efficiency due to their high contribution to cooling and lubrication. However, the negative effects of traditional cutting fluids and worker health are valid reasons to seek alternatives. One of the alternatives is the minimum quantity lubrication (MQL) system. The MQL system, in which a small quantity of cutting oil is sent to the cutting point with pressure, gives very good results in light and medium cutting conditions. However, the MQL system may be insufficient for turning materials that are difficult to machine, such as M42 steel, which has excellent hardness under high temperature. In such cases, nano additives are added to the coolant to enhance the thermal conductivity and tribological properties of the base coolant. In this study, the effectiveness of graphene nanofluids was investigated comparing with dry and pure MQL to determine the efficiency of graphene nanofluid. In addition, cutting speeds and feed rates of three different levels were used in the experimental design to examine the behavior of the cooling methods under different cutting speeds. After experiments, a hybrid multicriteria decision making approach known as Multi-Objective Optimization by Ratio Analysis (MOORA) integrated with Analytic Hierarchy Process (AHP) was used to identify suitable turning parameters. Surface roughness, cutting temperature and tool wear were the output characteristics examined. Further, the morphology of chips was investigated by scanning electron microscope. The experimental results and proposed hybrid AHP-MOORA indicates that graphene nanofluids considerably decrease the surface roughness by 91%, tool wear by 95% and cutting temperature by 82% with dry environment and surface roughness by 66%, tool wear by 86% and cutting temperature by 57% with oil environment in turning M42 steel.

Analysis, modeling, and multi-objective optimization of machining Inconel 718 with nano-additives based minimum quantity coolant

In the current study, analysis, modeling, and optimization of machining with nano-additives based minimum quantity lubrication (MQL) during turning Inconel 718 are presented and discussed. Multi-walled carbon nanotubes (MWCNTs) and aluminum oxide (Al2O3) gamma nanoparticles were utilized as used nano-additives. The studied design variables include cutting speed, feed rate, and nano-additives percentage (wt. %). Three machining outputs were considered namely: flank wear, surface roughness, and energy consumption. The novelty here focuses on improving the MQL heat capacity by employing two different nano-fluids. The analysis of variance (ANOVA) technique was employed to investigate the influence of the design variables on the studied machining outputs. The results demonstrated that the usage of MQL-nanofluids improved the cutting process performance compared to the classical approach of MQL. It was found that 4 wt. % of added MWCNTs decreased the flank wear by 45.6% compared to the pure MQL. Similarly, it was found that 4 wt. % of added Al2O3 nanoparticles improved the tool wear by 37.2%. Besides, the nanotubes additives showed more improvements than Al2O3 nanoparticles in terms of tool wear, surface quality, and energy consumption. Regarding the modeling stage, artificial neural network (ANN), adaptive neuro-fuzzy inference system (ANFIS), and genetic programming (GP) are employed to model the measured outputs in terms of the studied parameters. These soft computing approaches provide various advantages through their self-learning capabilities, fuzzy principles, and evolutionary computational concept. In addition, a comparison among the developed models has been conducted to select the most accurate approach to present the machining characteristics. Finally, the non-dominated sorting genetic algorithm (NSGA-II) was utilized to optimize the studied cutting processes. Moreover, a comparison between the optimized results from different approaches is presented. The proposed methodology presented in this work can be further implemented in other machining cases to model, analyze as well as optimize the machining performance, especially for the hard-to-cut materials which are commonly used in different industries.

Performance evaluation of the minimum quantity lubrication with Al2O3- mixed vegetable-oil-based cutting fluid in drilling of AISI 321 stainless steel

Abstract Due to increased awareness of ecological and health related problems, the researchers are actively searching for renewable and biodegradable cutting lubricants. Vegetable oils with solid lubricants are being explored as a potential source of environmentally helpful lubricants due to good combination of biodegradability, renewability and fabulous lubrication performance. Although sunflower oil poses good cooling capability, yet its application has not been explored extensively in drilling. Therefore, in this research work minimum quantity lubrication (MQL) technique with Al2O3-mixed vegetable-oil-based cutting fluid was implemented. The main objective of this experiment is to analyze the performance of various coolant-lubricant environments (dry, flood, pure MQL and nanofluid MQL) with regard to drilling forces, surface roughness, drill tip temperature and tool wear mechanism in the drilling of AISI 321 stainless steel by using HSS drill tools. In the MQL conditions, coolant supply rate and air pressure are fixed at 120 mL/hr and 6 bar respectively. In addition to explore the cooling capabilities of sunflower oil, nano-Al2O3 were added to the sunflower oil to prepare different concentration (0.5 wt.%, 1.0 wt.% and 1.5 wt.%) nanofluids. Results indicated that MQL drilling with Al2O3-mixed vegetable-oil-based cutting fluid achieved much better performance as compared to the dry, wet and pure MQL drilling. Thrust force, torque, surface roughness and drill tip temperature approximately reduced 44 %, 67 %, 56 % and 26 % respectively at the 30th hole under nanofluid MQL drilling (with 1.5 wt.% of aluminium oxide nanoparticles) as compared to flood conditions. Moreover, tool wear rate reduced significantly while machining under NFMQL conditions. Better results of nanofluid MQL drilling may be attributed to the fact that NFMQL is capable for producing higher cooling effect due to the lubrication characteristics of nanoparticles.

Tribological behaviour of nanofluids under minimum quantity lubrication in turning of AISI 1055 steel

The objective of the present study is to investigate the tribology characteristics of aluminium (Al 2 O 3 ) nanoparticles as an additive in vegetable oil during machining with minimum quantity of lubrication. The effect of minimum quantity nanofluid lubrication (MQ nf L) on the cutting forces, surface roughness, and cutting tool wear during the turning process of medium carbon steel (AISI 1055) has been evaluated and compared with the pure minimum quantity lubrication (MQL), flood and dry turning. For the MQ nf L, the nano-alumina (Al 2 O 3 ) particles of 20 ɳm size are used with soybean oil in 1% and 3% w/v concentration. The experiments are conducted at two cutting speeds of 38 mm/m and 60 mm/m with varying two feed values of 0.06 mm/rev and 0.11 mm/rev under above mentioned lubricating conditions. The results showed that MQ nf L and pure MQL are much more efficient as compared to other lubrication conditions, in terms of improving surface quality, lower cutting forces and reducing tool wear. Further, as the concern with MQ nf L, the 1% concentration of nano-particles is more effectual than 3% to reduce overall cutting forces where as 3% MQ nf L revealed outstanding cutting performance in terms of tool wear.

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.

Experimental investigation on the performance of MQL drilling of AISI 321 stainless steel using nano-graphene enhanced vegetable-oil-based cutting fluid

The present work aims to examine the drilling performance of AISI 321 stainless steel using vegetable-oil-based cutting fluid under different minimum quantity lubrication (MQL) strategies (with and without graphene nanoparticles). Experimental results indicated that MQL drilling with 1.5 wt% of graphene nanoparticles considerably reduced the thrust force (27.4%), torque (64.9%), surface roughness (33.8%) and coefficient of friction (51.7%) at the 30th hole as compared to pure MQL condition and also improved the tool life. In brief, the sufficient quantity of graphene nanoparticles in nanofluid MQL drilling can boost the lubrication performance and increase the stability of lubrication film, which improves the drilling characteristics.

Toward sustainable micro-drilling of Inconel 718 superalloy using MQL-Nanofluid

The application of micro-mechanical cutting operations, such as micro-drilling, is crucial for producing microsystem components. In the production of jet engine parts, Inconel 718 superalloy has been used to produce these components due to its high performance at high temperatures. Due to the low thermal conductivity and the high work hardening tendencies of Inconel 718, a high amount of the cutting temperature dissipates toward the cutting tool instead of the chip. When using micro-scale drilling (micro-drilling), heat dissipation becomes more challenging. This affects the tool life and the machined surface quality; therefore, when machining these alloys, a cutting fluid is required to decrease the high amounts of generated heat. Flood coolant is commonly used to reduce the cutting temperature; however, government regulations have been published for alternative cooling processes to decrease the influences of flood coolant on the environment and the operator’s health. Minimum quantity lubrication (MQL) has been used as an alternative to conventional cutting fluids because it minimizes the consumption of cooling lubricants and reduces the environmental and health impacts; however, pure MQL cooling has an ineffective cooling ability. In order to enhance thermal conductivity, viscosity, and wettability of the MQL base fluid, an MQL-nanofluid was used. This study investigated the performance of a micro-drilling process using an MQL-nanofluid with regard to thrust forces, tool wear, and burr formation, and compared it to flood cooling and a pure MQL. Micro-drilling experiments involving Inconel 718 were conducted using the same cutting parameters, drilling tool, and machining environment for both the MQL and the flood coolant. The results revealed that the MQL-nanofluid approach was promising in terms of machining outputs as well as sustainability.

Grinding performance of bearing steel using MQL under different dilutions and wheel cleaning for green manufacture

Cutting fluids have a fundamental role in machining, especially in grinding, since they are responsible for lubrication and refrigeration of the cutting region. On the other hand, they may cause damage to the environment and to the health of the operators. Thermal damage, geometric inaccuracies and degradation of the surface integrity of the workpiece are diminished with the use of cutting fluids. While in the conventional application of cutting fluid a large amount of oil or emulsion of oil with water is used, in the minimum quantity lubrication (MQL) technique a small amount of oil is applied via a jet of compressed air reaching, in many cases, results comparable to the conventional method. However, the lower cooling capacity of MQL and the clogging of the wheel pores caused by the hot chips are obstacles to be overcome. This work evaluates the addition of water to the MQL method in the external cylindrical plunge grinding of AISI 52100 steel to improve the deficiencies of this technique. The results analyzed include surface roughness (Ra), workpiece surface damages, roundness deviation, grinding wheel wear, grinding power, acoustic emission, workpiece subsurface microhardness and microstructure for conventional method, MQL with pure oil (1:0) and MQL with water in 1:1, 1:3 and 1:5 oil-water proportions with and without grinding wheel cleaning (a jet of compressed air towards the wheel surface to remove the chips which clog the wheel pores). MQL with pure oil produced the worst results in this work, but dilution of oil in water benefited this lubricant-refrigerant technique. In addition, the diluted MQL 1:5 associated with wheel cleaning jet (WCJ) was the alternative method that most closely approximated the results of the conventional technique, indicating the potential for using MQL with WCJ widely in the industry. However, it is necessary to continue researching this technique in order it could even outperform the conventional method in all its output variables.

Performance Evaluation of Inconel 718 under vegetable oils based nanofluids using Minimum Quantity Lubrication Grinding

The growing demands for high productivity in machining requires large amount of cutting fluids to control the lubrication phenomenon efficiently. The application of lubricants/coolants in machining operation has improved the efficiency of these operations, however the disposal of such coolants is hazardous to the eco-system. Hence eco friendly cutting fluids are required urgently to solve the environment problems related with traditional fluids. Minimum Quantity Lubrication (MQL) is an environmentally friendly method and efficient technique of applying cutting fluids in machining processes. In the present study Grinding of Inconel-718 has been investigated with regard to forces, surface roughness, grinding energy and G-Ratio under different cooling lubrication strategies i,e, flood, pure MQL and nanofluid MQL. For pure MQL technique sunflower and ricebran were used as base fluids, and different types of nanofluids were prepared by adding 1%, 0.5% Al2O3 nano-particles to these vegetable oils for evaluating the grinding process. From the results it is observed that sunflower has given better surface integrity and low grinding energy using pure MQL technique. Moreover, addition of Al2O3 nano-particles in the base fluid further enhanced the quality of surface, lower the grinding energy and enhanced the G-Ratio. Better surface integrity achieved under nanofluid MQL technique might be attributed to the filling and polishing effects of nano-particles along with good anti friction behaviour. Moreover nano-particles form a shearing film by penetrating into pores of workpiece surface resulted in shearing action leads to high values of G-Ratio. Hence results indicated that vegetable based nanofluids has the potential to be successfully apply at the grinding of hard materials. It appears that the proposed cooling strategy may conceivably improve the efficiency of cutting activities as far as machining quality, costs, and ecological insurance. This can enable in reduction of expensive fluid wastages which can lead to environmental friendly machining.

Experimental evaluation of an eco-friendly grinding process combining minimum quantity lubrication and graphene-enhanced plant-oil-based cutting fluid

Abstract Minimum Quantity Lubrication (MQL) is increasingly applied in the grinding process of the hard-to-cut material (HCM) as an eco-friendly and efficient technology of lubricating and cooling. The grinding characteristics of the HCM directly affect their reliability and serviceability and so, evaluating the grinding characteristics during the MQL is very vital. In this work, the MQL with different weight concentrations of graphene-enhanced plant-oil-based cutting fluids (POBCFs) (0.05 wt%, 0.1 wt%, 0.15 wt%, and 0.2 wt%) was adopted in the grinding of the TC4 alloy, where the graphene nanoparticle (GPNP) was added to the POBCF for preparing the graphene-enhanced POBCF for improving the grinding characteristics of the TC4 alloy. The experimental evaluation of the grinding characteristics of the TC4 alloy was carried out through the grinding experiments during the six working conditions (dry, pure MQL (PMQL), and four graphene MQL (GMQL)), and the optimal working condition was the GMQL (0.1 wt%). The influence mechanisms of the GPNP on the grinding characteristics with respect to the grinding force, grinding temperature, specific grinding energy, and surface integrity were revealed. In summary, the oil films generated during the grinding area exhibit excellent cooling and lubricating performances and the appropriate amount of GPNPs can strengthen the oil film performances in both cooling and lubricating to improve the grinding characteristics. The research results show that the GPNP exhibits a remarkable impact in improving the grinding characteristics and provide the experiment basis for applying the GPNP to the MQL grinding.

Nanofluid-based Minimum Quantity Lubrication (MQL) Face Milling of Inconel 625

Machining with minimum quantity lubrication (MQL) has gained widespread attention to boost machining performance of difficult to machine materials such as Ni-Cr alloys, especially to reduce the negative impact of conventional flooded machining on environment and machine operator health. The present study is aimed to evaluate MQL face milling performance of Inconel 625 using nano cutting fluid based on vegetable oil mixed with multi-walled carbon nanotubes (MWCNT). Experiments were designed with 2-level factorial design methodology. ANOVA test and desirability optimisation method were employed to arrive at optimised milling parameters to achieve minimum tool wear and machined surface quality. Experiments were performed under nanoparticles based minimum quantity lubrication (NMQL) conditions using different weight concentrations of MWCNT in base oil: 0.50, 0.75, 1, 1.25 and 1.5 wt. %; and pure MQL environment (without nanoparticles). The optimal MQL milling parameters found are cutting speed: 47 m/min, table feed rate: 0.05 mm/tooth and depth of cut: 0.20 mm. The results revealed improvement in the surface finish (Ra) by 17.33% and reduction in tool flank wear (VB) by 11.48 % under NMQL face milling of Inconel 625 with 1% weight concentration of MWCNT in base oil compared to pure MQL machining conditions.

Research on surface integrity in graphene nanofluid MQL milling of TC21 alloy

As a new type of damage-tolerance titanium alloy, TC21 alloy is widely used in aerospace. However, TC21 is a difficult-to-machine material owing to its low thermal conductivity, high chemical activity and low elasticity modulus. In this work, minimum quantity lubrication (MQL) with graphene nanofluid was adopted in TC21 milling. In order to evaluate the effects of graphene nanoparticle on the surface integrity, a series of milling experiments were performed under the dry, gas, pure MQL and graphene nanofluid MQL condition respectively. Results showed that the graphene additive was effective for improving the surface integrity. Overall, the results could be explained that graphene additive could enhance the cooling and lubrication performances of the oil film formed in cutting zone. The findings of this work are expected to give a feasibility and some experimental basis for the application of the graphene additive in MQL milling.

Research on surface integrity in graphene nanofluid MQL milling of TC21 alloy

As a new type of damage-tolerance titanium alloy, TC21 alloy is widely used in aerospace. However, TC21 is a difficult-to-machine material owing to its low thermal conductivity, high chemical activity and low elasticity modulus. In this work, minimum quantity lubrication (MQL) with graphene nanofluid was adopted in TC21 milling. In order to evaluate the effects of graphene nanoparticle on the surface integrity, a series of milling experiments were performed under the dry, gas, pure MQL and graphene nanofluid MQL condition respectively. Results showed that the graphene additive was effective for improving the surface integrity. Overall, the results could be explained that graphene additive could enhance the cooling and lubrication performances of the oil film formed in cutting zone. The findings of this work are expected to give a feasibility and some experimental basis for the application of the graphene additive in MQL milling.

MQL milling of TC4 alloy by dispersing graphene into vegetable oil-based cutting fluid

Titanium alloy TC4 is widely used in aerospace, petrochemical, shipbuilding, automobile, and medicine due to its excellent comprehensive performances. However, TC4 is a difficult-to-machine material because of its low thermal conductivity, large friction coefficient, high chemical activity, and low elasticity modulus. In this paper, Minimum Quantity Lubrication (MQL) with vegetable oil-based cutting fluid was adopted in TC4 milling. Meanwhile, graphene nanoparticles were dispersed into the vegetable oil-based cutting fluid to improve the cooling and lubrication performances. In order to evaluate the performances, a series of milling experiments were conducted under the four cooling/lubrication conditions (dry, gas, pure MQL, and graphene MQL). The milling characteristics of TC4 in terms of milling force, milling temperature, tool wear, and surface integrity were compared. Results showed that the graphene additive was effective for improving the milling characteristics. Overall, the results could be explained that the graphene additive could enhance the cooling and lubrication performances of the oil film formed in the milling zone. The findings of this paper are expected to be meaningful to provide some experimental basis for the application of the graphene additive in MQL milling.

Experimental Investigation on the Compatibility of Nanoparticles with Vegetable Oils for Nanofluid Minimum Quantity Lubrication Machining

Several health and environmental related issues caused by the application of traditional cutting fluids in machining can be solved by implementing eco-friendly technologies such as minimum quantity lubrication (MQL). Moreover, nanofluid MQL has been proposed to enhance the cooling/lubricating properties of pure MQL and displays significantly good results for machinability. However, the mechanism on compatibility of nanoparticles with cutting fluids has not been explored. In this study, nanoparticles with different hardness and vegetable oils with different viscosity were selected for nanofluids preparation. The end milling experiments were carried out on 7050 material by applying MQL with particularly prepared nanofluids. The cutting force and surface roughness were measured corresponding to the machining performance. The compatibility of hardness of nanoparticles with viscosity of base fluids has been evaluated, and the mechanism has been analyzed by new-designed tribology tests. Results show that canola oil-based diamond nanofluids MQL exhibit the lowest cutting force and natural77 oil-based diamond nanofluids perform the lowest surface roughness with reduction of 10.71 and 14.92%, respectively, compared to dry machining condition. The research is novel and contributes to the machining of such materials at the industry level.

Surface Roughness in Nanofluid Minimum Quantity Lubrication Milling of AISI 430 Ferritic Stainless Steel

Abstract Stainless steels have been used in different fields such as automotive, aerospace, construction, medical instruments, etc. and machining operations have been applied in many of these sectors. However, machinability of stainless steel is difficult due to their hardening tendency and low thermal conductivity. In addition, researchers have struggled with improving the surface quality of machined stainless steel parts. For this reason, a surface roughness investigation was carried out in MQL (minimum quantity lubrication) milling of AISI 430 ferritic stainless steel. The experiments were conducted using uncoated and TiN (titanium nitride) coated WC (tungsten carbide) cutting tools under dry, pure MQL and nanofluid MQL conditions. A commercial vegetable cutting fluid was used as a base fluid and two nanofluids were prepared by adding 0.5 and 1 weight percent nanographene particles to the vegetable cutting fluid. In MQL milling operations, MQL flow rates were adjusted at 20 and 40 mL/h and spindle speed, feed rate, and depth of cut were selected as 995 rpm, 180 mm/min, and 0.5 mm, respectively. Depending on the experimental results, lower surface roughness values were obtained in nanofluid MQL milling due to the cooling and lubrication effects of nanographene particles.

A Review of Minimum Quantity Lubrication Technique with Nanofluids Application in Metal Cutting Operations

Minimum quantity lubrication (MQL) technique did not only serve as a better alternative to flood cooling during machining but enhance better surface finish, minimizes the cost, reduces the impact loads on the environment and health hazards on the operation personnel. However, the coolant or lubrication media used in MQL technique posed certain restrictions especially at very high cutting speeds where the lubricating oil tends to evaporates as it strikes the already heated cutting tool at elevated temperature. Desire to compensate for the shortcomings of the lubricating media in the MQL technique led to the introduction of nanoparticles in the cutting fluids for use in the MQL lubrication process. Nanoparticles have much higher and stronger temperature-dependent thermal conductivity and enhanced heat transfer coefficient at very low particle concentration, which are key parameters for their enhanced performance in many of the machining applications. Optimizing the nanoparticles concentration leads to efficiency in most of their application. Their ball bearing effect lubrication at the cutting zone through formation of film layer which reduces friction between the contact surfaces thereby reducing cutting force, temperature and tool wear. It has been reported in various studies that nanoparticles introduction in cutting fluids led to excellent machining performance in reduction of cutting forces, reduced tool wear, reduced cutting temperature and improved surface finish of the work piece thereby increasing productivity and reduction of hazards to the health of personnel and the environment better than the pure or conventional MQL process. Thus, the application of various nanoparticles and its performances in metal cutting operations with respect to the cutting forces, surface finish, tool wear and temperature at the cutting zone are evaluated and highlighted.