Nano-cutting Fluids Research Articles

Novel application of graphite-talc hybrid nanoparticle enriched cutting fluid in turning operation

In this study, the influence of hybrid nanocutting fluid (both graphite and talc nanoparticles dispersed in a base fluid) in turning of Titanium alloy grade 5. The hybrid nanocutting fluid was developed by the blending of graphite and talc nanoparticles in a constant volumetric proportion (50:50) in pure coconut oil as a base fluid. The prepared hybrid nanocutting fluid has been investigated for its tribological behaviour using a pin-on-disc machine. The Gray relational analysis (GRA) is applied as a conservative approach in the optimization of process variables of Titanium alloy with multiple performance characteristics. The turning performance of the hybrid nanocutting fluid is compared with that of pure coconut oil in terms of cutting force and surface roughness. From the Gray relational grade analysis, it is obtained that the feed rate has a larger influence on responses as compared to cutting speed and nanoparticle concentration as well. By the application of hybrid nanocutting fluid, it is obtained a significant reduction in cutting force and surface roughness compared to pure coconut oil by 21.19 % and 18.9 %, respectively.

Environmental Analysis of Sustainable and Traditional Cooling and Lubrication Strategies during Machining Processes

Due to rising demands of replacing traditional cooling strategies with sustainable cooling strategies, the development of sustainable strategies such as minimum quantity lubrication (MQL) of nano-cutting fluids (NCFs) is on the rise. MQL of NCFs has received a lot of attention due to its positive impact on machining process efficiency. However, environmental and human health impacts of this strategy have not been fully investigated yet. This work aims to investigate the impacts of MQL of molybdenum disulfide (MoS2), multi-walled carbon nanotubes (MWCNTs), titanium dioxide (TiO2), and aluminum oxide (Al2O3) NCFs by employing a cradle-to-gate type of life cycle assessment (LCA). Besides, this paper provides a comparison of the impacts and machining performance when utilizing MQL of NCFs with other cooling strategies such as traditional flood cooling (TFC) of conventional cutting fluids and MQL of vegetable oils. It was found that NCFs have higher impacts than conventional cutting fluids and vegetable oils. The impacts of TiO2-NCF and MoS2-NCF were lower than the impacts of MWCNTs-NCF and Al2O3-NCF. MQL of NCFs presented higher impacts by 3.7% to 35.4% in comparison with the MQL of vegetable oils. TFC of conventional CFs displayed the lowest impact. However, TFC of conventional cutting fluids is contributing to severe health problems for operators. MQL of vegetable oils displayed higher impacts than TCFs of conventional cutting fluids. However, vegetable oils are considered to be environmentally friendly. According to the findings, the MQL of vegetable oils is the most sustainable strategy for machining processes with associated low/medium cutting temperatures. While MQL of TiO2 and MoS2 NCFs are the sustainable strategy for machining processes associated with high cutting temperatures.

Studies on chip morphology and modes of tool wear during machining of Ti-6Al-4V using uncoated carbide tool: application of multi-walled carbon nanotubes added rice bran oil as nanocutting fluid

In this work, machining performance of Ti-6Al-4V is studied in consideration with cutting force, tool-tip temperature, tool wear mechanisms, chip morphology and roughness of the machined surface. Machining experiments are carried out by varying cutting speed (Vc) with constant feed and depth-of-cut. Uncoated WC-Co insert is used as cutting tool. Multi-walled carbon nanotubes (MWCNTs) added rice bran oil is utilized to produce nanofluid minimum quantity lubrication (MQL) environment. Chip morphology along with measurable geometrical parameters including chip-tool contact length, equivalent chip thickness (H ch), segmentation spacing, segmentation frequency, shear band width, shear angle, chip hardness, etc. are studied in detail. Effects of Vc on cutting force, tool-tip temperature, depth of flank wear, and area of crater wear are discussed. Different tool wear mechanisms are identified as well. It is experienced that nanofluid MQL (NFMQL) outperforms traditional dry cutting as well as conventional MQL in purview of improved process performance.

Experimental investigations on surface integrity and chip morphology in hard tuning of AISI D3 steel under sustainable nanofluid-based minimum quantity lubrication

Efficient cooling and lubrication techniques are required to obtain sustainable machining of difficult-to-cut materials, which are the pillars of aerospace, automotive, medical and nuclear industries. Excessive cutting fluid is required and consumed in machining difficult-to-machine materials with high-pressure coolant supplies. Nanofluid-assisted minimum quantity lubrication (NFMQL) is adorned with improved machining performance and environmental sustainability. The present work addresses the surface integrity and chip morphology in finish hard turning of AISI D3 steel under NFMQL condition. The surface integrity aspects include microhardness, residual stress, white layer formation, machined surface morphology, and surface roughness. This experimental investigation aims to explore the feasibility of low-cost multilayer (TiCN/Al2O3/TiN) coated carbide tool in hard machining applications and to assess the propitious role of minimum quantity lubrication using graphene nanoparticles with enriched radiator coolant-based nano-cutting fluid for machinability improvement in hardened steel. Combined approach of central composite design—analysis of variance, desirability function analysis, and response surface methodology, has been subsequently employed for experimental investigation, predictive modelling, and optimization of surface roughness. With a motivational philosophy of “Go Green-Think Green-Act Green”, the work also deals with economic analysis and sustainability assessment under environmental-friendly NFMQL condition. It is expected that the found optimized parameters can contribute to machining end-outcomes such as an improved surface finish and reduced machining cost. The results showed that machining with NFMQL provided an effective cooling–lubrication strategy, safer and cleaner production, environmental friendliness and assisted in improving sustainability. In conclusion, the proposed NFMQL turning strategy is a robust method validated by statistical analysis for large industrial applications, especially in mould and die making sectors.

Modeling and Optimization of Power Consumption for Economic Analysis, Energy-Saving Carbon Footprint Analysis, and Sustainability Assessment in Finish Hard Turning Under Graphene Nanoparticle–Assisted Minimum Quantity Lubrication

The present work addresses the issue on power consumption in finish hard turning of die steel under nanofluid-assisted minimum quantity lubrication condition. This study also aims to assess the propitious role of minimum quantity lubrication using graphene nanoparticle-enriched radiator green coolant-based nano-cutting fluid for machinability improvement of hardened steel. The hard turning trials are performed based on design of experiments by considering the geometrical parameters (insert’s nose radius) and machining parameters (cutting speed, axial feed, depth of cut). Combined approach of central composite design—analysis of variance, desirability function analysis, and response surface methodology—have been subsequently employed for analysis, predictive modeling, and optimization of machining power consumption. With a motivational philosophy of “Go Green-Think Green-Act Green”, the work also deals with energy-saving carbon footprint analysis, economic analysis, and sustainability assessment under environmental-friendly nanofluid-assisted minimum quantity lubrication condition. Results showed that machining with nanofluid-minimum quantity lubrication provided an effective cooling-lubrication strategy, safer and cleaner production, environmental friendliness, and assisted to improve sustainability.

Dry, MQL, and Nanofluid MQL Machining of Ti–6Al–4V Using Uncoated WC–Co Insert: Application of Jatropha Oil as Base Cutting Fluid and Graphene Nanoplatelets as Additives

Nanocutting fluids are very popular due to their excellent thermo-physical and tribological properties which provide adequate cooling and lubrication during metal cutting. Conventional dry machining of difficult-to-cut superalloy Ti–6Al–4V faces several challenges. To overcome this, application of cutting fluid is indeed a necessity. However, performance of conventional minimum quantity lubrication (MQL) system, in which air–oil mist is sprayed into cutting zone, is somewhat limited due to inadequate penetration into tool–work and tool–chip interfacial regions, especially at high cutting speeds. MQL performance can further be enhanced by applying nanocutting fluid in which nano-sized additives are dispersed into the base cutting fluid; this is known as nanofluid MQL (NFMQL). In order to take care of several alarming issues related to environmental protection and occupational health hazards, the present study explores application feasibility of biodegradable Jatropha oil added with graphene nanoplatelets as nanocutting fluid. Machinability of Ti–6Al–4V is assessed under NFMQL; results are compared to that of dry and conventional MQL machining. Cutting force magnitude, tool-tip temperature, morphology of worn-out insert, chip’s macro/micro-morphology and surface roughness of the machined work part, etc., are studied in detail. For MQL and NFMQL, tool wear morphology detects existence of ‘unaffected zones’ which indicates sustenance of strong hydrodynamic tribo-film of cutting fluid, thus protecting the insert against wear. Up to 82 m/min cutting speed, NFMQL causes lower tool flank wear than dry and conventional MQL. On the other hand, superior machined surface finish is obtained under NFMQL up to 106 m/min cutting speed.

Performance evaluation of MQL with AL2O3 mixed nanofluids prepared at different concentrations in milling of Hastelloy C276 alloy

Since some deficiencies in mist lubri-cooling techniques i.e., minimum quantity lubrication (MQL) in heavy cutting conditions have been noticed, recently nano-cutting fluids which have enrich thermal conductivity than base fluid, are begun to be used in MQL system. One of the critical issues arising in this process is the addition of the appropriate nanoparticle ratio to the base liquid. Therefore, this study aimed to find the optimum distribution rate of Al2O3 nanoparticles having excellent properties and machining parameters. For this purpose, by adding Al2O3 nanoparticles to vegetable-based cutting fluid, nano-cutting fluids were prepared in different volumetric concentrations (0.5, 1.0 and 1.5 vol%). These prepared nanofluids were used in the MQL system when milling of Hastelloy C276. Three cutting speeds (60, 75 and 90 m/min) and three different feed rates (0.10, 0.15 and 0.20 mm/rev) were added to the experimental design to study the performance of nanofluids under several cutting parameters. Apart from this experimental design, to clearly see the effect of concentration rates on tool wear and tool life, three experiments were carried out at each concentration ratio by keeping the machining parameters. Eventually, 1 vol% Al2O3 concentration clearly provided an improvement by up to 23% and 10% in tool life, compared to 0.5 vol% and 1.5 vol% concentration, respectively. In addition, while chipping/fracture, attrition wear and peeling of coating were observed under all cutting conditions, there was no evidence for workpiece material adhesion at 1 vol% and 1.5 vol% Al2O3 based nanofluid-MQL.

Tribological mechanisms of nano-cutting fluid minimum quantity lubrication: a comparative performance analysis model

The nano-fluid system efficiency is mostly governed by the amount, structure, and characteristics of the nano-additives and the mechanism by which the nano-fluids are distributed and sprayed to the tool–workpiece interface zone. The utilization of nano-additive-based cutting fluid demonstrated significant improvement in the wear behavior of the cutting tool. They also provide excellent cooling capabilities when machining is carried out at high temperatures especially when cutting difficult-to-machine workpiece material. The present study offers an in-depth study aided with solid analysis and interpretation for the tribological phenomenon associated with the nano-cutting fluids. In the current study, a relative wear volume model has been proposed and validated for two nano-cutting fluid cases. The presented model reveals that nanotubes offer less induced abrasive wear in comparison with the nanoparticles (i.e., the ratio between the induced nanoparticles wear to the nanotubes wear ranges from 139 up to 360 when the applied forces ranges from 10 up to 3000 N, respectively). To validate the model findings, machining experiments were carried out on Inconel 718 under nano-cutting fluid minimum quantity lubrication (MQL) with different cutting parameters and nano-additive concentrations. Two nano-additives performance have been worked out with the MQL conditions, namely, alumina nanoparticles (Al2O3) and multi-walled carbon nanotubes (MWCNTs). The wear on the flank face is determined for each cutting run to evaluate the performance of both nano-cutting fluids. The model estimates found to be consistent with the experimental findings as as MWCNTs showed less tool wear compared with Al2O3 (i.e., varied from 2 up to 150% at different cutting speeds and feed rates).

Testing of Nanofluids and Their Machining Performance Evaluation

Abstract This paper is an attempt to evaluate the thermophysical properties and performance of vegetable oil–based nano-cutting fluids while turning American Iron and Steel Institute (AISI) 1040 steel. Nano boric acid particles in different proportions (0.25, 0.5, 0.75, 1, and 1.25 % w/w) are dispersed in coconut oil. The nano-cutting fluids thus formulated are tested for density, thermal conductivity, and dynamic viscosity. Empirical relations are used to evaluate specific heat and heat transfer coefficients. These nanofluids are then applied during machining through minimum quantity lubrication technique. Microbial contamination and biodegradability tests are conducted to assess the quality of nano-cutting fluids. It is observed that the contribution of depth of cut is 46 % and the contribution of nanoparticle inclusions (NPI) is 31.29 % in minimizing the cutting temperatures. Optimum machining performance is influenced mainly by NPI followed by depth of cut, cutting speed, and then feed rate.

Machinability of Ti–6Al–4V Superalloy: Performance of Dry Cutting and Nanofluid MQL (MWCNT-Added Rice Bran Oil)

The present work shows the study of machining performance of Ti–6Al–4V under nanofluid minimum quantity lubrication (NFMQL) condition. Commercially available rice bran oil is used as base cutting fluid, in which multi-walled carbon nanotubes are added to prepare nanocutting fluid. Dominant tool wear mechanisms are identified. Influence of machining duration on evolution of cutting force, approximate tool-tip temperature, progression depth of flank wear, area of crater wear, workpiece surface roughness, etc., is studied in detail and compared to that of dry machining (without coolant). Chip morphological (macro/micro) study is also carried out. It is experienced that NFMQL performs better than traditional dry cutting. When compared to dry machining, NFMQL results in 62.7%, 8.69%, 42%, and 12.8% reduction in tool-tip temperature, tangential component of cutting force, depth of flank wear, and product surface roughness, respectively.

Effect of Vegetable Oil–Based Hybrid Nano-Cutting Fluids on Surface Integrity of Titanium Alloy in Machining Process

Abstract In the present work, an attempt is made to examine the machining performance in turning titanium alloy using vegetable oil–based hybrid nano-cutting fluids. The sesame oil–based hybrid nanofluids with carbon nanotubes (CNT)/molybdenum disulphide (MoS2) in the ratio of 1:2 are used to test the effect of surface integrity in the machining of titanium alloy. The cutting forces, cutting temperatures, surface roughness, and microhardness of the machined surface were measured. The machined surface is analyzed for machining-induced residual stresses and changes in the surface topography. Machining performance improved with vegetable oil–based hybrid nano-cutting fluids in reducing cutting forces and cutting temperatures. The percentage reduction of temperatures in the cutting zone under 0.5, 1, 1.5, and 2 wt. % and conventional cutting fluids (CCFs) are 70.2, 58.2, 63.1, 67.3, and 56.7, respectively, compared with dry machining. The percentage reduction in cutting forces are found to be 39.4, 70.9, 42.7, 73.2, and 72.3 for CCF 0.5, 1, 1.5, and 2 wt. % nanoparticle inclusions (NPI) compared with dry cutting, respectively. The percentage reduction in surface roughness (Ra) under CCF is 9.6, 24.4, 23.2, 22.4, and 26.7 for 0.5, 1, 1.5, and 2 wt. % NPI respectively, compared with dry cutting. The microhardness of the machined surface increased, and residual stresses are encouraging with hybrid nano-cutting fluids.

Effects of cutting fluids with nano-silver and borax additives on milling performance of aluminium alloys

The development of tribological properties of cutting fluids is important to ensure cutting efficiency in metal cutting processes. It is expected that the nano-cutting fluids obtained using nanoparticles as a tribological agent will provide high tribological performance. In this study, the suspension of borax - ethylene glycol and colloidal suspension of borax - ethylene glycol – nano-silver particles were used as cutting fluid for milling of AA7075 - T6 material and their tribological properties were investigated. The originality of this paper is the improvement of the lubrication function and heat transfer properties of cutting fluids by using borax and nano-silver additives. In the experimental part of the current study, borax was used for lubrication, and nano-silver particles were employed to improve the heat transfer properties of nano-cutting fluids. Both additives were synthesised using ethylene glycol which has high penetration ability. The prepared cutting fluids were applied to the cutting zone in pulverised form by minimum quantity of lubricant (MQL) technique due to the lower environmental and health impacts. In the experimental section, surface roughness values and cutting forces were measured and analysed according to the response surface method (RSM). Besides, chip morphologies were examined in microscale using SEM and EDX, and the effects of additives were discussed in detail. As a result, it was determined that the silver nano-particle additive reduced the surface roughness up to 13.88 %. However, any sufficient effect reducing the cutting forces was not observed.

Experimental study on the anti-wear and anti-corrosive properties of the water-soluble metalworking fluid dispersed with copper and aluminium oxide nanoparticles

Metal working fluids play a prominent role in the machining operation, to provide better lubrication and surface finish of the machined products. The deprived heat transfer and lubricating property of these conventional fluids causes severe problems to meet the demands of the industry. In recent years, nano-size solid particles have received considerable attention and widely used as additives to improve the thermal and lubricating properties of the cutting fluids. In the current study, nano-metalworking fluids were formulated by dispersing copper and aluminium oxide nanoparticles in the mineral oil based water soluble metal working fluid, in different volume fractions. The tribological characteristics of the synthesized nano-cutting fluids were assessed through the anti-wear and extreme-pressure (EP) tests carried out in Four-ball tester as per ASTM standards. The enrichment in the anti-corrosive properties of the nano-metal working fluids was investigated with the aid of standard iron-chip corrosion test. The cutting fluid containing copper nanoparticles and aluminium oxide nanoparticles shows, considerable reduction in the wear rate and coefficient of friction. The load carrying capacity was enhanced maximum by 5% for the fluid sample containing aluminium oxide nanoparticles rather than base fluid. The coefficient of friction was gently reduced by 15% for the aluminium oxide based cutting fluid sample. From the tribological test results it was observed that the aluminium oxide based nano-cutting fluid shows superior resistance towards wear rate and friction than the copper based cutting fluid. The modified nano-cutting fluids with nanoparticles show signs of a better resistance towards corrosion.

Influence of nano (h –BN) cutting fluid on machinability of Inconel 625

Inconel 625 has got wide applications across industries (aerospace, petrochemical etc.) in various machining operations. During machining, large amount of heat is generated due to the friction, lowering the tool life and adding to various wear mechanism. This is sorted by conventional cooling/lubrication, but, with its harmful effect on environment and human health, it’s imperative to pursue other cleaner, greener though efficient alternatives. In this regard, MQL assisted with h-BN nano fluid is an effective option. Hexagonal Boron Nitride (h-BN) having unique structure and composition displays advanced mechanical properties which enhances its versatility in applications. To investigate effectiveness of nano (h –BN) cutting fluid on machinability, first h-BN nanofluid was prepared and characterized for its mechanical properties for nanoparticle concentrations (0.05,0.1 % Vol.). Further, the machining performance and sustainability associated with turning of Inconel-625 under different lubricating conditions viz. dry, wet, MQL with conventional cutting fluid and MQL with (h-BN) nano cutting fluid (NCF) are investigated for machining characteristics. Results showed that MQL integrated with h-BN nano cutting fluid is an effective and sustainable option.

Measurement of machining forces and surface roughness in turning of AISI 304 steel using alumina-MWCNT hybrid nanoparticles enriched cutting fluid

Researchers so far have given more attention to the performance of mono type nanoparticle enriched cutting fluids in machining. In present investigation, a hybrid nano-cutting fluid has been developed by mixing alumina based cutting fluid with multi walled carbon nano tube (MWCNT) nanoparticles in different volumetric concentrations of 0.25, 0.75 and 1.25 vol%. The prepared hybrid and base (Alumina nanofluid) nanofluids were tested for their thermophysical properties. Furthermore, pin on disc test and contact angle measurement of all the nanofluid samples were performed to understand their tribological behaviour and spreadability, respectively. The results revealed that the increase of nanoparticle concentration in cutting fluid reduced the wear and the lowest wear was observed with hybrid nanofluid. Later their performances as a cutting fluid by using minimum quantity lubrication (MQL) technique has been evaluated during turning of AISI 304 steel in the terms of machining forces and surface roughness and regression models have been developed for machining forces and surface roughness. The results clearly establish that the performance of hybrid nanofluid is found to be significantly better compare to alumina nanoparticle mixed cutting fluid.

A comprehensive review on minimum quantity lubrication (MQL) in machining processes using nano-cutting fluids

The cutting fluid is significant in any metal cutting operation, for cooling the cutting tool and the surface of the workpiece, by lubricating the tool-workpiece interface and removing chips from the cutting zone. Recently, many researchers have been focusing on minimum quantity lubrication (MQL) among the numerous methods existing on the application of the coolant as it reduces the usage of coolant by spurting a mixture of compressed air and cutting fluid in an improved way instead of flood cooling. The MQL method has been demonstrated to be appropriate as it fulfills the necessities of ‘green’ machining. In the current study, firstly, various lubrication methods were introduced which are used in machining processes, and then, basic machining processes used in manufacturing industries such as grinding, milling, turning, and drilling have been discussed. The comprehensive review of various nanofluids (NFs) used as lubricants by different researchers for machining process is presented. Furthermore, some cases of utilizing NFs in machining operations have been reported briefly in a table. Based on the studies, it can be concluded that utilizing NFs as coolant and lubricant lead to lower tool temperature, tool wear, higher surface quality, and less environmental dangers. However, the high cost of nanoparticles, need for devices, clustering, and sediment are still challenges for the NF applications in metalworking operations. At last, the article identifies the opportunities for using NFs as lubricants in the future. It should be stated that this work offers a clear guideline for utilizing MQL and MQL-nanofluid approaches in machining processes. This guideline shows the physical, tribological, and heat transfer mechanisms associated with employing such cooling/lubrication approaches and their effects on different machining quality characteristics such as tool wear, surface integrity, and cutting forces.

Performance Evaluation of Vegetable Oil-Based Nano-Cutting Fluids in Environmentally Friendly Machining of Inconel-800 Alloy.

Recently, the application of nano-cutting fluids has gained much attention in the machining of nickel-based super alloys due their good lubricating/cooling properties including thermal conductivity, viscosity, and tribological characteristics. In this study, a set of turning experiments on new nickel-based alloy i.e., Inconel-800 alloy, was performed to explore the characteristics of different nano-cutting fluids (aluminum oxide (Al2O3), molybdenum disulfide (MoS2), and graphite) under minimum quantity lubrication (MQL) conditions. The performance of each nano-cutting fluid was deliberated in terms of machining characteristics such as surface roughness, cutting forces, and tool wear. Further, the data generated through experiments were statistically examined through Box Cox transformation, normal probability plots, and analysis of variance (ANOVA) tests. Then, an in-depth analysis of each process parameter was conducted through line plots and the results were compared with the existing literature. In the end, the composite desirability approach (CDA) was successfully implemented to determine the ideal machining parameters under different nano-cutting cooling conditions. The results demonstrate that the MoS2 and graphite-based nanofluids give promising results at high cutting speed values, but the overall performance of graphite-based nanofluids is better in terms of good lubrication and cooling properties. It is worth mentioning that the presence of small quantities of graphite in vegetable oil significantly improves the machining characteristics of Inconel-800 alloy as compared with the two other nanofluids.

Characterization of Vegetable Oil–Based Nanocutting Fluids

Abstract The quality of a product in manufacturing is appraised by dimensional accuracy and surface finish. Among many factors that influence these two aspects cutting fluids stimulate the quality of machined surfaces by improving machining performance. Before they are applied to machining, it is essential to assess the viability of the cutting fluids. This is done by evaluating their basic properties. This paper is an attempt to evaluate thermophysical properties of vegetable oil–based nanocutting fluids in view of ecofriendly machining with a focus on enhanced machining performance. In view of this aspect, carbon nanotubes (CnT) and nanoboric acid (nBA) nanoparticles with variation in percentage of nanoparticle inclusions (NPI) are dispersed in coconut oil. The nanocutting fluids thus formulated are tested for density, dynamic viscosity, and thermal conductivity. Specific heat and heat transfer coefficient are evaluated using empirical relations. It is observed that density, thermal conductivity, and dynamic viscosity increased with increase in NPI for CnT- and nBA-dispersed nanocutting fluids. Viscosity is found to decreasze with increase in temperature for both the types of nanocutting fluids. Specific heat increased slightly with increase in NPI from 0 % to 1.25 % for CnT-dispersed fluids, whereas a slight decrease was observed for nBA-dispersed fluids. Heat transfer coefficient has increased with increase in NPI for CnT-based fluids. Fluids dispersed with nBA exhibited an increase followed by a decrease in heat transfer coefficient with increase in NPI. On the whole, it is discerned that for CnT-dispersed coconut oil–based cutting fluids, basic properties are much better than those of their nBA counterparts.

A model for machining with nano-additives based minimum quantity lubrication

The high temperature generated when machining aerospace alloys namely, titanium and nickel alloys, accelerate the tool wear rate and affects the physical properties of the machined surface. Flood coolant is usually the effective traditional solution to dissipate the heat and reduce its negative impact on tool performance and surface integrity. The disposal of the coolant causes environmental concerns, and the generated fumes during machining also present health concerns. Minimum quantity lubricant is presented as an alternative coolant strategy to reduce the amount of used coolant and environmental concerns associated with flood coolant. Experimental investigations showed that MQL does not offer the same results obtained when using flood coolant during machining titanium and Inconel. However, the addition of nano-additives significantly improved the performance of MQL. In this work, an integrated model (i.e., finite element and finite volume) is developed to analyze various unique aspects of machining with nano-fluids under minimum quantity lubrication during cutting Inconel 718 and Ti-6Al-4V alloys. These aspects include the heat transfer characteristics of the resultant nano-cutting fluid, the interactions between the cutting tool and workpiece, the generated cutting temperature at different zones, and resulting residual stresses. The investigation was carried out through two main phases. A 2-D axisymmetric computational fluid dynamics (CFD) model is developed to simulate the thermal effect of resultant nano-mist and obtain the thermal characteristics of the nano-fluid. The obtained results are then used in the finite element model to simulate the machining process with nano-fluid. The average heat convection coefficients results provided from the proposed CFD model at standard room temperature demonstrated a good agreement with the theoretical values calculated throughout this work. Also, the simulated and experimental cutting forces showed better agreement in the case of cutting test performed without nano-additives (accuracy % ≈ 90%) than the cutting test performed with nano-additives (accuracy % ≈ 82.3%). This work presents a first attempt in the open literature to simulate the machining processes using MQL-nano-fluid.

Sustainable Cooling and Lubrication Strategies in Machining Processes: A Comparative Study

Applying an adequate cooling and lubrication technique during machining processes is an important issue which affects the machining system efficiency. Flood cooling offers an effective solution to reduce the effect of the high heat generated during cutting processes; however, it is not a sustainable strategy because of the health and environmental concerns associated with its utilization. Therefore, several cooling and lubrication strategies have been suggested and used as alternatives to the flood cooling. These strategies include; dry cutting, cryogenic approach, minimum quantity lubrication (MQL), nano-cutting fluids, and MQL-nano-fluids. In this work, a comparative study is presented to evaluate the sustainability effectiveness of these strategies. In order to evaluate the strategies effectiveness, five sustainability indicators are used; namely, energy consumption, personal safety and health, waste management, machining costs, and environmental impact. A weighted decision matrix is developed to assess the studied strategies in terms of the employed sustainable indicators.