Minimum Quantity Lubrication System Research Articles

Examination of the Effects of Abrasive Powder Amount Added to Minimum Quantity Lubrication System on Cutting Process

In machining operations, the cutting process is negatively affected due to the high temperature occurring between the cutting tool and the workpiece. The heat generated in the environment should be...

Experimental study of oil mist characteristics generated from minimum quantity lubrication and flood cooling

Abstract The use of metalworking fluids during machining can generate oil mist and endanger the health of workers. In order to study the characteristics and emission laws of oil mist generated by machining, this study constructed a test bench to simulate the turning process. Parameters affecting the oil mist generated in the minimum quantity lubrication (MQL) mode and flood cooling mode were studied by means of single-factor experiments, and the formation mechanisms of oil mist were analyzed. The results show that the oil mist generated by the MQL system has two main sources, the initial escape of oil mist into the air and the evaporation/condensation of oil mist. The centrifugation has almost no effect on oil mist formation in the MQL mode. The mass concentration of oil mist generated by the MQL system is proportional to the cutting oil flow rate. When the work-piece is at room temperature, increasing the air supply pressure and nozzle distance, increases the oil mist mass concentration. For the flood cooling mode, the concentration of centrifugal aerosol is linearly and positively correlated with the relative centrifugal force generated by the work-piece, and the coefficient of determination (R2) is above 0.97. The oil mist mass concentrations in MQL mode is 8.33 mg/m3~ 305.88 mg/m3. The MMD and SMD are 0.74 µm to 4.42 µm and 0.31 µm to 2.14 µm, respectively. The oil mist mass concentrations in flood cooling mode is 0.2 mg/m3~ 22.42 mg/m3. The MMD and SMD are 1.81 µm to 6.58 µm and 0.45 µm to 5.13 µm, respectively.

Machinability investigations of hardened steel with biodegradable oil-based MQL spray system

Excessive use of coolant is undesirable in machining due to environmental consciousness; thereby, small but efficacious (improved thermal and tribological properties) amount of coolant has been implemented using minimum quantity lubrication (MQL). In this study, attention was focused on the experimental investigations on tool flank wear, chip morphology, surface roughness (Ra and Rq) and chip-tool interface temperature in the machining of hardened steel (~ 40 HRC) under olive oil-assisted MQL spray system. As investigating factors, the cutting speed, feed rate, and depth of cut were oriented by following the Taguchi orthogonal array. Then, the cooling and lubrication mechanism of the olive oil-assisted MQL system has been discussed. Outcomes of this study showed that MQL is capable of generating favorable machining outcomes, i.e., lower tool flank wear, reduced temperature, and surface roughness in comparison with dry cutting. The reductions in Ra, Rq, and cutting temperature were about 23.4%, 23.8%, and 24% respectively in terms of mean values. The two types of dominant chip shapes, i.e., (1) continuous tubular and (2) discontinuous small diameter chips, were produced under the dry and MQL-assisted cooling method. In the nutshell, it is appropriate to claim that the overall thermal and tribological properties of olive oil-assisted MQL system are responsible for fruitful results during turning of hardened steel.

Submerged micro grinding: a metalworking fluid application study

Micro machining with micro pencil grinding tools (MPGTs) is an emerging technology that can be used to manufacture closed microchannel structures in hard and brittle materials as well as hardened steels like 16MnCr5. At their current operating conditions, these tools have a comparatively short tool life. In previous works, MPGTs in combination with a minimum quantity lubrication (MQL) system were used to manufacture microchannels in 16MnCr5 hardened steel. The study has shown that steel adhesions clog the abrasive layer of MPGTs, most likely resulting from insufficient lubrication. In this paper, a metalworking fluid (MWF) supply method was developed to improve the process: a submerged micro grinding process, in which machining takes place inside a pool of MWF. In this study, the effect of seven types of MWFs on material adhesions at the bottom surface of the tool is evaluated. Equivalent good MWFs are then compared in a micro pendulum grinding experiment till failure.

Wear behavior of textured tools under graphene-assisted minimum quantity lubrication system in machining Ti-6Al-4V alloy

Wear behavior of textured tools while turning Ti–6Al–4V under dry, minimum quantity lubrication (MQL) using canola oil and MQL using graphene blended in canola oil environment was discussed in this work. The tool wear and surface roughness were characterized to evaluate the textured tool's performance. It was revealed that the MQL (graphene mixed in canola oil) showed better results followed by MQL (only canola oil) and then dry condition. The excellent performance of graphene based MQL was mostly due to high thermal conductivity and shearing behavior of graphene. An increased shear angle (11–30%) and reduced coefficient of friction (16–39%) under graphene environment have contributed for enhanced performance of graphene-based MQL.

An Investigation on Turning AISI 1018 Steel with Hybrid Biodegradeable Nanofluid/MQL Incorporated with Combinations of CuO-Al2O3 Nanoparticles

Nanofluids are a group of fluids, which have been proven as an alternate to conventional cutting fluids. Using nanofluids in combination with Minimum quantity lubrication system have shown satisfactory results. For further improving the heat transfer capabilities of cutting fluids, hybrid nanoparticles were incorporated in the present work. A combination of CuO and Al2O3 hybrid nanofluids in various weight percentages (50:50, 25:75 and 75:25) were developed in-situ, with vegetable oil (Coconut oil) as basefluid. The machining tests were carried out on AISI1018 steel. The tool holders used was Kennametal beyond blast with ISO designation MCLNR2020K12BB and the inserts used were TiAlN coated beyond blast insert from kennametal with ISO designation CNGG 120408. The intent of this work was to find out the effect of hybrid nanofluids and machining parameters on surface roughness, while machining AISI 1018 steel. The results reported that with biodegradable hybrid nanofluids with CuO and Al2O3 (50:50) combination reduction of 13.72% in surface roughness.

Effect of TiO2 and Al2O3-ethylene glycol-based nanofluids on cutting temperature and surface roughness during turning process of AISI 1018

This paper presents the effect of TiO2 and Al2O3-ethylene glycol based nanofluids on cutting temperature and surface roughness during turning process of AISI 1018. Minimum quantity lubrication (MQL) method has been recognized in minimizing the usage of cutting fluid, as a step to achieve cleaner environment and sustainable machining. However, the low thermal conductivity of base fluid in minimum quantity lubrication system caused the insufficient removal of heat generated in cutting zone. Addition of nanoparticles to the base fluid was then introduced to enhance the performance of cutting fluids. In this study, the machinability of AISI 1018 (mild steel) was investigated under dry machining and nanofluid minimum quantity lubrication method. Two types of nanofluids (TiO2 and Al2O3 nanofluid) with concentration 0.05, 0.15 and 0.3 wt.% were used in this study. The experiments were conducted on lathe machine, using tungsten carbide as cutting tool. Three cutting speed (350, 550 and 750 m/min), three depth of cut (0.5, 1.0 and 1.5 mm) and fixed minimum quantity lubrication system nozzle pressure (5 bar) were applied throughout turning operation. To determine the relationship between machining parameters and cutting temperature and surface roughness values were measured. Based on results obtained, the cutting temperature of workpieces with usage of nanofluids in MQL system gave lower value compared to dry machining. The surface roughness of machined parts was also improved under NFMQL methods. In conclusion, when the nanofluid-MQL method was employed, the amount of cutting fluid was reduced and machining performance improved.

Enhancing Single Channel MQL through Bypass Controlled Design for Deep Hole Drilling with Small Diameter Tool

Because of significant energy savings, enablement of higher machining speed as well as environmentally friendly features, Minimum Quantity Lubrication (MQL) has been efficiently used for many machining processes. However, in deep hole drilling with small tools (tool diameter D< 5 mm and length L>25 D) there is a bottleneck for the single-channel MQL system. The single-channel MQL, based on the Venturi principle, has difficulty generating the required oil quantity due to dropped air pressure difference during the deep hole drilling process. In this paper, a system concept based on a bypass design is proposed and investigated in static and dynamic laboratory tests. In the static test, the oil volume with and without bypass control was measured. Through the spray pattern test, the aerosol distribution and the reaction time are analyzed. A dynamic machining trial with a drill tool (D=4.5 mm, L= 40 D) was carried out with the proposed system. The tool wear was tracked and analyzed up to 100 meters in drilling distance. The result shows that the single-channel MQL with a bypass control is able to overcome this limitation and enables a uniform and continuous aerosol flow to tooltips.

A new hybrid minimum quantity lubrication system for machining difficult-to-cut materials

A newly designed and manufactured hybrid MQL system is reported. Vegetable oil and tungsten disulphide suspension are mixed in an additively-manufactured nozzle and delivered through pressurised air as a coolant/lubricant spray. Cooling capability of the system is improved. Lubrication and the impact on machinability is assessed in high speed milling Ti6Al4V. Tool life and cutting forces with the new system are compared to those with air and with flood cooling and with commercial MQL. Over the reported practical range of cutting speeds, tool life is more than 2 times longer than with the commercial system and from 4 to 11 times longer than with air cooling.

Optimal Design of Parameters for the Nanofluid/Ultrasonic Atomization Minimal Quantity Lubrication in a Micromilling Process

Nanofluid/ultrasonic atomization minimal quantity lubrication (MQL) was used in an SKD11 steel micromilling process with ultrasonic dispersion. The nanofluid atomizer substantially improved nanofluid reunification and delivery to the cutting zone. The micromilling cutting force and temperature were used to calculate the signal-to-noise ratio (S/N). Normalization of the S/N in the gray relational analysis obtained a gray correlation coefficient, which is used in a fuzzy analysis to obtain a multiple performance characteristic indexes (MPCI). The MPCI is maximized by optimizing the process parameters for multiple quality characteristics and then comparing the optimized parameters with those in the MQL system. Experimental results indicate that the nanofluid parameters containing the density of nanofluid, feed rate, and distance of nozzle are the most influential control factors, while 3.617 N and 117.1 °C, respectively, are the best combination of parameters. Different lubricating methods are also compared in terms of effects on micromilling cutting force, micromilling temperature, micromilling tool wear, and surface burr. Experiments show that nanofluid multiwall carbon nanotube/ultrasonic atomization MQL obtained the best results.

Investigation on machining characteristics of TC4 alloy by simultaneous application of ultrasonic vibration assisted milling (UVAM) and economical-environmental MQL technology

Abstract The optimization of machining methods is one of important guiding principles for achieving high-quality, cost saving and environmental protection machining of difficult-to-machine materials in modern manufacturing. Considering the principles and advantages of ultrasonic machining (UM) method and minimum quantity lubrication (MQL) technique, the simultaneous application of UM and MQL methods is anticipated to further improve machining performance in terms of cutting force, surface quality and chip morphology. Theoretical analysis indicates that the MQL system in UVAM could provide enhanced lubrication and cooling performance because of the separate-type cutting mechanism, the surface acoustic and the cavitation phenomenon of resonant workpiece in UM. Conventional milling (CM) trials, general UVAM trials and combined UVAM&MQL trials were conducted to investigate the effect of UVAM and MQL methods on machining performance of TC4 alloy, where the results of CM and general UVAM could provide indispensable reference. Multifaceted comparisons are presented in machining results of CM, UVAM and UVAM&MQL trials in terms of time-domain analysis and frequency-domain analysis of milling force, average cutting force, surface topography, surface profile and surface roughness. The results show that cutting force features could be significantly affected under UVAM and UVAM&MQL condition compared with that in general milling due to intermittent cutting mechanism and the coupling effect of UVAM and MQL methods. The uniform micro-textured surfaces with improved profile fluctuations could be obtained when applying the UVAM&MQL strategy. Compared with surface roughness in CM and UVAM, the surface roughness in UVAM&MQL is improved by about 30–50% and about 20–30%, respectively. The excellent machining performance demonstrates the feasibility and effectiveness of simultaneously applying UVAM and MQL methods.

Correction to: Influence of dry and solid lubricant-assisted MQL cooling conditions on the machinability of Inconel 718 alloy with textured tool

Machinability of Ni-based aerospace alloy is considered to be difficult due to its numerous intrinsic properties. However, the machining performance of nickel-based alloys can be improved with the geometric alteration on the tool rake zone and by the proper cooling-lubrication mechanism. However, the complete consideration of the proper mechanisms is required. To fill this gap, the impact of cutting speed, machining time, and tool texturing was thoroughly inquired about along with cooling conditions on machinability indices such as tool wear, chip morphology, and cutting forces as well as surface finish. The machining tests were done with textured tools on Inconel 718 alloy at cutting speeds 80, 120, and 180 m/min respectively. Then, the comparison of machining characteristics with or without using solid lubrication mixed minimum quantity lubrication system were made. For that, the time of cutting was restricted to 10 min for comparison purposes. For machining at 80 and 180 m/min, the noteworthy reduction in flank and crater wear was observed, whereas at 120 m/min, small reduction is seen from 1 to 10 min under NFMQL condition. The surface roughness was found to be higher under a dry environment compared to a NFMQL environment due to the low coefficient of friction of MoS2 at a constant feed rate with an increase in cutting speed. The worst surface finish with maximum of 28.17% difference under dry machining condition was observed. It was clearly seen that the blend of canola oil mixed with MoS2 particles improved the cooling and friction at the cutting zone. In addition, analysis on the scanning electron microscope (SEM) has been done on the worn tools for better comprehension of tool wear during turning of Inconel 718 alloy. Finally, it has been reported that the performance of the textured tool under solid lubrication conditions is better to achieve a lower tool wear (Vb), surface roughness (Ra), cutting forces, and acceptable form of chips.

Sustainable machining of molds for tile industry by minimum quantity lubrication

Abstract Nowadays, to reduce water pollution, soil contamination, and human health hazards, the environmental legislation is forcing manufacturing companies to avoid the use of metalworking fluids. Thus, the adoption of the dry machining and minimum quantity lubrication (MQL) techniques is becoming essential. However, small and medium companies are having difficulties and are skeptical about the adoption of these new techniques. In this study, a methodology is proposed to implement an MQL system for sustainable machining with a step-by-step procedure that facilitates its industrial application. The methodology is divided into three steps: i) MQL configuration to verify its effect on surface roughness, considering the effective flow rates and nozzle position; ii) process modeling based on the Box–Behnken design of experiments (DoE) to model surface roughness, power consumption, and tool life; and iii) process optimization for minimizing cost and environmental impact in terms of water usage and kg of CO2 equivalent. The methodology is applied in the manufacturing process of a component of a mold for the tile industry. Different alternatives are analyzed and the best alternative in both economic and environmental aspects is the use of the MQL system with optimal cutting parameters and an early tool change strategy that ensures part quality without subsequent grinding operations.

Influence of minimum quantity lubrication in the surface quality of milled maraging steel

The use of large amount of cutting fluid in machining process represents a great environmental and economic issue. Minimum quantity lubrication (MQL) seems to be a feasible alternative to flood application as it reduces drastically the volume cutting fluid used in machining process. This paper investigated the relationship between cutting parameters and machined surface quality in the end milling of maraging 300 steel when flood and MQL methods were used. A full factorial design setting feed per tooth, cutting speed cutting depth, and fluid application technique was performed. Then, the effects of these parameters on machining forces, surface roughness, and residual stresses were studied by analysis of variance (ANOVA). The analysis of variance showed that the most important milling parameter regarding results of both surface roughness and residual stresses was the feed per tooth. Minimum quantity lubrication system was able to reduce machining forces for most of tested conditions, and surface roughness (Ra) was reduce in approximately 10%. Residual stress results showed that MQL is able to produce better results than flood method when low feed rate is used. It was found that the use of MQL technique is advantageous in the milling of maraging steel.

Efecto de parámetros de mínima cantidad de lubricación en reducción de desgaste de herramienta

The objective of this work is to determine the influence of Minimum Quantity Lubrication (MQL) parameters on flank wear during face milling. Furthermore, the values of each factor in which the MQL resulted to be effective were determined. A designed experiment with two level, three factor and two replicas was used to test tool wear on P45 grade inserts at relatively high cutting speed (~900 m/min) on steel AISI 1045. A commercial MQL system was used with vegetable base lubricant non soluble in water. Results show that amount of lubricant and vertical angle are key factors that affects the effectiveness of the process. A response surface equation was obtained in order to determine the zones in which the factors resulted in the lowest tool wear. A flank wear decrease of 7 times, respect to the maximum observed, was found by using low level of air flow, low level of vertical angle and high level of lubricant.

Influence of Different Cooling Methods on Tool Life, Wear Mechanisms and Surface Roughness in the Milling of Nickel-Based Waspaloy with WC Tools

Superalloys are generally considered to be difficult to machinability. In recent attempts to facilitate their machinability, minimum quantity lubrication (MQL) has been used due to its positive influence on cutting tool life, the environment and human health. This study focused on the tool life, wear behavior and surface roughness in the milling of nickel-based superalloy Waspaloy. Uncoated carbide tools, PVD (TiAlN)-coated tools and CVD (TiCN + Al2O3 + TiN)-coated tools were used. Experiments were performed with different cooling methods which included dry, wet and MQL. SEM and EDX were used for tool wear behavior and mechanism analyses. A portable measuring instrument and a 3D optical profilometer were employed for surface roughness analyses. Results obtained from the tests showed that during the milling of the Waspaloy, adhesion and abrasion were effective wear mechanisms for the cutting tools. The main wear behaviors were flank wear, crater wear and BUE (built up edge). In addition to these results, reduction in the tool wear, the wet machining and machining with the MQL system provided improvement at the rates of 37.54% and 29.01%, respectively, when compared to the dry machining.

A Framework for Integration of Internet of Things with Minimum Quantity Lubrication System

The aim of this paper is to provide a framework for the integration of internet of things with minimum quantity lubrication system during metal-cutting process, focusing to provide cleaner environment to manpower at shop floor. In last decade, minimum quantity lubrication system was studied and implemented effectively to optimize the metal cutting process at shop floor. Minimum quantity lubrication system was found to be most promising technique with respect to technical, economic and environmental aspects. Internet of things was also implemented in various domains of industry & delivered excellent outcomes. The internet of things has reduced production cost, cycle time and provides assistance to machine operator for improvement method insights. Thus, in this paper, prior research work of eminent investigators related to internet of things and minimum quantity lubrication were discussed and analysed. After review, it was found that if internet of things is integrate with minimum quantity lubrication system then it leads to new research area in the field of smart manufacturing. Internet of things-minimum quantity lubrication (IoT-MQL) integration provides a platform to automatic control the effect of cutting temperature generated during metal cutting process, due to which tool life and productivity affects significantly. This paper briefed an evaluation of manufacturing – socio based manual operation of minimum quantity lubrication system and propose scope for integration of it with internet of things for an economic and an environmental viewpoint. This investigation provides an outline of integration of internet of things with minimum quantity lubrication system. Proposed framework can be used to create an architecture based on lab-scale system with usually accessible, small cost electronic devices like sensors. Micro Electro-Mechanical System is the main base for this integrated framework of IoT-MQL system. This integrated framework represent a kind of key thing for empowering the ‘Smart Factory’ revolution.

Minimum Quantity Lubrication System for Metal-Cutting Process: Sustainable Manufacturing Process

Abstract The purpose of this paper is to deliver a review of the implementation of the minimum quantity lubrication (MQL) system for manufacturing method, centring on the application of the MQL during the metal-cutting of workpiece. The application of MQL system was implemented & studied by various eminent investigators in last two decades. Thus, in this paper, experimental investigations of prior research work were discussed and analysed to light on review with significant facts for investigators and industries to optimize the metal-cutting process. During metal-cutting process, previous investigators considered three independent parameters like cutting speed, depth of cut and feed rate. Out of these parameters, feed rate was found to be most influencing parameter for response variables. But, for specific metal-cutting operation specific types of feed rate is required. Hence, the selection of optimum value & type of feed rate for specific machining operation is yet to investigated. This paper explored an evaluation of industry-socio based trial and error approaches and propose scope for improvement from both an economic and an environmental viewpoint. This paper delivers an outline of formerly conducted analysis to propose zones of enhancement in metal-cutting process employing minimum quantity lubrication system

Development of an ultrasonic vibration assisted minimum quantity lubrication system for Ti-6Al-4V grinding

Minimum quantity lubrication (MQL) is widely used in machining/grinding as a competent cooling-lubrication technique owing to its advantages in terms of better cooling, lubrication, and lower coolant consumption. Ultrasonic vibration can be used to enhance the efficiency of MQL system by atomising the cutting fluid into fine and uniform droplets. In this study, an ultrasonic vibration assisted MQL (UAV-MQL) system is indigenously developed to effectively atomise the cutting fluid using the ultrasonic vibration of a suitably designed horn. To check the effectiveness of the developed UAV-MQL system, a set of experiments have been conducted on Ti-6Al-4V alloy during surface grinding operation, and the results have been compared with dry, flood and air-assisted conventional MQL grinding process using soluble oil as a cutting fluid.

Experimental study of magnesium drilling based on the surface quality

Nowadays, the use of magnesium and its alloys for transport applications is based on the combination of high mechanical properties and low density. In general, the machinability of these materials is considered to be good. Nevertheless, it has been reported that the machining of these alloys involves some critical problems regarding their tendency to be flammable at high temperatures and consequently, there is a risk of chip ignition in the working area during the process. This fact is especially critical when the size of chips is reduced. In this study, the influence of cutting conditions on surface roughness, in terms of Ra, obtained by drilling of magnesium alloy (AZ91D-F) was carried out. A factorial design 24 was employed for the planning of the drilling tests. The factors considered were the feed rate (0.05 and 0.2 mm/r), cutting speed, 40 and 60 m/min, the type of tool, in particular, the point angle of 118º and 135º, and the cooling system, Dry conditions and MQL (Minimum Quantity Lubrication) system. As main conclusions it can be affirmed that improved surface roughness is obtained with the cutting conditions selected in this study. Furthermore, at 0.05 mm/r and 40 m/min the use of tools with a point angle of 135º provides lower values of Ra than the tool of 118º point angle. Slightly lower values of Ra are obtained with tools of 118º point angle at 0.2 mm/r and 60 m/min.