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Analysis of surface roughness and energy consumption in turning of C17500 copper alloy under different machining environments and modellings with response surface method
(Sage Publications Ltd, 2023) Cakiroglu, Ramazan; Gunay, Mustafa
The difficulties in machinability due to the developments in the technical properties of engineering materials increase the importance of machinability indicators such as surface quality, power or energy consumption and tool life in terms of sustainable machining. In this context, the machinability of a copper-beryllium alloy (C17500), which is used in a wide range of industries and also characterized as a hybrid material, was investigated in vortex tube cooling and dry cutting environments. First, turning experiments were performed with a coated carbide tool and varying cutting speed, feed rate and depth of cut. In the experiments, the total energy consumed during turning and the roughness of the machined surfaces were measured, and analysed experimentally and statistically. In the second stage, mathematical models were developed for the total energy consumption and average surface roughness for both cutting environments with the response surface method. As a result, the chip formation process in the turning of the Cu alloy under vortex tube cooling negatively affected the cutting power and positively contributed to the surface quality. Due to the fact that vortex tube cooling creates a cooling effect rather than lubrication, built-up layer/built-up edge (BUL/BUE) formation on the tool cutting edges caused the change in the tool geometry and thus the chip removal process became more difficult and increased the energy consumption. On the other hand, in the vortex tube cooling application, the surface roughness decreased by an average of 31.4% compared to dry cutting. Furthermore, the predictive mathematical models developed for the total energy consumption and the mean surface roughness can be used with high reliability.
Analytical Modeling Methods in Machining: A State of the Art on Application, Recent Challenges, and Future Trends
(Springer Heidelberg, 2024) Korkmaz, Mehmet Erdi; Gupta, Munish Kumar; Sarikaya, Murat; Gunay, Mustafa; Boy, Mehmet; Yasar, Nafiz; Demirsoz, Recep
Information technology applications are crucial to the proper utilization of manufacturing equipment in the new industrial age, i.e., Industry 4.0. There are certain fundamental conditions that users must meet to adapt the manufacturing processes to Industry 4.0. For this, as in the past, there is a major need for modeling and simulation tools in this industrial age. In the creation of industry-driven predictive models for machining processes, substantial progress has recently been made. This paper includes a comprehensive review of predictive performance models for machining (particularly analytical models), as well as a list of existing models' strengths and drawbacks. It contains a review of available modeling tools, as well as their usability and/or limits in the monitoring of industrial machining operations. The goal of process models is to forecast principal variables such as stress, strain, force, and temperature. These factors, however, should be connected to performance outcomes, i.e., product quality and manufacturing efficiency, to be valuable to the industry (dimensional accuracy, surface quality, surface integrity, tool life, energy consumption, etc.). Industry adoption of cutting models depends on a model's ability to make this connection and predict the performance of process outputs. Therefore, this review article organizes and summarizes a variety of critical research themes connected to well-established analytical models for machining processes.
Application of grey relational analysis based on Taguchi method for optimizing machining parameters in hard turning of high chrome cast iron
(Springer, 2018) Kalyon, Ali; Gunay, Mustafa; Ozyurek, Dursun
High chrome white cast iron is particularly preferred in the production of machine parts requiring high wear resistance. Although the amount of chrome in these materials provides high wear and corrosion resistances, it makes their machinability difficult. This study presents an application of the grey relational analysis based on the Taguchi method in order to optimize chrome ratio, cutting speed, feed rate, and cutting depth for the resultant cutting force (F (R)) and surface roughness (R (a)) when hard turning high chrome cast iron with a cubic boron nitride (CBN) insert. The effect levels of machining parameters on F (R) and R (a) were examined by an analysis of variance (ANOVA). A grey relational grade (GRG) was calculated to simultaneously minimize F (R) and R (a). The ANOVA results based on GRG indicated that the feed rate, followed by the cutting depth, was the main parameter and contributed to responses. Optimal levels of parameters were found when the chrome ratio, cutting speed, feed rate, and cutting depth were 12%, 100 m/min, 0.05 mm/r, and 0.1 mm, respectively, based on the multiresponse optimization results obtained by considering the maximum signal to noise (S/N) ratio of GRG. Confirmation results were verified by calculating the confidence level within the interval width.
Application of Taguchi method for determining optimum surface roughness in turning of high-alloy white cast iron
(Elsevier Sci Ltd, 2013) Gunay, Mustafa; Yucel, Emre
This paper focused on optimizing the cutting conditions for the average surface roughness (R-a) obtained in machining of high-alloy white cast iron (Ni-Hard) at two different hardness levels (50 HRC and 62 HRC). Machining experiments were performed at the CNC lathe using ceramic and cubic boron nitride (CBN) cutting tools on Ni-Hard materials. Cutting speed, feed rate and depth of cut were chosen as the cutting parameters. Taguchi L-18 orthogonal array was used to design of experiment. Optimal cutting conditions was determined using the signal-to-noise (S/N) ratio which was calculated for R-a according to the the-smaller-the-better approach. The effects of the cutting parameters and tool materials on surface roughness were evaluated by the analysis of variance. The statistical analysis indicated that the parameters that have the biggest effect on R-a for Ni-Hard materials with 50 HRC and 62 HRC are the cutting speed and feed rate, respectively. Additionally, the optimum cutting conditions for the materials with 50 HRC and 62 HRC was found at different levels. (C) 2012 Elsevier Ltd. All rights reserved.
APPLICATION OF THE TAGUCHI METHOD TO OPTIMIZE THE CUTTING CONDITIONS IN HARD TURNING OF A RING BORE
(Inst Za Kovinske Materiale I In Tehnologie, 2015) Boy, Mehmet; Ciftci, Ibrahim; Gunay, Mustafa; Ozhan, Feridun
This paper is focused on optimizing the cutting conditions for the surface roughness, inner-diameter error and roundness obtained in hard turning of an inner ring bore. The hard-turning experiments were conducted on hardened and tempered AISI 52100 bearing rings using the L9 orthogonal array on a CNC lathe. The cutting speed, feed rate and number of the machined part were selected as control factors. The optimum cutting conditions were determined using the signal-to-noise (SIN) ratio. S/N ratios were calculated using the lower-the-better approach. An analysis of variance (ANOVA) was also employed to determine the level of the effect of the control factors for the surface roughness, inner-diameter error and roundness. The statistical analysis showed that the feed rate was the most significant factor for the surface roughness while the cutting speed was the most significant factor for the roundness and inner-diameter error. Finally, the optimum cutting conditions were further confirmed with confirmation tests.
Biomedical Applications with Multiscale Structures Produced by Additive Manufacturing
(World Scientific Publ Co Pte Ltd, 2024) Gunay, Mustafa; Meral, Tolga
In biomedical applications, various additive manufacturing (AM) techniques such as fused deposition modeling (FDM), inkjet, stereolithography (STL), direct powder extrusion (DPE), and selective laser sintering (SLS), as well as other digitally controlled 3D printing (3DP) techniques, are used. Advances in AM methods have led to the development of tissues, microdevices, artificial organs, personalized prostheses and orthoses, dental and various bone implants, biopharmaceutical applications and drug delivery system (DDS), and patient-specific surgical models, etc. that require multiscale structures, materials and functions. It enables the three-dimensional (3D) design and manufacturing of biomedical products with complex geometries. Additionally, it enables the modeling and 3DP using the biomimetic approach for applications that require lightweight and durable structures as well as biocompatibility. The purpose of this study is to review macro-to-nano multiscale AM technologies, design and modeling status, materials, and applications used for biomedical applications. Additionally, recommendations are given on what needs to be done to overcome the current limitations and challenges of micro/-nano printing in current AM technologies.
Comprehensive analysis of material removal rate, tool wear and surface roughness in electrical discharge turning of L2 tool steel
(Elsevier, 2020) Cakiroglu, Ramazan; Gunay, Mustafa
Electrical discharge turning (EDT) is used in the production of micro and macro cylindrical components with complex geometry, as well as ejector pins in injection molds, components of micro air turbines and pumps, micro tools or microstamping dies. On the other hand, optimization of machining parameters is crucial for machining efficiency and surface integrity of a part produced directly by EDT. Therefore, the machinability of AISI L2 steel with die sinking EDT was comprehensively investigated by considering material removal rate (MRR), surface roughness (Ra) and tool wear rate (TWR). In addition, machining parameters named as discharge current, pulse on time and pulse off time were optimized by Taguchi-based grey relational analysis method. Considering the measurement results and the observations of surface morphology, the MRR, TWR and Ra increased with increasing the discharge current. However, it was detected that MRR and Ra increased while TWR decreased as the pulse on time was increased. The increase in noncutting time due to the pulse off time increment led to forming of shallow craters and thus increased surface quality. The best machining parameters for die-sinking EDT of the tool steel were determined as discharge current of 3A, pulse on time of 8 mu s and pulse off time of 6 mu s. A 25.04% percentage of improvement of was achieved with the multiresponse optimization method during die-sinking EDT. (C) 2020 The Author(s). Published by Elsevier B.V.
Confirmation of Johnson-Cook Model Parameters for Nimonic 80A alloy by Finite Element Method
(Gazi Univ, 2020) Korkmaz, Mehmet Erdi; Gunay, Mustafa
Nimonic 80A superalloy is frequently used due to its high creep resistance, oxidation resistance and high resistance to high temperature corrosion. On the other hand, due to compatibility of simulation of plastic deformation processes, Johnson-Cook model is chosen among the materials models such as Zerille Armstrong, Bordner Partom, Steinberg-Guinan etc. In this study, primarily, quasi-static compression tests were performed for 10-3, 10-2 and 10-1 s-1 strain rates at room temperature. Secondly, dynamic compression tests were secondly conducted at high strain rates ranging from 370 to 954 s-1 using the Split Hopkinson Pressure Bar (SHPB) apparatus. Then, the compression tests were conducted at a temperature level from 24 similar to 200 degrees C at the reference strain rate. Johnson-Cook model parameters of Nimonic 80A were determined by analyzing the data obtained from the tests. Lastly, the compression simulations with fmite element method (FEM) were performed in ANSYS Workbench to confirm the accuracy of the parameters. In the light of the results, it was determined that there is an average of %3.23 deviation between the experimental and the simulation values. The result showed that accuracy of the Johnson-Cook parameters for Nimonic 80A superalloy was verified with FEM.
Cutting forces and temperature measurements in cryogenic assisted turning of AA2024-T351 alloy: An experimentally validated simulation approach
(Elsevier Sci Ltd, 2022) Gupta, Munish Kumar; Korkmaz, Mehmet Erdi; Sarikaya, Murat; Krolczyk, Grzegorz M.; Gunay, Mustafa; Wojciechowski, Szymon
Aluminium alloys are widely used in modern engineering applications such as automobile, aerospace etc because of its characteristics. The machining of aluminium alloys are also considered as difficult because of its sticky and soft nature, low thermal conductivity, strain hardening effect etc. The cooling conditions employed at cutting zone improved the machining performance but the resources, material consumption, skilled labor etc. are also required for performing the machining experiments. Therefore, the simulation of process parameters with the help of Finite Element Modelling (FEM) during machining is highly researched topic these days. In this work, a new practice from measurement science i.e., FEM simulation was performed with AdvantEdge software and the prediction models were developed for evaluating the cutting forces and cutting temperature while machining AA2024-T351 alloy under dry, liquid nitrogen (LN2) and carbon dioxide (CO2) conditions. Initially, the 3D turning model was developed and the results were compared with experimental findings. The results obtained from simulation model are very close with experimental results with minimum standard value of 0.67 (5.7%) for cutting forces and 4.58 (6.16%) for cutting temperature. Thus, it is worthy to mention that the 3D FE model is efficient and effective to predict and measurement results with minimum error.
Dry Sliding Wear Behaviours of Valve Seat Inserts Produced from High Chromium White Iron
(Walter De Gruyter Gmbh, 2015) Kalyon, Ali; Ozyurek, Dursun; Gunay, Mustafa; Aztekin, Hasan
In this present study, wear behaviours of high chromium white iron valve seat inserts and tappets used in the automotive sector were investigated. Wear behaviours of three different rates of high chromium white cast irons (containing 10, 12 and 14% chromium) were examined under heavy service conditions. For that purpose, the produced valve seat inserts were characterized through Scanning Electron Microscopy (SEM), Energy Dispersive Spectroscopy (EDS), X-ray diffraction (XRD) and hardness measurements. They were tested at a sliding speed of 1 ms(-1), under 120 N load and for six different sliding distances (500, 1000, 1500, 2000, 2500, 3000 m) by using a standard wear apparatus (pin-on-disk type). The result showed that as the amount of Cr increased in the alloys, their hardness decreased. The decrease in the hardness were considered to be as the result of transformation of M7C3 carbides into M23C6 carbides in the structure. This decrease in hardness with increasing chromium content also increased the weight loss. Thus, it was determined that the white iron with 14% Cr (which had a greater amount of M23C6 carbides) was subjected to the highest wear.
The effect of drilling parameters for surface roughness in drilling of AA7075 alloy
(E D P Sciences, 2017) Yasar, Nafiz; Boy, Mehmet; Gunay, Mustafa
AA7075 aluminum alloy has been very popular significantly interest in the production of structural components in automotive and aviation applications due to its high strength, low density, good plasticity and better machinability comparable to many metals. Particularly, final products must have uniformly high quality to ensure essential safety standards in the aircraft industry. The optimization of hole quality which can variable according to tool geometry and drilling parameters is important in spite of high machinability rate of AA7075 alloy. In this study, the effects of drilling parameters on average surface roughness (Ra) has been investigated in drilling of AA7075 with tungsten carbide drills. Machining experiments were performed with three different drill point angles and three different levels of cutting parameters (feed rate, cutting speed). The effects of drilling parameters on thrust force has been determined with ANOVA in %95 confidence level. Feed rate was determined as the most important factor on Ra according to ANOVA results. Moreover, it was shown that increasing feed rate leads to increase of Ra while increasing drill point angle leads to decrease of Ra. The optimum surface roughness was obtained with point angle of 130 degrees, cutting speed of 40 m/min and feed rate of 0.1 mm/rev, thereby the validity of optimization was confirmed with Taguchi method.
Effect on Formations of Built-up Edge and Built-up Layer, Surface Roughness of Cutting Speed and Rake Angle in the Machining of Aluminum Alloys
(Gazi Univ, 2015) Sekmen, Mustafa; Gunay, Mustafa; Seker, Ulvi
In this study, the effects on surface roughness of cutting parameters (tool rake angle and cutting speed) were investigated in the machining of AA 2011 and AA 7075 aluminum alloys. The interactions between the cutting parameters and Build-up edge (BUE), Built-up layer (BUL) formed on tool rake face were also evaluated the same machining processes. In the machining tests, the testing apparatus which allowing chip removal by giving rake angle in both positive and negative side to the cutting tool was used. The average surface roughness (Ra) values for both alloys were considerably high in especially small values of rake angle (0 degrees and -5 degrees) for AA 7075 alloy, while Ra values for both alloys have been low in larger values of rake angle (15 degrees ve 20 degrees). The effect of the formations BUE and BUL of the rake angle and the alloy content were evaluated by examining uncoated carbide cutting tools used in cutting experiments with metallographic methods (SEM and EDS analysis). Consequently, the formation of BUE and BUL for AA 7075 alloy has been greater than that of AA 2011 alloy.
Effects of Severe Plastic Deformation on the Mechanical Properties of Welded ST37-2 Steel
(Eos Assoc, 2020) Sahhal, Abubaker; Gunay, Mustafa
Cold treatment techniques are used to enhance the mechanical properties of metal alloys, whose most important characteristics are strength, roughness, and microstructure. The aim of this research is to test the effect of Conventional Shot Peening (CSP) and Severe Shot Peening (SSP) on the mechanical properties of ST37-2 steel. The results of the experiments showed enhancements in surface roughness and tensile strength. However, shot peening decreased the ductility of the metal and caused changes in its microstructure that are indicated in the XRF and XRD tests. Results' data are provided as an original contribution to the literature while they are compared with the existing data.
Estimation of Fatigue Life of Cold Work Tool Steel Machined by Electrical Discharge Turning
(Gazi Univ, 2021) Cakiroglu, Ramazan; Gunay, Mustafa
In this study, it was aimed to determine the effects of machining parameters on the surface integrity and fatigue life of the machined part in electrical discharge turning (EDT). Initially, a mechanism was designed and manufactured to ensure rotation of the workpiece. EDT experiments were carried out on AISI L2 tool steel using three different discharge currents, pulse on time, pulse off time and constant rotational speed. The experiments were carried out according to the L-9 orthogonal array, and Rz, Sm and hardness values were measured as processing performance outputs. Finally, the fatigue life of the machined parts was estimated by applying the root area model and the change of theoretical fatigue life according to the machining parameters was investigated. According to experimental results, an increase in Rz and Sm parameters was determined with increasing the discharge current and pulse on time. The lowest Rz and Sm values were obtained at 3 A discharge current, 3 mu s pulse on time and 5 mu s pulse off time. Based on Taguchi analysis, the optimum theoretical fatigue stress was calculated as 643.932 MPa with root area model for the machined workpiece in the A1Ton1Toff3 experiment sequence.
Evaluation of the Mechanical Properties and Drilling of Glass Bead/Fiber-Reinforced Polyamide 66 (PA66)-Based Hybrid Polymer Composites
(Mdpi, 2022) Demirsoz, Recep; Yasar, Nafiz; Korkmaz, Mehmet Erdi; Gunay, Mustafa; Giasin, Khaled; Pimenov, Danil Yurievich; Aamir, Muhammad
In this study, mechanical testing of glass bead (GB), glass fiber (GF), and hybrid (GB/GF) composites was carried out. Following that, drilling tests were undertaken on glass bead/fiber-reinforced hybrid Polyamide 66 (PA66) polymer composites. The purpose of this study is to determine the mechanical properties of the cutting elements and the effect of cutting parameters (spindle speed and feed rate) and reinforcement ratios on thrust force and surface roughness (Ra). The contribution of the cutting parameters to the investigated outcomes was determined using statistical analysis. Optical microscopy and scanning electron microscopy (SEM) was used to inspect the hole quality and damage mechanisms. The results revealed that the feed rate was the most contributing factor to thrust force (96.94%) and surface roughness (63.59%). Furthermore, in comparison to other hybrid composites, the lowest R-a value was obtained as 0.95 mu m in samples containing 30% GB, while the R-a value was 1.04 mu m in samples containing 10% GF + 20% GB. Polymer PA reinforced with 30% GF had the highest strength, modulus of elasticity, impact strength, and hardness.
An Evaluation on Machining Processes for Sustainable Manufacturing
(Gazi Univ, 2013) Gunay, Mustafa; Yucel, Emre
Sustainable manufacturing consists of environmental protection, profitability and societal benefit for all industrial areas. Manufacturing practices are investigated for optimize production efficiency while minimizing environmental impact and maintaining social equity. It can be achieved through changes in products, processes and systems related to the sustainability issues. In sustainable manufacturing process, the natural resources which are key elements of sustainability must be used prudently by academic, scientific, cultural and human organizations. In this context, sustainable machining can be defined as a process which has been performed of sustainable manufacturing by using alternative machining technologies such as cryogenic machining, high pressure jet assisted machining. Sustainable machining investigates the conflict and synergy between economical and environmental considerations as well as the effect of system boundaries in determining optimum machining conditions. This paper presents a general evaluation on the importance of sustainable machining technologies in obtaining sustainable manufacturing objectives.
EXPERIMENTAL AND STATISTICAL ANALYSIS ON MACHINABILITY OF NIMONIC80A SUPERALLOY WITH PVD COATED CARBIDE
(Yildiz Technical Univ, 2018) Korkmaz, Mehmet Erdi; Gunay, Mustafa
Nimonic80A is a new superalloy which is used in aerospace technology due to its resistance against high temperature and oxidation. This study addresses an investigation of machinability outputs on Nimonic80A superalloy, including cutting forces and surface roughness. Turning experiments on different cutting conditions with PVD coated carbide were carried out on CNC lathe to determine the cutting forces and surface roughness. Three different cutting parameters, namely cutting velocity, cutting depth and feed rate are used with three different levels. The effect levels of the cutting parameters are determined with analysis of variance (ANOVA) with 95% confidence level. Then, a regression model is applied to predict the results of cutting forces and surface roughness in the certain range of cutting conditions. The results show that the cutting depth has the highest significance on main cutting force (F-c) and feed force (F-f) while the feed rate has the highest significance on radial force (F-r) and surface roughness (R-a). The cutting velocity has much less effect onto cutting force when it improves surface roughness. Finally, the deviation between experimental and second order regression model results for F-c, F-r, F-f and R-a are calculated as 4.53%, 3.21%, 7% and 9.12%, respectively.
AN EXPERIMENTAL INVESTIGATION OF EFFECT OF CUTTING PARAMETERS ON CUTTING ZONE TEMPERATURE IN DRILLING
(Gazi Univ, Fac Engineering Architecture, 2013) Yagmur, Selcuk; Acir, Adem; Seker, Ulvi; Gunay, Mustafa
Drilling is one of the most important machining processes in manufacturing industry. Recently, the work dealing with the problems encountered during drilling and their solution has been increased. Modelling of thermal and mechanical loads developed during drilling has also been increased. In this study, the drillability of AISI 1050 steel widely used in industrial applications will be investigated under various drilling types (hole type) cutting parameters (60, 75, 90 and 108 m/min cutting speed and 0.15, 0.20 and 0.25 mm/rev feed) and cutting tool type (uncoated and TiN/TiAl/TiCN coated solid carbide). Cutting temperatures developed along the drill rake face when drilling with coated and uncoated drill bits will be measured with the help of K type thermocouples inserted in the cooling channels of the drills. When the results of the experiments are evaluated, cutting temperature decreased with increasing feed and coating application significantly reduced cutting temperatures in the cutting zone. Coating application has provided significant benefits in the all parameters.
Experimental investigation on novel drilling strategy of CFRP laminates using variable feed rate
(Springer Heidelberg, 2019) Yasar, Nafiz; Gunay, Mustafa
This study focused on the influences of drilling parameters on hole quality and thrust force in drilling of carbon fiber-reinforced polymer (CFRP) composite laminates via variable feed rate. Drilling experiments were carried out by using three different cutting speeds, feed rates and the qualities of tungsten carbide drill. Scanning electron microscopy and coordinate measurement machine were used for hole surface damage and diameter analyses, and also a portable instrument and 3D optical profilometer were utilized for surface roughness measurement. It was identified that thrust force (F-z), delamination factor (F-d) and average surface roughness (R-a) values attained in drilling processes by variable feed rate are lower than those of constant feed rate with average of 14%, 3% and 18%, respectively. Besides, the hole diameter (D) values obtained with variable feed rate in hole exit were higher than those of constant feed rate. Moreover, the higher F-z values were obtained with diamond-coated and TiAlN-coated drills than those of uncoated drill with 55% and 77%, respectively. The interactive influences of drilling parameters on machinability factors were evaluated via analysis of variance, and then, the most significant parameter was specified as the feed rate for F-d, just as the drill quality for F-z, R-a and D. According to the experimental and statistical results, we suggested that the novel drilling strategy is a significant alternative for the step hole and conventional drilling of CFRP laminates.
Experimental Measurement of Tool-Chip Interface Temperature With Pyrometer in Turning
(Gazi Univ, 2011) Duran, Abdullah; Turgut, Yakup; Gunay, Mustafa
In this study, tool-chip interface temperature occurred during machining of AISI 1040 steel with uncoated cemented carbide inserts were measured. Machining experiments were performed on a CNC lathe under dry conditions. In the experiments, five different cutting speeds (75-125-175-225-275 m/min), three different feed rate (0,1-0,2-0,3 mm/rev) and two different depth of cut (1-2 mm) were used. During cutting process, temperature values measured at the closest point to tool-chip interface were recorded to a personal computer using a pyrometer, fiber optic cables and other circuit elements. According to experimental results, it was determined that temperature generated on cutting zone increased with increases in depth of cut and feed rate. Additionally, tool-chip interface temperature increased with increasing cutting speed, but the tendency of increase in the temperature slightly decreased after cutting speed of 125 m/min.

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