Although nickel-based aerospace superalloys such as alloy 625 have superior properties including high-tensile and fatigue strength, corrosion resistance and good weldability, etc., its machinability ...is a difficult task which can be solved with alternative cooling/lubrication strategies. It is also important that these solution methods are sustainable. In order to facilitate the machinability of alloy 625 with sustainable techniques, we investigated the effect of minimum quantity lubrication (MQL), cryogenic cooling with liquid nitrogen (LN2) and hybrid-CryoMQL methods on tool wear behavior, cutting temperature, surface roughness/topography and chip morphology in a turning operation. The experiments were performed at three cutting speeds (50, 75 and 100 m/min), fixed cutting depth (0.5 mm) and feed rate (0.12 mm/rev). As a result, CryoMQL improved surface roughness (1.42 µm) by 24.82% compared to cryogenic cooling. The medium level of cutting speed (75 m/min) can be preferred for the lowest roughness value and lowest peak-to-valley height when turning of alloy 625. Further, tool wear is decreased by 50.67% and 79.60% by the use of MQL and CryoMQL compared with cryogenic machining. An interesting result that MQL is more effective than cryogenic machining in reducing cutting tool wear.
•PVD TiAlN and CVD TiCN/Al2O3 coated carbide inserts were used in the milling experiments.•Taguchi experimental design (L18) was used for optimizing the machining parameters.•It was found that the ...feed rate was the most significant factor on Ra.•It was found that the cutting speed was the most significant factor on Vb.•Taguchi method was very successful in optimization of the machining parameters.
In this paper, the Taguchi method and regression analysis have been applied to evaluate the machinability of Hadfield steel with PVD TiAlN- and CVD TiCN/Al2O3-coated carbide inserts under dry milling conditions. Several experiments were conducted using the L18 (2×3×3) full-factorial design with a mixed orthogonal array on a CNC vertical machining center. Analysis of variance (ANOVA) was used to determine the effects of the machining parameters on surface roughness and flank wear. The cutting tool, cutting speed and feed rate were selected as machining parameters. The analysis results revealed that the feed rate was the dominant factor affecting surface roughness and cutting speed was the dominant factor affecting flank wear. Linear and quadratic regression analyses were applied to predict the outcomes of the experiment. The predicted values and measured values were very close to each other. Confirmation test results showed that the Taguchi method was very successful in the optimization of machining parameters for minimum surface roughness and flank wear in the milling the Hadfield steel.
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.
Aluminum (Al) alloys are of particular importance to the aerospace industry owing to the combination of characteristics including strength, ductility, toughness, fatigue life and oxidation resistance ...as a light metal. This is the case of AA 2024 T3 Al alloy. In particular, machining of these alloys has similar importance for productivity and part quality. Recently, the use of nanofluids, which have various advantages in terms of both cooling ability and tribological aspects, has become popular for the efficient machining of such alloys. In this context, guiding data are needed that enable industry and researchers to machine these types of alloys with high efficiency. Taking these into account, in this study, AA 2024 T3 Al alloy was machined and various machinability indicators such as surface roughness, surface topography, maximum temperature and dominant tool wear mechanism under different cooling/lubrication strategies i.e., dry cutting, base fluid minimum quantity lubrication (MQL) and mineral oil based MoS2 nanofluid MQL (NFMQL) were investigated. As a results, significant improvements have been achieved in surface roughness, surface topography, and maximum temperature with help of NFMQL application. The intensive built-up edge (BUE) and built-up layer (BUL) formations are produced on the cutting tool when machining AA 2024 T3 Al alloy under dry cutting. On the other hand, BUE formation has been significantly eliminated thanks to NFMQL. Moreover, a less damaged cutting edge was obtained when machining Al alloy under NFMQL compared to both dry cutting and MQL environments.
This study investigated the effects of eco-friendly cutting conditions on machining performance in the milling of Inconel X-750 superalloy. To this purpose, a total of 14 different eco-friendly ...cutting conditions, including dry, base fluid and three different nanofluids at four different concentrations were tested. Surface roughness, cutting temperature, cutting force, tool wear and tool life were addressed as performance criteria. According to the test results, the use of base fluid increased the machining performance significantly compared to the dry cutting; however, the best results on all performance characteristics were obtained under nanofluid cutting conditions. The optimal concentration for the nanofluids was determined as 0.50 vol% and the hexagonal boron nitride (hBN) nanofluid was shown to be superior to the MoS2 and graphite nanofluids.
•Milling performance of Inconel X-750 under eco-friendly conditions was examined.•Dry, base fluid, hBN, graphite and MoS2 nanofluid cutting conditions were tested.•Performance criteria included roughness, force, temperature, and tool wear/life.•Nanofluid cutting conditions gave the best results for all performance criteria.•The 0.5 vol% hBN nanofluid provided significant improvement in machining performance.
Son yıllarda ekolojik soğutma/yağlama yöntemleri sürdürülebilir imalat için metal işleme operasyonlarında kullanılmaya başlanmıştır. Bu yöntemlerin başında ise birbirine göre üstün özelliklerin bir ...araya getirildiği hibrit soğutma/yağlama yöntemlerinin kullanıldığı çalışmalar ön plana çıkmaktadır. Bu çalışmada; AISI 2507 dubleks paslanmaz çeliğinin Minimum Miktarda Yağlama (MMY), kriyojenik soğutma (Kry) ve hibrit (Kry+MMY) soğutma/yağlama koşulları altında tornalanmasında, yüzey kalitesi incelenmiştir. İşlenen yüzeylerin kalitesinin belirlenmesinde yüzey pürüzlülük (Ra), iki boyutlu yüzey görüntüleri ve üç boyutlu yüzey topografyaları kullanılmıştır. Deneyler üç farklı soğutma/yağlama koşulunda (MMY, Kry ve Kry+MMY), kesme hızında (80, 120 ve 160 m/dak) ve ilerlemede (0,16-0,20 ve 0,24 mm/dev) gerçekleştirilmiştir. Deney tasarımında ve optimum koşulların belirlenmesinde Taguchi L27 tasarımı kullanılmıştır. Deneysel sonuçlara etki eden faktörler ve faktörlerin etki oranlarını belirlemek için varyans analizi (ANOVA) kullanılmıştır. Deney sonuçlarına göre yüzey kalitesi için optimum koşullar, Kry+MMY hibrit soğutma/yağlama koşulu, 160 m/dak kesme hızı ve 0,16 mm/dev ilerleme olarak belirlenmiştir. En iyi Ra değeri (1,151 µm) A3, B3, C1 koşulunda, en kötü Ra değeri ise (-2,861 µm) A2, B1, C3 koşulunda elde edilmiştir.
In recent years, ecological cooling/lubrication methods were used in metal processing operations for sustainable manufacturing. The hybrid cooling/lubrication method, which combine superior cooling/lubrication methods with each other, were came to the fore.In this study; surface quality was investigated when turning AISI 2507 duplex stainless steel under Minimum Quantity Lubrication (MQL), cryogenic cooling (Cry) and hybrid (Cry+MQL) cooling/lubrication conditions. Surface roughness (Ra), 2D surface images and 3D surface topography were used to investigate the quality of the machined surfaces. The experiments were carried out in three different cooling/lubrication conditions (MQL, Cry and Cry+MQL), cutting speed (80, 120 and 160 m/min) and feed rate (0.16, 0.20 and 0.24 mm/rev).Taguchi L27 design was used in experimental design and determination of optimum conditions. Analysis of variance (ANOVA) was used to determine the factors affecting the experimental results and the effect rates of the factors. According to the experimental results, optimum conditions for surface quality were determined as Cry+MQL cooling/lubrication condition, 160 m/min cutting speed and 0.16 mm/rev feed rate. The best Ra value (1,151 µm) was obtained under A3, B3, C1 condition and the worst Ra value (-2,861 µm) was obtained under A2, B1, C3 condition.
Friction and high temperatures greatly affect machining efficiency when machining superalloy materials. Nanoparticles with high thermal conductivity and lubricity are preferred for increase lubricant ...performance. Nanofluids prepared with nanoparticles not only reduce environmental concerns but also positively affect the machining efficiency in the sustainable manufacturing process. However, some nanoparticles added in mono form stand out with their thermal conductivity and some nanoparticles with their lubricating performance. For this reason, the lubrication performance of hybrid nanofluids prepared with nanoparticles with different superior properties is a matter of interest. In this study, the machining performance of Inconel X-750 superalloy was investigated by using hexagonal boron nitride (hBN), graphite (Grpt), and MoS2 nanoparticles with different shapes and properties. For this purpose, the milling experiments were performed under three different hybrid nanofluid (hBN/Grpt, hBN/MoS2, and Grpt/MoS2) conditions, at three different cutting speeds (30, 45, and 60 m/min), and three different feed rates (0.05, 0.10, and 0.15 mm/rev). Cutting force, cutting temperature, surface roughness/topography, tool wear, and tool life were selected as machining performance criteria. According to the results obtained from the experiments, it was understood that the hBN/Grpt hybrid nanofluid outperformed hBN/MoS2 and Grpt/MoS2 conditions in all performance criteria. hBN/Grpt hybrid nanofluid achieved 36.17% and 6.08% improvement in tool life compared to Grpt/MoS2 and hBN/MoS2 nanofluids, respectively.
Nickel-based Inconel 625 is employed in critical applications because of its excellent properties. But the machinability of this material is very poor. In recent years, the use of minimum quantity ...lubrication has gained prominence to improve machining performance without increasing the oil. However, pure-MQL may be insufficient for machining of difficult-to-machine materials. This paper focused on the development of nano-MQL by adding hBN nanoparticles compared to pure-MQL and dry machining in turning of Inconel 625. Tool life, surface roughness, tool wear and tool-chip interface temperature were analyzed. Wear mechanisms were evaluated by SEM photographs and EDX analysis. The results showed that; 0.5 vol% hBN nanofluid has produced promising results for low tool wear and roughness and high tool life.
•Study of tool life, tool wear patterns, surface roughness and temperature.•Nanofluid-MQL with Hexagonal Boron Nitride Nanoparticles for sustainable machining.•Examining the tool wear mechanisms with SEM and EDX analysis.•Choosing the best operating parameter with single and multi-objective optimization.
Waspaloy gibi işlenebilirliği zor malzemelerin işleme verimliliğini artırmak için, kesme sıvısı kullanımı büyük
önem taşımaktadır. Ancak, aşırı kesme sıvısı kullanımı çevre, çalışan sağlığı ve üretim ...maliyeti gibi konularda
imalatçıları endişelendirmektedir. Bu endişeleri minimuma indirmek için kullanılan alternatif yöntemlerden
birisi de Minimum Miktarda Yağlama (MMY) sistemidir. Bununla beraber, kesme sıvısı miktarının azaltılması
için çalışmalar artarak devam etmektedir. Bu çalışmada, MMY sisteminde kullanılan kesme sıvısının içerisine
nanopartikül katkı maddesi eklenerek kullanılan kesme sıvısı miktarını daha da azaltmak amaçlanmıştır. Bu
amaç doğrultusunda, Waspaloy süper alaşımı; kuru, MMY ve NanoMMY (hacimce %1 Al2O3) şartları altında
işlenmiş ve soğutma/yağlama yöntemleri arasındaki farklar ortaya konulmuştur. Frezeleme deneyleri esnasında
çıktı olarak takım aşınması seçilmiştir. Kesme parametresi olarak ise üç farklı kesme hızı (20, 40, 60 m/dak) ve
üç farklı ilerleme hızı (0,05-0,10 ve 0,15 mm/dev) seçilmiştir. Deney sonuçlarının analizine göre, optimum
aşınma değeri 20 m/dak kesme hızı, 0,05 mm/dev ilerleme ve NanoMMY şartları altında gerçekleşmiştir.
The use of cutting fluids is of great importance in order to increase the machinability efficiency of difficult-tocut materials such as Waspaloy. However, the use of extreme cutting fluid is concerned by manufacturers in such
issues as the environment, human health and production cost. One of the alternative methods to minimize these
concern is the Minimum Quantity Lubrication (MQL) system. Moreover, researches are continued to reduce the
amount of cutting fluids. In this study, it was intended to further reduce the amount of cutting fluid so
nanoparticle was added to the contents of the cutting fluid in the MQL system. For this purpose, Waspaloy
milling experiment were carried out under dry, MQL and NanoMQL (1 vol% Al2O3) conditions and the differences between cooling/lubrication methods have been revealed. Tool wear was selected as output
parameter during milling experiments. Three different cutting speeds (20, 40, 60 m/min) and three different feed
rates (0.05, 0.10 and 0.15 mm/rev) were selected as cutting parameters. According to the analysis of the
experiment results, the optimum wear value was 20 m/min cutting speed, 0.05 mm/rev feed rate and NanoMMY
cutting conditions.
Nickel alloy X-750 which is difficult-to-machine material, is employed in many critical fields owing to its superior mechanical and thermal properties. However, these superior features lead to some ...difficulties in its machinability especially when using carbide tool materials. Hence, ceramic cutting tools (CCTs) having excellent hardness, heat and abrasion resistance, and poor chemical proximity to workpiece material are a perfect choice in machining operations of such materials. Considering this, the current study focused on the influence of various cutting environment, i.e., dry, base fluid-MQL without any mixed nanoparticles (BF-MQL) and hBN dispersed nanofluid-MQL (NF-MQL) on surface roughness, 2D-surface topography, maximum cutting temperature, cutting force, micro-hardness, flank wear and its mechanism when milling of alloy X-750 with Sialon ceramic tools. As a result, surface roughness was reduced by about 39% and 47.2% with BF-MQL (0 vol% additive) and hBN mixed NF-MQL, respectively compared to dry machining environment. Also the noticeable improvement with NF-MQL environment in 2D-surface topography of workpice, cutting temperature and cutting force has been achieved, the dry machining offered less tool wear for CCT than both BF-MQL and NF-MQL.
•Dry, BF-MQL and hBN mixed nanofluid-MQL were used in experiments.•Nickel alloy X-750 was milled with SiAlON tool under different machining modes.•Wear performance of SiAlON ceramic tool was investigated.•Microhardness, surface roughness/topography, force and temperature were studied.•NF-MQL exhibited good performance in surface condition, force and temperature.
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