Burr Width Research Articles

Study on improving surface integrity for additively manufactured Inconel 718 via high-speed micromilling

ABSTRACT The surface finish required for the application of products to aerospace and defense sectors cannot be produced by additive manufacturing (AM), and hence, a secondary finishing process is required post-additive manufacturing. Consequently, the current study analyses the ability of micromilling to enhance surface integrity for AM Inconel 718. Micromilling has been performed at three different levels of cutting conditions. The force induced during micromilling, surface finish, and top burr width for machined workpieces has been analyzed. A minimum value of 50 nm has been achieved for surface finish post-machining at a feed of 2 µm/flute and a speed of 50,000 rpm. An upmilling strategy has been found to be generating a lower top burr width compared to downmilling with a minimum value of 141 µm. A stability plot has also been constructed for the micromilling of AM Inconel 718 and compared with the stability lobe for wrought Inconel at different cutting speeds.

Sustainability assessment of machining Al 6061-T6 using Taguchi-grey relation integrated approach

Modern machining requires reduction in energy usage, surface roughness, and burr width to produce finished or near-finished parts. To ensure high surface quality in machining processes, it is crucial to minimize surface finish and minimize burr width, which are considered as significant parameters as specific cutting energy. The objective of this study was to identify the optimal machining parameters for milling in order to minimize surface roughness, burr width, and specific cutting energy. To achieve this, the research investigated the impact of feed per tooth, cutting speed, depth of cut, and number of inserts on the responses across three intervals using Taguchi L9 array. Observing the responses by varying these parameters, underlined the need for multi objective optimisation. Machining conditions of 0.14 mm/tooth fz, 350 m/min Vc and 2 mm ap using 1 cutting insert (exp no 9) was identified as the best machining run using grey relational analysis owing to its highest grey relational grade of 0.936. ANOVA examination identified cutting speed as the leading factor impacting the grey relational grade with 31.07 % contribution ratio, with the number of inserts, depth of cut, and feed per tooth also making notable contributions. Conclusively, machining parameters identified through response surface optimisation resulted in 21.69 % improvement in surface finish, 11.39 % reduction in specific energy consumption, and 6.2 % decrease in burr width on the down milling side albeit with an increase of 9 % in burr width on the up-milling side.

Micro-Milling of Additively Manufactured Al-Si-Mg Aluminum Alloys.

Additively manufactured aluminum alloy parts attract extensive applications in various felids. To study the machinability of additively manufactured aluminum alloys, micro-milling experiments were conducted on the additively manufactured AlSi7Mg and AlSi10Mg. By comparing the machinability of Al-Si-Mg aluminum alloys with different Si content, the results show that due to the higher hardness of the AlSi10Mg, the cutting forces are higher than the AlSi7Mg by about 11.8% on average. Due to the increased Si content in additively manufactured Al-Si-Mg aluminum alloys, the surface roughness of AlSi10Mg is 26.9% higher than AlSi7Mg on average. The burr morphology of additively manufactured aluminum alloys in micro-milling can be divided into fence shape and branch shape, which are, respectively, formed by the plastic lateral flow and unseparated chips. The up-milling edge exhibits a greater burr width than the down-milling edge. Due to the better plasticity of AlSi7Mg, the burr width of the down-milling edge is 28.1% larger, and the burr width of the up-milling edge is 10.1% larger than the AlSi10Mg. This research can provide a guideline for the post-machining of additively manufactured aluminum alloys.

Research on theoretical and experimental investigations of burr formation mechanism in micro-milling process of medical ploy-l-lactide

Medical grade poly-l-lactide (PLLA) has been widely applied for medical devices and consumables, e.g. biodegradable cardiovascular stents and surgical thread, due to its excellent biocompatibility. High-speed micro-milling technology shows great potential in high-precision and high-quality manufacturing of material PLLA, while it usually produces problems such as material burrs and defects. There is few research and analysis on the material removal mechanism and theory in the micro-milling process of polymers, and thus this paper aims to investigate the burr formation mechanism and processing quality in micro-milling process of medical PLLA. Firstly, a novel thermal-mechanical coupled theoretical model was proposed by considering the minimum cutting thickness and cutting-edge radius size effects, which can reveal the plastic flow law during micro-milling process of polymer material. This model was used to calculate the burr width at up and down milling sides of cutting area. Then material characterization and micro-milling experiments on two types of PLLA with different molecular weights were carried out to validate the established theoretical model, and further the micro-milling parameters were optimized to achieve the control of material burr formation and growth. As a result, a cardiovascular stent was fabricated by micro-milling with the optimized parameters (spindle speed of 25,000 rpm, feed rate of 100 mm/min and axial depth of cut of 5 μm), and the stents obtained significantly high surface quality. These results suggest that the proposed theoretical model has great advantages in the high-quality micro-milling of medical material PLLA. This work provides a potential stent manufacture technique in the development and clinical application of bioresorbable polymeric stents.

Quality enhancement of micro-milled channels with automated laser assistance

AbstractMicrochannels are utilised on material surfaces of a body, allowing coolant to pass through them and enabling heat dissipation by increased contact area. Fabrication of metal surface microchannels is primarily achieved by employing a micro-milling process, which has drawbacks such as excessive cutting forces, top burrs, tool wear, and lower tool life. Alternatively, it is also realised by using Laser micro milling, which has problems associated with lower quality of surface finish, un-desired taper, heat-affected zone, and spatters. The existing literature, after due review of the current state of the art, has brought out gaps needing attention. These gaps are limited capability to reduce surface roughness, unaddressed burr width, and irregular bottom surface morphology, which affect microchannel quality. These gaps motivate this research work to improve and sustain the microchannel quality. To achieve the goals, this research work performs the fabrication of microchannels by micro-milling with automated laser assistance being achieved in two ways (a) sequentially, (b) non-sequentially, termed as LASMM and LPCMM, which are novel for the scientific community. The effects of micro milling parameters, spindle speed and feed on the quality were analysed while machining commercially pure titanium (cp-Ti). Results show that laser assistance to micro-milling provides a lower generation of undesired forces and lesser top burrs compared to micro-milling alone. In sequential laser assistance, the channels have a mean down burr width ~ 58% lower and a maximum down burr width ~ 38% lower than the channels done non-sequentially. In the case of up-burr width, a mean value ~ 60% lower and a maximum value ~ 73% lower is achieved in channels done non-sequentially as compared to those done sequentially. In the case of surface roughness, channels done sequentially have a maximum Sa value of 1.508 µm, a maximum Sq value of 1.912 µm whereas non-sequentially, they show a maximum Sa value of 3.495 µm, maximum Sq value of 4.59 µm. Steady tool wear is observed sequentially, whereas in non-sequential, rapid tool wear occurs after 500 mm of cutting length.

Effect of cutting conditions on tool wear and wear mechanism in micro-milling of additively manufactured titanium alloy

This study investigated the effects of different cutting conditions, including dry, flooded, chilled air, and the minimum quantity lubrication (MQL), on cutting forces, burr width, tool wear, and surface roughness using constant cutting parameters. The results showed that the minimum cutting forces were obtained with MQL, while the cutting forces obtained with dry and chilled air were 97% and 80% higher, respectively. During dry cutting, the tool diameter decreased by 3.4%, whereas in MQL and flood cutting, the tool diameter reduction was 2.2%. The minimum corner and edge radius change were achieved in MQL-assisted cutting. At the beginning of the cutting process, the difference between the Sa values obtained for dry and flood cutting was more than 200%, while at the end of the cutting process, this difference was about 140%. It was observed that chilled air has a positive effect on surface roughness. There is an average difference of 21% in burr widths between up and down milling.

Evaluation of Machining Variables on Machinability of Nickel Alloy Inconel 718 Using Coated Carbide Tools

The current work was undertaken with the research aim of experimental examination of tool wear, surface roughness and burr formation during the micro-milling of Inconel 718 using different coated tools. Inconel 718 is one of the most widely used materials for purpose-oriented utilization owing to its preferred mechanical and physical properties, including high strength and corrosion resistance. On the opposite end, the machining of Inconel 718 poses certain machinability challenges, which significantly elevates tool wear and subsequently surface roughness. Cutting speed, feed rate and depth of cut were selected as variable machining inputs. With reference to tool wear, all input variables were found to be significant, with tool coating having the highest contribution ratio of 36.19%. In case of surface roughness, cutting speed and tool coating were identified as effective input parameters with contribution ratios of 51.24% and 34.27%, respectively. Similarly, depth of cut proved to be an influential factor for burr height formation (in both up-milling and down-milling), whereas feed rate had the highest contribution ratios for burr width formation during up-milling and down-milling, i.e., 39.28% and 36.26%, respectively. Consequently, contour plots for output responses were drawn between significant parameters to analyze machinability. One of the vital research outcomes was the identification of a tool coating parameter that is significant for all four analyzed aspects of burr formation. In addition, regression equations were formulated for machining responses. The best- and worst-case scenarios for individual input parameters, as identified from main effects plots, were validated during confirmatory experimentation. Moreover, effects of input variables on output response were characterized using close-up imagery, and dominant wear mechanisms were also identified. The utility of the research is underlined by the optimization of the sustainability and productivity of the manufacturing process.

Experimental Evaluation of Surface Roughness, Burr Formation, and Tool Wear during Micro-Milling of Titanium Grade 9 (Ti-3Al-2.5V) Using Statistical Evaluation Methods

Titanium grade 9 (Ti-3Al-2.5V) stands out as a preferred material in various industrial applications because of its suitable properties. Its applications span diverse sectors, including precision manufacturing, where it is utilized to produce honeycomb structures for advanced aeronautics, as well as for certain biomedical components. In parallel, micro-milling has gained widespread utilization across medical, aerospace, and electronic industries due to the increasing demand for miniature products in these domains. This current research study aims to explore the impact of various micro-milling process parameters—specifically, feed rate, cutting speed, and depth of cut—on the surface quality, burr formation, and tool flank wear of titanium grade 9. Research findings reveal that the feed rate plays a major role in influencing surface roughness (contribution ratio (CR): 62.96%) and burr formation (CR: 55.20%). Similarly, cutting speed and depth of cut significantly affect surface roughness, contributing 20.32% and 9.27%, respectively, but are insignificant factors for burr width. Tool flank wear is primarily influenced by cutting speed (CR: 54.02%), with feed rate contributing 33.18%. Additionally, the feed rate and cutting speed are significant factors in determining the length of the burr, with contribution ratios of 77.70% and 7.77%, respectively. Confirmatory tests conducted at optimum parameters selected from the main effects plot validated the experimental results.

Machining aerospace aluminium alloy with cryo-treated and untreated HSS cutting tools

ABSTRACT In this study, effects of drilling parameters and cryogenic treatment, which were applied to the cutting tool (M35 HSS drill bit), on the burr width, surface roughness (Ra), chip formation and tool wear were investigated in drilling of AA2024-T3 aluminium alloy under dry drilling conditions. In this context, the drilling parameters determined based on the Taguchi experimental design were employed, and also, the analysis of variance (ANOVA) and regression analysis were performed. The spindle speed (1500, 3000 and 4500 rev/min), feed rate (100, 150 and 200 mm/min) and cutting tool (cryo-treated and untreated M35 HSS tools) were selected as machining parameters. In terms of average burr width, the performance of the cryo-treated (DC&T) HSS drill bit was 28.91% (for the highest value) and 46.96% (for the lowest value) better than that of the untreated (UT) HSS drill bit. According to Ra values, the performance of DC&T HSS drill bit was 13.29% (for highest value) and 12.01% (for lowest value) better than that of UT HSS drill bit. The flank wear (VB) of UT HSS drill bit was found to be approximately four times greater than the flank wear of DC&T HSS drill bit.

Multi-Objective Optimization of Micro-Milling Titanium Alloy Ti-3Al-2.5V (Grade 9) Using Taguchi-Grey Relation Integrated Approach

This study aims to optimize the cutting parameters for the micro-milling of titanium grade 9 (Ti-3Al-2.5V). The research employs Grey Relational Analysis (GRA) and Response Surface Methodology (RSM) techniques to find the optimal combination of cutting parameters to simultaneously minimize surface roughness, burr width, burr length, and tool wear, which are selected process outcomes. The findings from Grey Relational Analysis (GRA) identify experiment number 6, with cutting conditions of f (µm/tooth) = 0.45, Vc (m/min) = 25, and ap (µm) = 60, as the most productive experiment. Analysis of variance (ANOVA) is conducted to assess the significance and influence of the process cutting parameters on different process outcomes. ANOVA reveals that the feed rate and cutting speed are the most influential input parameters, with a contribution ratio (CR) of 24.08% and 14.62%, respectively. Furthermore, ANOVA indicates that the interaction among the process parameters also significantly influences the process outcomes alongside the individual cutting parameters. The optimized combination of cutting parameters obtained through the RSM technique produces superior results in terms of reducing the process outcomes. Compared to the best run identified by Grey Relational Analysis, there is a remarkable 36.25% reduction in burr width and an 18.41% reduction in burr length, almost half of the reduction achieved in burr width. Additionally, there is a 16.11% and 14.60% reduction in surface roughness and tool wear, respectively.

Wear behavior of AlTiN coated WC tools in micromilling of Ti6Al4V alloy using vegetable oil-based nanofluids

The performance of AlTiN coated WC tool with pure vegetable oil-based MQL, vegetable oil with mono (CuO, MoS2), and hybrid (CuO + MoS2) nanofluid-based MQL in micro-milling of Ti6Al4V is investigated, and compared with the dry condition. Viscosity, wettability, and coefficient of friction (COF) of pure soybean oil and mono and hybrid nanofluids are characterized. CuO nanofluid-based MQL exhibited the best result in the shearing-dominant region by reducing tool wear in terms of % diameter reduction, equivalent burr width, and specific cutting force by 68.98%, 37.55%, and 51.40%, respectively, compared to dry conditions, due to the best wetting nature and rolling action. In the plowing-dominant region, the performance of nanofluid-based MQL was not satisfactory owing to the entrapment of the nanoparticles underneath the tool.

Comparative Analysis of Minimum Chip Thickness, Surface Quality and Burr Formation in Micro-Milling of Wrought and Selective Laser Melted Ti64.

Selective laser melting (SLM) is a three-dimensional (3D) printing process that can manufacture functional parts with complex geometries as an alternative to using traditional processes, such as machining wrought metal. If precision and a high surface finish are required, particularly for creating miniature channels or geometries smaller than 1 mm, the fabricated parts can be further machined. Therefore, micro milling plays a significant role in the production of such miniscule geometries. This experimental study compares the micro machinability of Ti-6Al-4V (Ti64) parts produced via SLM compared with wrought Ti64. The aim is to investigate the effect of micro milling parameters on the resulting cutting forces (Fx, Fy, and Fz), surface roughness (Ra and Rz), and burr width. In the study, a wide range of feed rates was considered to determine the minimum chip thickness. Additionally, the effects of the depth of cut and spindle speed were observed by taking into account four different parameters. The manufacturing method for the Ti64 alloy does not affect the minimum chip thickness (MCT) and the MCT for both the SLM and wrought is 1 μm/tooth. SLM parts exhibit acicular α martensitic grains, which result in higher hardness and tensile strength. This phenomenon prolongs the transition zone of micro-milling for the formation of minimum chip thickness. Additionally, the average cutting force values for SLM and wrought Ti64 fluctuated between 0.072 N and 1.96 N, depending on the micro milling parameters used. Finally, it is worth noting that micro-milled SLM workpieces exhibit lower areal surface roughness than wrought ones.

Modelling and experimental validation of burr control in micro milling of metals

Classical deformation theories are limited to predicting microscopic deformation when the machining parameters are comparable to the dimension of a single grain. Micro-cutting is one such process where the physical phenomenon is significantly influenced by the microstructure characteristics and initial state of stress. The micro-features such as burrs caused owing to these cutting processes, are undesired and affect the quality of the product. In this study, an analytical methodology is proposed, supported by FEM pre-processing, to determine the burr morphology during the micro-milling process for Ti-6Al-4V, Al-6061 and OFHC-Cu. At first, the flow stress is calculated with the help of strain gradient and dynamic recrystallization methods; contact pressure on the cutting edge and minimum chip thickness are introduced through an FE simulation, this assists to find out the axial and radial plastic strain which eventually yields the dimensions of individual burrs. Peening of the material surface prior to micro-milling provided 67 % less formation of top burr. The average burr width and height are measured and validated with predicted results. The grain structure and dynamic recrystallization of the micro-milled surface are revealed by electron backscatter diffraction. Further, the burr distribution from FE modelling is verified with an SEM image.

A comparative study on the machinability of β-type novel Ti29Nb13Ta4.6Zr (TNTZ) biomedical alloys under micro-milling operation

β-type Ti29Nb13Ta4.6Zr (TNTZ) alloy is a new-generation alloy that does not contain toxic/allergic elements. The alloys have low Young's modulus (⁓60 GPa) close to the cortical bone, providing excellent biocompatibility over familiar commercial CP Ti or Ti6Al4V ELI. Different macro/micro-machining methods can be used to obtain the final shape of Ti alloys and impact on the implant's bio ecosystem and performance. This study compared the micro-mill machining performance of the TNTZ alloys with commercial CP Ti and Ti6Al4V ELI. Machining experiments were performed under similar and different cutting speeds and constant feed rate conditions. In the study, cutting forces, surface roughness, burr size and tool wear were obtained. The results showed that the Fx cutting forces for TNTZ are about 3 and 2 times higher than for CP Ti and Ti6Al4V alloys, respectively. Depending on the increasing cutting distance, the surface roughness of CP Ti and Ti6Al4V materials followed a similar trend. However, the surface roughness values for TNTZ alloy are higher and decrease with increasing cutting distance. Burr widths for CP Ti and Ti6Al4V are similar, but the milling direction at which maximum burr occurs varies. In the TNTZ alloy, the burr width is about 3 times higher, and the burr occurred inside the slot, not at the edge of the machined slot. The predominant type of damage in milling Ti6Al4V and CP Ti materials is abrasive and adhesive. The dominant damage type in TNTZ alloy is chipping. Increasing the number of revolutions in TNTZ causes the cutting forces and burr width to increase.

Statistical Analysis of Machining Parameters on Burr Formation, Surface Roughness and Energy Consumption during Milling of Aluminium Alloy Al 6061-T6.

Due to the increasing demand for higher production rates in the manufacturing sector, there is a need to manufacture finished or near-finished parts. Burrs and surface roughness are the two most important indicators of the surface quality of any machined parts. In addition to this, there is a constant need to reduce energy consumption during the machining operation in order to reduce the carbon footprint. Milling is one of the most extensively used cutting processes in the manufacturing industry. This research was conducted to investigate the effect of machining parameters on surface roughness, burr width, and specific energy consumption. In the present research, the machining parameters were varied using the Taguchi L9 array design of experiments, and their influence on the response parameters, including specific cutting energy, surface finish, and burr width, was ascertained. The response trends of burr width, energy consumption, and surface roughness with respect to the input parameters were analyzed using the main effect plots. Analysis of variance indicated that the cutting speed has contribution ratios of 55% and 47.98% of the specific cutting energy and burr width on the down-milling side, respectively. On the other hand, the number of inserts was found to be the influential member, with contribution ratios of 68.74% and 35% of the surface roughness and burr width on the up-milling side. The validation of the current design of the experiments was carried out using confirmatory tests in the best and worst conditions of the output parameters.

Study of burr width and height using ANOVA in laser hybrid micro milling of titanium alloy (Ti6Al4V)

Ti6Al4V is regarded as the “workhorse” in aerospace industry for its wide applications at high temperatures. Unique attributes are high strength to density ratio and outstanding material properties at high thermal conditions. This present-day work involves the pre-slotting on Ti6Al4V surface with the help of fibre Laser, followed by the operation of micro-milling on respective Laser engraved slots. Localized melting due to Laser ablation leads to the decrease in the surface contact between milling tool and material surface. Micro-milling in return helps to remove the Heat affected zones (HAZ) created during Laser engraving process. ANOVA helps to point out the contributing factors for burr width and height on both milling sides. Main effect plots generated during process optimization, help to point out optimal combination of input parameters for minimized burr width and height. Higher frequency of Laser helps to generate consistent slots. Lower rotational speeds are responsible for high values of burr width and height. Whereas high rotational speed leads to efficient chip removal, resulting in decreased burr width and height.

Micro-milling of Ti-6Al-4 V with controlled burr formation

• A methodology is proposed to suppress the burr generation by tailoring compressive residual stress on the workpiece during the micro-milling process. • The burr formation is reduced by 63% by incorporating compressive surface residual stress of 589 MPa at the material surface. • The cutting marks at the machined side-wall are investigated and found to depend on the frictional behaviour between the tool and the workpiece. • Dynamic recrystallization is captured by EBSD on the micro-milled slot. • User-defined constitutive flow and friction models are proposed to capture the mechanism of the burr formation and morphology of the chip. Burr generation is expected to be a function of the state of stress and microstructure of the material before micro-milling. Burr formation may be hindered by cold working process such as peening, as peening leads to grain refinement and the induction of residual stress at the material surface. The novelty of the present work is the numerical modelling and experimental verification of control of burr formation in micro-milling of Ti-6Al-4 V by introducing compressive residual stress on the surface of the workpiece. The practical significance of the current study is that the compressive residual stress suppresses the burr generation by up to 63% in terms of burr width and height. The resultant cutting forces are found to be 13% higher for pre-stressed material, compared to the ones without pre-stress. As the cutting-edge radius and grain size of the material are of comparable magnitude in the case of micro-milling, a strain gradient-based dynamic recrystallization constitutive flow model is developed and incorporated into a finite element model in Abaqus. In addition, the cut marks at the machined wall of the material, are modelled with a proposed friction model and verified with experiments. The results of the FEM model are found to agree with the experimental finding by up to 12%.

Performance evaluation of DLC and NCD coatings in micro-milling of Al7075-T6 alloy

The main problem in machining of aluminum alloys is the adhesion of chips to the cutting tool. In micro milling, chip adhesion causes a decrease in surface quality and contributes to micro burr formation. There are several ways to minimize chip adhesion, one of which is to coat the tool with the appropriate material. Carbon-based coatings are coating materials that can minimize chip adhesion. In this study, the performances of Diamond-Like Carbon (DLC) and Nano-Crystalline Diamond (NCD) coating materials in the micro-milling process of Al7075-T6 alloy were investigated in all aspects. The tests are performed under dry cutting conditions using various cutting parameters. Experimental results show that DLC and NCD coated tools produce approximately 20 % and 40 % lower forces, respectively. For fz ≤ 0.5 μm/tooth, no decisive influence of the coating material on the cutting forces is observed. For fz ≤ 0.5 μm/tooth, surface roughness and burr width increase significantly in uncoated and NCD coated tools due to size effect. A strong size effect was observed at feed values less than approximately 36 % of the tool edge radius in terms of surface roughness and <18 % of the tool edge radius in terms of burr width.

Hybrid laser and micro milling methods for higher depth microchannel fabrication

The performance of microchannels is dependent on the geometry, dimensions and surface quality. The most widely used methods for manufacturing microchannels are laser micro-milling (LMM), conventional micro-milling (CMM), micro-forming, and chemical etching. The main challenges in manufacturing microchannels with LMM are non-uniform dimensions, tapering effect, and low aspect ratio. In addition to that, tool wear and burrs formation on the top surface of channels are common challenges in conventional micro milling (CMM) techniques. In the present study, Hybrid micro milling techniques have been proposed to manufacture the better quality of micro-channels. The proposed methods include the application of laser and conventional micro milling in two approaches; laser pre-channel micro milling (LPCMM) and laser assisted sequential micro milling (LASMM). In the LPCMM approach, a pre-channel was fabricated by LMM followed by CMM, whereas in LASMM, the material was removed layer by layer by LMM followed by CMM. The proposed methods were compared with CMM considering cutting forces, surface finish, top burrs, tool morphology and flank wear as responses. As compared to CMM, results revealed that the hybrid methodologies mean down burr width decreased by 75 % and 20 %; mean up burr width reduced by 81 % and 20 %; and cutting force decreased by 24 % and 60 % in LASMM and LPCMM, respectively. However, surface roughness (Sa) increased by 7.5 % and 32 % in LASMM and LPCMM, respectively, because of the thermal effect of the laser beam on the fabricated channels.

An experimental investigations on effects of cooling/lubrication conditions in micro milling of additively manufactured Inconel 718

The demand for additive manufacturing (AM) technology is recently increased in the aerospace, biomedical, and automobile sectors due to the capability of producing complex components with zero tolerance. However, the small or precise part manufactured by AM process needs post-processing such as machining, polishing, etc. because of the poor surface quality characteristics. Therefore, in this paper, the micro-milling was performed on additively manufactured Inconel-718 alloy under different sustainable cooling conditions. The tool wear, surface roughness, and burr generated during micro-milling experiments were investigated under the effect of air, minimum quantity lubrication (MQL), and flood cooling conditions. The results demonstrated that the MQL conditions provide the proper cooling and lubrication effect, and this results in improved tool life (which is almost 45% higher compared to dry conditions. MQL also improved the product quality in terms of surface roughness (almost 65% less surface roughness). Other machining characteristics, such as burr width and cutting forces, were also improved in MQL and flood environments. However, it was noticed that milling with a chilled air environment has not given any significant improvement in terms of machining characteristics.