Minimum Quantity Cooling Lubrication Research Articles

Effects of Machining Parameters of C45 Steel Applying Vegetable Lubricant with Minimum Quantity Cooling Lubrication (MQCL)

One of the most significant performance indicators for measuring the machinability of materials is tool wear and surface roughness. Choosing the best combination of cutting parameters can help reduce production costs, which is what the manufacturing industry is interested in. At the same time, industries are always looking for an alternative to conventional flood cooling since its use creates an environmental burden and health concerns for the operators. Therefore, vegetable oil-based minimum quantity cooling lubrication (MQCL) is considered a cutting environment. Sunflower oil is utilized as base fluid in MQCL and applied to the cutting zone through a nozzle. The turning experiments are conducted on C45 material which is widely used in various industrial applications, including numerous automotive components. Since flood cooling is widely utilized in machining C45, it is the present-day need to assess alternative cooling and lubricating approaches to avoid the adverse effects of flood cooling. The Taguchi method was used in the present work to minimize surface roughness and tool wear. L9 orthogonal array was constructed, and experiments were performed on C45 steel using coated carbide cutting tools. The statistical approach is utilized to evaluate the effect of cutting parameters on output responses. The optimal cutting settings for cutting speed, feed, and depth of cut to minimize surface roughness are 100 m/min, 0.18 mm/rev, 0.150 mm, and 80 m/min, 0.18 mm/rev, and 0.150 mm for tool wear. According to the findings, cutting speed, feed rate, and depth of cut varied surface roughness by 1.9%, 78.3%, and 14.04%, and tool wear by around 43.8%, 37.9%, and 6.3%, respectively. The outcomes can be useful to metal-cutting industries to identify the combination of machining parameters with vegetable oil-based MQCL.

Surface integrity investigation and multi-objective optimization in high-speed cutting of AISI 304 stainless steel for dry cutting and MQCL conditions

To realize green production in the manufacturing industry, it is important to reduce or even eliminate the discharge of cutting fluid. In this study, the impact tendency of the cutting parameters on the surface roughness of 304 steel was analyzed by establishing variance analysis models. The surface quality profile parameters and the main cutting force under minimum quantity cooling lubrication (MQCL) and dry cutting conditions were analyzed and compared. The characterization of the morphology of the machined surface was evaluated, and the wear mechanisms of the two machining methods were analyzed. A hybrid machining strategy was developed in which dry cutting is used at the beginning of cutting and dry cutting is replaced with MQCL before the quality of the machined surface deteriorates sharply. This strategy obtains the optimal parameter combination through a genetic algorithm. The most important factor affecting the surface roughness was the feed rate, whereas the change in cutting depth had no obvious effect on the surface roughness. In addition, the parameters of low cutting speed and feed rate were advantageous under dry cutting conditions. However, with increases in the feed rate and cutting speed, the peak and valley of the surface profile gradually increased, and the MQCL conditions were more conducive to obtaining a smoother surface. Furthermore, the MQCL and higher cutting speed could reduce the main cutting force. The surface roughness under hybrid cutting was 5.19% and 18.76% lower than that under MQCL and dry cutting, respectively.

Implementation of Sustainable Vegetable-Oil-Based Minimum Quantity Cooling Lubrication (MQCL) Machining of Titanium Alloy with Coated Tools

The lubrication capacity and penetration ability of the minimum quantity cooling lubrication-based strategy is linked with lubrication specific parameters (oil flow rates and air pressure), cutting conditions, and chip formation. It points out the complex selection involved in the MQCL-assisted strategy to attain optimal machining performance. Lubrication during metal cutting operations is a complex phenomenon, as it is a strong function of the cutting conditions. In addition, it also depends on the physical properties of the lubricant and chemical interactions. Minimum Quantity Lubrication (MQL) has been criticized due to the absence of cooling parts; MQCL is a modified version where a cooling part in the form of sub-zero temperatures is provided. The aim of this paper was to investigate the influence of different lubrication flow parameters under minimum quantity cooling lubrication (MQCL) when machining aeronautic titanium alloy (Ti6Al4V) using Titanium Aluminum Nitride—Physical Vapor Deposition (TiAlN-PVD) coated cutting inserts. The machining experiments on the MQCL system were performed with different levels of oil flow rates (70, 90, and 100 mL/h) and the performance was compared with the conventional dry cutting and flood cooling settings. A generic trend was observed that increasing the oil flow rate from 70—mL/h to 100 h/h improved the surface finish and reduced thermal softening at a low feed of 0.1 mm/rev. The results revealed that many tool-wear mechanisms such as adhesion, micro-abrasion, edge chipping, notch wear, built-up edge (BUE), and built-up layer (BUL) existed.

ON ONE ASPECT OF SUSTAINABLE MANUFACTURING Power Consumption vs Productivity

The paper presents one aspect of the analysis of energy consumption and productivity of the manufacturing operation. As an example of the operation, the operation of turning with a single-blade tool was taken. Sustainable development in its general concept implies sustainable materials, sustainable design, and sustainable manufacturing. This paper presents an analysis of one important part of sustainable manufacturing, and that is energy saving. The experimental study was conducted as follows. In laboratory conditions, an experimental-mathematical regression model of the relationship between cutting force and processing conditions was defined. Machining experiments were performed under ECO-friendly conditions with technology known as MQCL (Minimum Quantity Cooling Lubrication) machining. The obtained mathematical model was used to calculate the energy consumption and the workpiece material removal rate (MRR, productivity). The results of the analysis showed that there is a lot of space for optimization of machining conditions from the aspect of power consumption, with mandatory calculation and other machining costs, above all, the cost of tools and machine tools. In this regard, recommendations for analysis with the aim of power saving are given.

Optimization of process parameters in micro milling of Ti4Al4Mo2Sn using nano Al2O3 additives based minimum quantity cooling lubrication

ABSTRACT. Aerospace and automotive industries employ Ti4Al4Mo2Sn material in many applications due to its properties of better strength to weight ratio and high corrosion resistance. Ti4Al4Mo2Sn finds itself difficult to cut materials due to its physical and chemical properties and is prone to more heat generation during machining. The more generation of heat affects the machined material surface quality and other related properties. In this investigation, the thermal conductivity and stability of Al2O3/Water based nanofluids are studied to select the best composition of nanofluid for transferring heat. The thermal conductivity and stability of the nanofluid for a duration of 30 days are computed by employing the KD2 thermal property meter and pH meter, respectively. Thermal conductivity and stability of the Water/4.5 vol.% Al2O3 nanofluid are found to be better than other combination of nanofluids. In the present study, optimizing the micro milling process parameters on Ti4Al4Mo2Sn material with Minimum quantity cooling lubrication (MQL) is focused. The input parameters selected for this micro milling process are spindle speed, feed rate, depth of cut and Water/4.5vol.% Al2O3 nanofluid and the output parameters selected are cutting forces in X(Fx) and Y(Fy) directions, tool wear rate (TWR) and surface roughness (SR). The optimization is done with the help of grey relational analysis (GRA) by using L9 Orthogonal Array (OA) Taguchi design. The obtained sequence of influencing parameters are feed rate per tooth, Al2O3nanofluid, spindle speed and depth of cut. The percentage of grey relational grade (GRG) for prediction and experimental is 0.721 and 0.957. The percentage of improvement of GRG is 12.46.
 
 KEY WORDS: Ti4Al4Mo2Sn, Al2O3, Thermal conductivity, Grey relational analysis, Grey relational grade
 
 Bull. Chem. Soc. Ethiop. 2022, 36(2), 339-351. 
 DOI: https://dx.doi.org/10.4314/bcse.v36i2.8

Investigation of Machining Performance of MQL and MQCL Hard Turning Using Nano Cutting Fluids

Cutting fluids used in the metal machining industry have exerted serious impacts on the environment and human health. In addition, the very high cutting heat and forces in machining-hardened steels have been a growing concern in the metal cutting field. Hence, new, eco-friendly cooling and lubricating techniques are necessary to study and develop. Minimum quantity lubrication (MQL) and minimum quantity cooling lubrication (MQCL) using nano cutting fluids have been proven as alternative solutions for machining difficult-to cut materials while retaining an environmentally friendly characteristic. Accordingly, this paper aims to analyze and evaluate the hard turning efficiency of 90CrSi (60 ÷ 62 HRC) steel using MQL and MQCL conditions, using Al2O3 and MoS2 nano cutting fluids. The 2k-p experimental design and analysis of variance (ANOVA) were used to study the influence of input parameters including fluid type, lubrication method, nanoparticle type, nanoparticle concentration, cutting speed and feed rate on surface roughness. The obtained results showed that the machinability of CNMG120404 TM T9125 carbide tools was improved and the highest machinable hardness was increased from 35 HRC to 60 ÷ 62 HRC (rising by approximately 71.4 ÷ 77.1%) by using the nanofluid MQL and MQCL methods. Furthermore, MQCL gives better performance than MQL, and the Al2O3 nanofluid exhibits the better result in terms of surface roughness values than the MoS2 nanofluid. Feed rate displays the strongest influence on surface roughness, while fluid type, nanoparticle concentration and cutting speed show low impacts. From these results, technical guidance will be provided for further studies using Al2O3 and MoS2 nano cutting fluids for MQL and MQCL methods, as well as their application in machining practice.

Effect of cutting edge radius on end milling Ti–6Al–4V under minimum quantity cooling lubrication – Chip morphology and surface integrity study

The effect of cutting edge radius (30–55 μm) during milling Ti–6Al–4V under minimum quantity cooling lubrication (MQCL) conditions is studied. A trial study is conducted to compare the performance of dry, wet, and MQCL using unprepared tools with edge radius of 30 μm alone. Subsequently, inserts having initial radius of 30 μm are prepared to 40–55 μm radius using drag finishing and milling of Ti–6Al–4V under MQCL is studied for different edge radii. Rounded edge tools are found to produce thinner and more curvilinear chips resulting in easier chip removal from the machining zone. The chip thickness and curl radius were up to 54% and 47% lower for the larger edge radius tools as compared to the 30 μm edge radius tool. This improves the penetration of the MQCL aerosol jet into the cutting zone thus producing better tribological results. The better penetration of MQCL aerosol into the cutting zone for larger edge radius tools results in lowering the resultant process forces (up to 16%), tool-chip interface temperature (15%), tool wear (40%) and surface roughness (30%) for the 48 μm radius tool as compared to the unprepared (30 μm) tool. There is deterioration in process forces, tool wear and surface integrity for the 55 μm tool possibly suggesting the existence of an optimum edge radius closer to 48 μm.

Novel Uses of Al2O3/Mos2 Hybrid Nanofluid in MQCL Hard Milling of Hardox 500 Steel

In recent years, the application of environmentally friendly cutting fluids in the metal cutting industry has been a growing concern in all over the world. In this study, the minimum quantity cooling lubrication (MQCL) technique, which uses very small amount of cutting oil, is motivated to apply to the hard milling process of Hardox 500 steel. Further, rice bran oil, a natural biodegradable oil, is used as the base fluid of Al2O3/MoS2 hybrid nanofluid. ANOVA analysis is used to study the influences of nanoparticle concentration, cutting speed, and feed rate on surface roughness. The obtained results indicate that good surface quality is achieved and the cutting speed is significantly increased to 140 m/min (about 2.55–2.80 times higher than the recommended values) due to the better cooling and lubricating effects from MQCL system and Al2O3/MoS2 hybrid nanofluid. Moreover, the microstructure of the machined surface proves the formation of MoS2 tribo film by using Al2O3/MoS2 hybrid nanofluid, indicating that the effectiveness of each type of nanoparticle in hybrid nanofluid has been promoted. Furthermore, the important technical guides for machining Hardox 500 steel are provided.

Study on vibration and surface roughness in MQCL turning of stainless steel

Abstract Minimum quantity cooling lubrication (MQCL) is an alternative to the conventional flood cooling method, which satisfies ecofriendly and low-cost requirements. In this study, the full-factorial experimental method of machining AISI 304 steel under MQCL and flood cutting conditions were investigated to evaluate the surface quality and tool vibration. The surface roughness characteristics were analyzed using the power spectral density, and vibration and surface roughness models were predicted using the response surface methodology. Finally, simulated annealing and particle swarm optimization were combined to optimize the process parameters. The results revealed that a decrease in the surface roughness and vibration occurred under MQCL conditions. The feed rate significantly influenced the surface roughness, axial vibration, and radial vibration, and their corresponding contributions were 69.8 %, 63 %, and 51.05 %, respectively. With an increase in the cutting speed, the vibrations and surface roughness decreased. However, the cutting depth did not significantly influence surface roughness. The low-frequency vibration of the surface profile resulted in the formation of grooves and ripples. Therefore, the optimized cutting parameters, minimum surface roughness, and vibration could be obtained.

Cutting tool wear in turning 316L stainless steel in the conditions of minimized lubrication

316L stainless steel has emerged as one of the most used material in design and manufacturing for automotive, aerospace, marine, civil nuclear to produce critical components (valves, seats, pipes etc.). Despite, their huge application, during the machining of 316L stainless steel numerous challenges arise in terms of tool wear that are very detrimental for the surface of machined part. To obtain an extended life of tool used for machining commonly 316L stainless steel two different methods of cooling based on minimum lubrication condition, namely Minimum Quantity Lubrication (MQL) method and Minimum Quantity Cooling Lubrication (MQCL) with the addition of extreme pressure and anti-wear (EP/AW) method, respectively were settled. The use of the MQL method resulted in a reduction of the cutting tool wear by approximately 9% compared to the MQCL + EP/AW method and by approximately 21% compared to dry machining. Further, the highest values of wear indices were achieved during dry machining and the lowest ones in the method of minimized lubrication which validate the minimum lubrication as beneficial for reducing the wear progress.

Surface generation in ultrasonic-assisted high-speed superabrasive grinding under minimum quantity cooling lubrication with various fluids

Ultrasonic assisted grinding (UAG), and minimum quantity cooling lubrication (MQCL) have individually improved grinding characteristics of difficult–to-cut super-alloys in terms of reduced forces and surface roughness. In the present work, a hybrid grinding approach (UAG + MQCL) is utilized, and the effect of fluid's lubricity on grit-workpiece interaction has been investigated during the grinding of Ti–6Al–4V. More lubricious fluid provided less resistance to vibration transfer to the grinding zone, and consequently, the effective amplitude of vibration increased with an increase in lubricity of the fluids. It has governed the mechanism of grinding scallop formation significantly. Additionally, more lubricious vegetable oil yielded the lowest grinding power and higher compressive residual stress. Further, 20–100% improvement in compressive residual stress was noted under UAG.

Tool Wear and Temperatures Analysis While Machining Ti-6Al-4V in MQCL-MIST Environment

Sustainable machining of titanium alloys have deficiency of studies on the built-up edges over the cutting tools and temperature correlation in minimum quantity cooling lubrication (MQCL) environment. Researchers focused on experimentation in dry, wet, and MQL (minimum quantity lubrication) conditions to analyze surface finish, cutting forces, and metal removal rates. This work focuses on the study of cutting parameters effects on temperatures and tool wear analysis by consideration of individual response and their optimality basing on signal-to-noise ratios. Efficacy of process parameters on wear of tool and temperatures requires a comprehensive understanding. An elaborated tool wear analysis is carried based on the microscopic flank wear investigations. Machining of Ti-6Al-4V alloy is carried in the environment of MQCL in form of mist using semi-synthetic fluid. Correlation study of tool wear with regard to temperatures is analyzed and regression models generated on tool wear and cutting temperatures individually showed 83% of goodness-of-fit and correlation regression is 85%.

Wear mechanism in high-speed superabrasive grinding of titanium alloy and its effect on surface integrity

Single-layer electroplated cBN wheels offer several advantages over conventional wheels when grinding difficult-to-cut materials, in terms of improved workpiece surface integrity issues, such as lower grinding burn, fewer surface defects, and generation of compressive residual stresses. However, grinding behaviour e.g., grinding forces, temperature, and surface integrity, changes with wheel use while employing single-layer wheels due to progressive wheel wear as dressing is not conducted for them. Therefore, wheel wear and associated grindability studies like grinding forces and surface integrity are essential for the implementation of these wheels in the industry. The present study evaluates the wear mechanism of the electroplated cBN wheel and its effect on the grindability of Ti–6Al–4V. High grinding speeds (40 & 60 m/s) were employed under different cutting fluids environments (water-based soluble oil emulsion in minimum quantity cooling lubrication (MQCL) as well as in flood cooling modes and neat oil in MQCL regime). A lower cutting speed of 20 m/s is also chosen for benchmarking purpose. Grit fracture is found to be the primary mode of wheel wear. An elaborate discussion on the mechanism of cBN grit fracture is presented. It is observed that thermal shock-induced fracture has a dominant effect on wheel wear, and consequently, water-based fluid provided 2–4 times higher radial wear than neat oil up to 40 m/s. Because of lower radial wear, neat oil provided only 0–10% increase in grinding forces, 0–10% decrease in compressive residual stress, and almost the same level of surface redeposition with the progression of cumulative material removal. On the other hand, water-based fluid yielded 30–100% rise in grinding forces, 10–75% decrease in compressive residual stress, and a higher level of surface redeposition.

Improvement in the Hard Milling of AISI D2 Steel under the MQCL Condition Using Emulsion-Dispersed MoS2 Nanosheets

The present work shows the process for MoS2 nanosheet production by liquid N2-queched bulk, a novel method having highly efficient, green, and facile operation. The produced MoS2 nanoparticles are suspended in minimum quantity cooling lubrication (MQCL)-based fluid to form nanofluid used for the hard milling of AISI D2 steel. The study aims to improve the hard-milling performance assisted by the MQCL technique using MoS2 nanofluid. ANOVA analysis is used to evaluate the effects of three input machining variables, including nanoparticle concentration, cutting speed, and material hardness on cutting forces. The results indicate that the better cooling effect from the principle of the Ranque–Hilsch vortex tube of the MQCL device combined with the better lubricating performance from MoS2 nanofluid brings out the sustainable alternative solution for machining difficult-to-cut material. Moreover, the experimental results provide the technical guides for the selection of proper values of nanoparticle concentration and cutting speed while ensuring the technological, economic, and environmental characteristics.

Evaluation of turning with different cooling-lubricating techniques in terms of surface integrity and tribologic properties

This research presents the analysis of metrologic and tribologic aspects of machined surfaces obtained after turning with the application of various cooling/lubricating methods. The thoroughly conducted machining tests are: dry machining, minimum quantity cooling lubrication (MQCL); minimum quantity cooling lubrication with EP/AW modifications (MQCL+EP/AW) and minimum quantity lubrication (MQL). The phosphate ester based modification in the MQCL+EP/AW method is employed in order to increase the lubricating properties of the emulsion. The surface topography, responsible for the tribological properties of mating parts, is measured. The smallest values of the surface roughness are obtained after turning under MQCL+EP/AW conditions, while the highest values of parameters responsible for oil retention in mating parts are obtained after machining with the MQL method.

Effect of metal cutting fluid (MCF) conditions on tool wear and thrust force in drilling Ti-6Al-4V using coated carbide tools

Titanium alloy (Ti-6Al-4V) is well known as difficult to cut material due to their low machinability rating. Machining Ti-6Al-4V generate high cutting temperature close to the cutting edge of the tool. The high cutting temperature, mostly during the deformation process and friction at the tool–chip and tool–workpiece interfaces. This circumstances will lead to the rapid tool wear. This study focuses on the growth of tool wear and development of the thrust force. Drilling tests were conducted using coated (TiAlN) carbide tool with diameter of 6 mm under two different condition of metal cutting fluid (MCF). The MCF used were minimum quantity lubrication (MQL) and minimum quantity cooling lubrication (MQCL). The outcomes of this study indicates MQL performed better coolant-lubricant effect during drilling Ti-6Al-4V as the results of thrust force development are consistent with the trends of tool wear growth.

Effect of cutting parameters on tool wear under minimum quantity cooling lubrication (MQCL) conditions

This paper presents the effect of cutting parameters on tool wear under minimum quantity cooling lubrication (MQCL) conditions. Turning AISI 304 stainless steel was carried out using VAMF-1 environmentally friendly cutting fluid under MQCL conditions, for which 27 groups of all-factor experiments were utilized. The tool wear results showed that the most effective parameter was the cutting speed (relative contribution of 46.725%), followed by the feed rate (relative contribution of 28.120%). According to the tool vibration results, the cutting speed was the most important parameter, followed by the feed rate and the cutting depth. During low-speed cutting, a larger feed rate and cutting depth could be selected, for which adhesive wear is the prevailing mechanism. As the cutting speed increased, the built-up edge (BUE) near the cutting edge disappeared and the adhesives fell off; diffusion wear was the main mechanism in this case. In addition, a prediction model was constructed with the objective of surface finish and tool wear, and the results were optimized by an improved fruit fly optimization algorithm (FOA). The verification experiment results showed that the prediction errors of VB and Ra were 2.15% and 6.48%, respectively. Moreover, MQCL achieved better surface quality and lower tool wear than minimum quantity lubrication (MQL) and dry cutting under the optimized parameters.

Performance Evaluation of MQCL Hard Milling of SKD 11 Tool Steel Using MoS2 Nanofluid

The present work shows an experimental investigation on the effect of minimum quantity cooling lubrication (MQCL) during hard milling of SKD 11 tool steel (52–60HRC). The novelty here lies on the use of MQCL technique, which comprises the cooling strategy based on the principle of Ranque-Hilsch vortex tube and MQL method. Moreover, MoS2 nanoparticles are suspended in MQCL based fluid to improve the lubricating character. The response parameters, including surface roughness, surface microstructure, and surface profile are studied. The obtained results show that MQCL using nanofluid gives out better surface quality compared to dry, MQL, and MQCL with pure fluid. Also, the different concentrations of MoS2 nanoparticles are investigated to find out the optimized value as well as the interaction effect on machined surface.

Effect of cutting fluids applied in MQCL mode on machinability of Ti-6Al-4V

This paper experimentally investigates the role of minimum quantity cooling-lubrication (MQCL) with soluble oil, aqueous alumina and hBN nanofluids in turning of Ti-6Al-4 V. The effect of various machining environments has been studied on different machinability characteristics like all the three components of cutting forces, state of effective lubrication at the chip-tool interface, different tool wear parameters and adhesion of work material on the rake surface. The concept of cumulative machinability index has been used to analyze the role of machining environments. Soluble oil when applied in MQCL mode provided the best performance due to a much better state of effective lubrication at the chip-tool interface. Flood cooling with the same soluble oil could not provide comparable performance mainly due to its poor reachability at the chip-tool interface. Aqueous nanofluids also could not compete with soluble oil applied in MQCL mode mainly due to the intimate nature of contact and high cutting temperature at the chip-tool interface in turning of Ti-alloys.

Recent Advances in the Machining of Titanium Alloys using Minimum Quantity Lubrication (MQL) Based Techniques

Titanium alloys are generally known as difficult-to-machine materials because of their low machinability ratings. Their usage is favored for demanding sectors because of their high strength to weight ratio, high corrosion resistance and ability to operate at elevated temperatures. Machining of titanium alloys results in higher environmental burden, because they require high energy and generous amount of cutting fluids during machining. It is a well-known fact that most of the cutting fluids are toxic and non-biodegradable in nature and their disposal is costly. Therefore, researchers in metal cutting are keen to explore the potential of minimum quantity lubrication (MQL) and minimum quantity cooling lubrication (MQCL) based cooling techniques as an alternate to conventional flood cooling. When MQL and MQCL techniques are used by employing biodegradable vegetable based oils then there is an encouraging potential of replacing the non-biodegradable cutting fluids. This study documents the recent experimental and numerical advances achieved in the MQL and MQCL assisted techniques for machining titanium alloys. The study also highlights the current challenges in this area and recommends future work to address these challenges.