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Analysis of Surface Roughness and Flank Wear Using the Taguchi Method in Milling of NiTi Shape Memory Alloy with Uncoated Tools
(Mdpi, 2020) Altas, Emre; Gokkaya, Hasan; Karatas, Meltem Altin; Ozkan, Dervis
The aim of this study was to optimize machining parameters to obtain the smallest average surface roughness (Ra) and flank wear (Vb) values as a result of the surface milling of a nickel-titanium (NiTi) shape memory alloy (SMA) with uncoated cutting tools with different nose radius (r(epsilon)) under dry cutting conditions. Tungsten carbide cutting tools with different r(epsilon) (0.4 mm and 0.8 mm) were used in milling operations. The milling process was performed as lateral/surface cutting at three different cutting speeds (V-c) (20, 35 and 50 m/min), feed rates (f(z)) (0.03, 0.07 and 0.14 mm/tooth) and a constant axial cutting depth (0.7 mm). The effects of machining parameters in milling experiments were investigated based on the Taguchi L18 (2(1) x 3(2)) orthogonal sequence, and the data obtained were analyzed using the Minitab 17 software. To determine the effects of processing parameters on Ra and Vb, analysis of variance (ANOVA) was used. The analysis results reveal that the dominant factor affecting the Ra is the cutting tool r(epsilon), while the main factor affecting Vb is the f(z). Since the predicted values and measured values are very close to each other, it can be said that optimization is correct according to the validation test results.
Comparison of microwave absorption properties between BaTiO3/Epoxy and NiFe2O4/Epoxy composites
(Wiley, 2018) Akinay, Yuksel; Hayat, Fatih; Kanbur, Yasin; Gokkaya, Hasan; Polat, Safa
Microwave absorption properties of Epoxy/Nickel Ferrite (NiFe2O4) and Epoxy/Barium Titanate (BaTiO3) composites were investigated and compared in the 1-14 GHz. Epoxy/filler particles (NiFe2O4 and BaTiO3) composites were prepared with 85/15 mixture ratios via Ultrasonic Probe Sonicator method in solution. The complex permittivity (e '-e '') and permeability (mu '-mu '') of the composites have been measured at different microwave frequencies in 1-14 GHz via vector network analyzer (Keysight N9926A). The reflection loss (R-L) of composites was calculated and evaluated from camplex permitivity and permeability. The obtained results show that both composites exhibit the large R-L and broadband within the frequency range from 1 to 14 GHz for different thickness. Epoxy/BaTiO3 showed a better microwave absorption at the range of 6-7.2 GHz for 7 and 6 mm, at the range of 7.4-9.1 GHz for 5 mm. However, the Epoxy/NiFe2O4 exhibits the largest R-L and the widest bandwidth than those obtained from Epoxy/BaTiO3 composite. POLYM. COMPOS., 39:E2143-E2148, 2018. (c) 2017 Society of Plastics Engineers
Development of Forming Temperature Curves for Warm Deep Drawing Process Under Non-isothermal Conditions
(Springer Heidelberg, 2015) Cetin, M. Huseyin; Ugur, Abdullah; Yigit, Osman; Gokkaya, Hasan; Arcaklioglu, Erol
Temperature is the main effective process parameter in the warm deep drawing (WDD) process to improve the formability of light-weight engineering materials, and this feature requires the accurate measurement and assessment of temperature for process stability. In this study, an evaluation of the WDD process was conducted according to the forming temperature curves (FTCs) characterized from work piece temperatures instead of tool temperatures, as usual. To achieve this goal, a special index material was developed to accurately obtain FTCs from the work piece material under closed and heated tool conditions. The differences of temperature on work piece material are required to define temperatures by curves. The characteristic behavior of these curves was investigated under non-isothermal WDD of AA 5754-O. In the experimentation stage, the process parameters, namely FTC, blank holder force and punch velocity, which assure successful deep drawability, were determined according to the failure-free cups by analyzing wrinkling and tearing conditions and minimum cup height parameters as output parameters. As the next step, optimum conditions were investigated by evaluating the cup volume and spring-back parameters. As a general conclusion, approximately 330A degrees C in the flange-die radius region and 100A degrees C in the cup wall-punch bottom region are the ideal optimum temperatures for the warm deep drawing process.
Effect of abrasive water jet turning process parameters on surface roughness and material removal rate of AISI 1050 steel
(Carl Hanser Verlag, 2015) Kartal, Fuat; Gokkaya, Hasan
The purpose of this study was to optimize and determine the most important abrasive water jet turning (AWJT) operational parameters, such as nozzle diameter (0.75 and 1.3 mm), nozzle feed rate (5, 25 and 45 min(-1)), stand- off distance (2, 10 and 18 mm), abrasive flow rate (50, 150 and 350 g x min(-1)), and spindle speed (500, 1500 and 2500 min(-1)), regarding machining efficiency parameters, namely, average surface roughness Ra (mu m) and material removal rate (mm(3) x min(-1)), using AISI 1050 steel workpieces machined by abrasive water jet turning. Taguchi L-18(2(1) x 3(4)) orthogonal experimental design was used for the experimental design. Adequacy of the predicted linear regression model equations was tested using the method of ANOVA. These model equations were used to optimize the operational parameters of the surface roughness and material removal rate. Machinability charts, indicating the optimum processes with respect to the surface roughness and material removal rate for AISI 1050 steel workpieces, were developed and presented in this study. As a result of experimental studies, it is seen that nozzle feed rate proved to have the most significant impact on surface roughness by 48.7 %. Abrasive flow rate proved to have the most significant impact on material removal rate by 84.6 %. Using a nozzle diameter of 0.75 mm, the average surface roughness was improved while material removal rate decreased.
THE EFFECT OF CORE CONFIGURATION ON THE COMPRESSIVE PERFORMANCE OF METALLIC SANDWICH PANELS
(Inst Za Kovinske Materiale I In Tehnologie, 2019) Zurnaci, Erman; Gokkaya, Hasan
The compressive performance of metallic sandwich panels signifies a key mechanical behaviour under compression loading. This paper describes the compressive performance of metallic corrugated core sandwich panels having different core configurations under quasi-static compression loads. Two different sandwich panel core configurations were studied: the corrugated monolithic core and the corrugated sliced core. The corrugated cores were fabricated using a sheet-metal bending technique with trapezoidal geometry and then bonded to surface plates. Aluminium 1050 1114 sheets were used as the core and surface materials. Sandwich panel samples were prepared and tested experimentally under a quasi-static compression load (compression rate of 2 mm/min). The force-displacement curves of the sandwich panels with different core configurations were obtained from the experimental tests. The compressive performance parameters included the maximum compression load, the average compression load, the energy absorption and the specific energy absorption. It was found that the core configuration played a key role in the compressive performance. Finally, when the compressive performance of these two different core configurations was compared, the corrugated sliced-core configurations exhibited better performance.
The Effect of Cutting Parameters on Tool Wear During the Milling of Carbon Fiber Reinforced Polymer (CFRP) Composites
(Kaunas Univ Tech, 2019) Ozkan, Dervis; Gok, Mustafa Sabri; Gokkaya, Hasan; Karaoglanli, Abdullah Cahit
Reduction of machining times and optimization of cutting parameters and conditions hold great importance in machining processes. Milling is among the most important machining processes used for machining of fiber-reinforced composite materials. The present research was carried out to investigate the effect of cutting parameters on tool wear during the milling of carbon fiber reinforced polymer (CFRP) materials which are widely used in aviation and aerospace industries. A multi-directional CFRP composite material with 6 mm width and 26 layers was used as the workpiece. The tests were performed under dry conditions on a CNC vertical processing center with 100, 200 and 300 m/min cutting speeds; 0.05 , 0.15 and 0.25 mm/tooth feedrates and at 1 mm constant cutting width. To understand the wear process, scanning electron microscopy (SEM) analyses of the worn surfaces were performed.
THE EFFECT OF PROCESS PARAMETERS ON MACHINING VOLUME AND DEPTH OF CUT IN TURNING OPERATION OF AISI 1040 STEEL WITH ABRASIVE WATER JET
(Pamukkale Univ, 2014) Kartal, Fuat; Gokkaya, Hasan
In this study the effect of processing parameters during turning of AISI 1040 steel with abrasive water jet on machining volume and depth of cut. In the study, in order to keep the experiment quantity low, former studies in literature were taken into consideration and therefore experiments were realized with processing parameters and experiences that are most suitable to pre-experiments. In experimental studies pump pressure (350 MPa), abrader dimensions (in garnet form and dimension 80 mesh) and nozzle diameter (1.2 mm) were kept constant. 1040 steel with dimensions of empty set 30 and 240 mm were processed at four different abrader flow rate (50, 150, 250 and 350 gr/min), nozzle distance (2, 5, 8 and 11 mm), nozzle feed rate (5, 15, 25 and 35 mm/min) and lathe chuck revolutions (25, 50, 75 and 100 rpm). According to the findings the most highly material removal rate of 5 mm / min nozzle feed rate 1387.25 mm(3) in the amount has been achieved. The maximum depths of cut 0.94 mm spindle speed of 100 rpm were obtained.
The effects of cryogenic-treated carbide tools on tool wear and surface roughness of turning of Hastelloy C22 based on Taguchi method
(Springer London Ltd, 2016) Akincioglu, Sitki; Gokkaya, Hasan; Uygur, Ilyas
In this study, Taguchi method has been applied to evaluate the effect of cryogenically treated tools in turning of Hastelloy C22 super alloy on surface roughness. The optimum parameters (cryogenic treatment, cutting speed, and feed rate) of turning were determined by using the Taguchi experimental design method. In Taguchi method, L9 orthogonal array has been used to determine the signal noise (S/N) ratio. Analysis of ANOVA was carried out to identify the significant factors affecting surface roughness. The statistical analysis indicated that feed rate, with a contribution percentage as high as 87.64 %, had the most dominant effect on machining performance, followed by the cryo-treated tools treatment and cutting speed, respectively. The confirmation tests indicated that it is possible to improve surface roughness significantly by using the Taguchi method. Surface roughness was improved by 28.3 and 72.3 % by shallow (CT1) cryogenic treatment and deep cryogenic treatment (CT2) applied on cementite carbide tools (UT). It found that wear resistance of tungsten carbide insert was increased by shallow and deep cryogenic treatments.
Effects of cryogenically treated physical vapor deposition-coated tools on the turning performance of nickel-based superalloy
(Sage Publications Ltd, 2023) Gokkaya, Hasan; Akincioglu, Sitki
In recent years, cryogenic treatment has been applied to improve the performance of cutting tools. Improving the performance of cutting tools can improve the surface qualities of workpiece and reduce costs. Nickel-based superalloys are difficult to machine. It is necessary to improve the machinability properties of these hard-to-machine alloys and to increase the product quality. In this study, the effects of cryogenically treated physical vapor deposition-coated tools on the turning performance of nickel-based Hastelloy C22 superalloy were investigated. Deep cryogenic treatment (-145 degrees C) and shallow cryogenic treatment (-80 degrees C) were applied to the physical vapor deposition-coated tools. Experiments were carried out under dry conditions. The cutting parameters selected for the machining were cryogenically treated cutting tools, cutting speed, and feed rate. The deep cryogenic treatment had a favorable influence on the performance of the physical vapor deposition-coated carbide inserts. Thanks to the deep cryogenic treatment applied to the cutting tools, 99.5% and 19.7% improvement in surface roughness and cutting forces were achieved, respectively, compared to the untreated tool. The deep cryogenic treatment contributed more to the wear resistance of the tools than the shallow cryogenic treatment. A slight increase in the hardness and electrical conductivity of the tools was detected thanks to the cryogenic treatment.
The Effects of Machining Parameters on Cutting Forces, Surface Roughness, Built-Up Edge (BUE) and Built-Up Layer (BUL) During Machining AA2014 (T4) Alloy
(Assoc Mechanical Engineers Technicians Slovenia, 2010) Gokkaya, Hasan
Tool wear, formed in cutting tool during machining processes, affects the surface roughness of the work piece, cutting forces and other output parameters. The effects of the machining parameters cutting speed (V(c)) and the feed rate (f) on built-up edge (BUE), built-up layer (BUL), main cutting force (F(c)), and surface roughness (R(a)) is investigated in this study. The effects of the cutting parameters on cutting force and surface roughness has been examined by the use of Variance Analysis (ANOVA); and their optimum and critical cutting parameters were determined accordingly. AA2014 aluminum alloy was machined with uncoated carbide tools using Computer Numerical Control (CNC) turning machine under dry cutting conditions. Four different cutting speeds (200 m/min, 300 m/min, 400 m/min, and 500 m/min), five different feed rates (0.10 mm/rev, 0.15 mm/rev, 0.20 mm/rev, 0.25 mm/rev, and 0.30 mm/rev) and a constant depth of cut were selected as the machining parameters. BUE and BUL in the cutting tool were formed most at cutting speed 200 m/min and feed rate 0.30 mm/rev. The lowest cutting force was determined as 137 N at cutting speed 500 m/min and feed rate 0.10 mm/rev. The lowest average surface roughness, however, was determined as 0.93 mu m at 500 m/min cutting speed and feed rate 0.10 mm/rev. (C)2010 Journal of Mechanical Engineering. All rights reserved.
Effects of machining parameters on surface roughness and macro surface characteristics when the machining of Al-6082 T6 alloy using AWJT
(Elsevier Sci Ltd, 2017) Kartal, Fuat; Yerlikaya, Zekeriya; Gokkaya, Hasan
This study analyzes the effects of machining parameters on the surface roughness and macro surface characteristics when machining Al-6082 T6 alloy of empty set30 and 240 mm in size using abrasive water jet (AWJ) turning processes. The material removal tests were conducted using a computer numerical control (CNC) abrasive jet cutting machine for different parameters of nozzle feed rate (10, 15, 20 and 25 mm.min(-1)), abrasive flow rate (50, 150, 250 and 350 g.min(-1)), spindle speed (25, 50, 75 and 100 min(-1)) and standoff distance (2, 5, 8 and 11 mm). Pump pressure at 350 MPa, abrasive type of Garnet and size of 120 Mesh, and nozzle diameter of 0.75 mm are kept constant throughout the experiments. When macro surface characteristics were analyzed, it was found that increased spindle speed, decreased nozzle feed rate, increased abrasive flow rate and lower standoff distance resulted in smoother surfaces. According to the findings of this study, best results were obtained when spindle speed and abrasive flow rate were increased. (C) 2016 Elsevier Ltd. All rights reserved.
Evaluation of corrugated core configuration effects on low-velocity impact response in metallic sandwich panels
(Walter De Gruyter Gmbh, 2024) Zurnaci, Erman; Gokkaya, Hasan
Sandwich panels are used as body components of vehicles in many sectors, such as defense, aircraft, and aviation, due to their advanced mechanical properties and lightness. This study aims to investigate the effect of core configurations on mechanical performance and deformation behavior of metallic sandwich panels under low-velocity impact loading. For this purpose, metallic sandwich panels having monolithic and sliced core configurations were first produced. Low-velocity impact tests were carried out using varying energy levels (20, 40, 60 J) to examine how the intensity of influence affects the deformation of the sandwich panel. The perforation and deformation behavior on the upper surface plates of sandwich panels were evaluated. Experimental results showed that the core design significantly affects the impact behavior of sandwich panel samples. The sliced core configuration produced approximately 10 % more maximum contact force and absorbed 14 % more impact energy at high-impact energy levels. Additionally, the sliced core configuration delayed core collapse of the core in deformation situations where complete perforation does not occur.
Experimental and Statistical Study on Machinability of the Composite Materials with Metal Matrix Al/B4C/Graphite
(Springer, 2017) Nas, Engin; Gokkaya, Hasan
In this study, four types of Al/B4C/Graphite metal matrix composites (MMCs) were produced by means of a hot-pressing technique with reinforcement elements, B4C 8 wt pct and graphite (nickel coated) 0, 3, 5, and 7 wt pct. Machinability tests of MMC materials thus produced were conducted using four different cutting speeds (100, 140, 180, and 220 m/min), three different feed rates (0.1, 0.15, and 0.20 mm/rev), and a fixed cutting depth (0.5 mm), and the effects of the cutting parameters on the average surface roughness were examined. After the machinability tests, the height of the built-up edge (BUE) formed on the cutting tools related to the cutting speed and feed rate was measured. The test results were examined by designing a matrix according to the full factorial design and the average surface roughness, and the most important factors leading to formation of the BUE were analyzed by the analysis of variance (ANOVA). As a result of analysis, it was found that the lowest surface roughness value was with 7 wt pct graphite MMC material, while the highest was without graphite powder. Based on the statistical analysis results, it was observed that the most important factor affecting average surface roughness was the type of MMC material, the second most effective factor was the feed rate, and the least effective factor was the cutting speed. Furthermore, it was found that the most important factor affecting the formation of the BUE was the type of MMC material, the second most effective factor was the cutting speed, and the least effective factor was the feed rate.
Experimental investigation of the effects of aging and cryogenic treatments on the mechanical properties of superelastic nickel-titanium shape-memory alloys
(Sage Publications Ltd, 2022) Guven, Sedat; Altin Karatas, Meltem; Gokkaya, Hasan; Akinay, Yuksel
In this study, electropolishing and two different heat treatments were applied to wires made of superelastic nickel-titanium (NiTi) shape-memory alloy (SMA) and their mechanical properties and stress-induced deformations were investigated. In experimental studies, cryogenic and aging heat treatments were applied to NiTi SMA wire samples and tensile test experiments were carried out to determine the effect of the heat treatments on their mechanical properties. Following the tensile test experiments conducted at room temperature (23 degrees C), the study investigated changes in the elemental composition, fracture modes, micro cracks, and phase structures and in the mechanical properties formed in the fracture region. Intermetallic phase structures (Ti2Ni, Ni3Ti, and Ni4Ti3) were observed in the X-ray diffraction (XRD) analyses. It was concluded that the aging heat treatment had directly affected the reduction in hardness. In particular, in samples without the aging heat treatment, a stress-induced decrease in the Ni and Ti ratios and an increase in the carbon (C) ratio were observed in the chemical composition of the fracture surface of the superelastic NiTi SMA wires. It was determined that the changes in the chemical composition caused by stress had affected the mechanical properties negatively. In the fractography of the NiTi SMA wires, the samples exhibited mostly ductile fracture behavior with small dimples.
AN EXPERIMENTAL STUDY ON THE EFFECTS OF THE THERMAL BARRIER PLATING OVER ENGINE FUEL CONSUMPTION EXHAUST TEMPERATURE AND EMISSIONS
(Pamukkale Univ, 2014) Gurbuz, Huseyin; Gokkaya, Hasan
The aim of this study, the combustion chamber elements of a one-cylinder diesel engine which is air-cooled, single-cylinder, direct injection, 4-stroke and starter motor were plated with thermal barrier plating and tested with diesel fuel between the speeds of 1600 1/min to 3200 1/min and determined the effects of the thermal barrier plating on the engine exhaust gas temperature, emissions and fuel consumption. Increase in the temperature of the exhaust gas, decrease in HC and CO emissions that are harmful to the environment and living things and improvement in fuel consumption were observed.
Finite element simulation and experimental investigation on the effect of temperature on pseudoelastic behavior of perforated Ni-Ti shape memory alloy strips
(Iop Publishing Ltd, 2022) Altas, Emre; Khosravi, Farshid; Gokkaya, Hasan; Arab Maleki, Vahid; Akinay, Yuksel; Ozdemir, Okan; Bayraktar, Omer
In the present study, the temperature-dependent pseudoelastic behavior of shape memory alloy (SMA) sheets is studied experimentally and by finite element (FE) modeling. For this purpose, temperature-dependent mechanical properties for Ni-Ti alloy materials are first obtained by using direct tensile and three-point bending experiments at 23 degrees C, 50 degrees C, and 80 degrees C temperatures, respectively. The structure of these materials is examined at different temperatures using SEM images and the XRD test. Furthermore, using the FE model, the pseudoelastic behavior and the effect of temperature on the residual deflection of the prose-shape memory strips with a circular hole under three-point bending loads are studied. After validating the results of the FE model with the results of experimental tests, the effects of various parameters such as the diameter and number of holes on residual deformation and residual strains are investigated. The results show that with increasing temperature, the mechanical properties including the tensile strength, Young's modulus, yield stress, and flexural strength of SMA strips increase significantly. For solid strips, although increasing the temperature increases the maximum flexural force, in contrast, it reduces the flexural stiffness. In solid strips, flexural stiffness decreases by 5.5% with increasing temperature from 23 degrees C to 80 degrees C.
INVESTIGATION OF ELECTROEROSION MACHINING PERFORMANCE OF METAL MATRIX COMPOSITE MATERIALS PRODUCED USING STIR AND INDIRECT SQUEEZE METHOD
(World Scientific Publ Co Pte Ltd, 2023) Ugur, Abdullah; Nas, Engin; Gokkaya, Hasan
In this study, metal matrix composite (MMC) materials were made with an aluminum matrix (AA7075 alloy) and reinforcement silicon carbide (SiC) elements using molten metal stir and indirect squeeze casting. SiC was used as a reinforcing element in the making of MMC material in different amounts (10%, 14%, and 18%) by mass. Electro Discharge Machining (EDM), cut depth (0.5 mm), three different pulse-on times, three different discharge current values, and a fixed pulse-off time (20 s) were used to machine MMC materials. The effects of machining parameters on machining time, average surface roughness, hole diameter, and material wear difference after machining were studied. As a result of the study, the composite material with 75 mu s pulse-on time, 6A current value, and 10% reinforcement element had the lowest machining time, the largest hole diameter, and the smoothest average surface. These machining parameters and materials also had the shortest machining time (5 min). Based on the signal-to-noise ratios, the best parameters for average surface roughness, hole diameter, Processing time, and material wear amount (MMC, discharge current value, and impact time) were found to be L2L1L1, L3L1L1, L1L3L3, and L1L1L2, respectively. Based on the ANOVA results, the R2 values for the average surface roughness, hole diameter, machining time, and material wear loss value were 99.3%, 98.7%, 77.8%, and 97.3%, respectively.
Investigation of photochemical machining characteristics of stainless steel AISI 304 via novel PCM equipment design
(Emerald Group Publishing Ltd, 2022) Tunc, Murat; Gokkaya, Hasan; Sur, Gokhan; Motorcu, Ali Riza
Purpose The purpose of the paper is to investigate photochemical machining characteristics of stainless steel (AISI 304-SS304) parts with a novel design are investigated experimentally from the aspect of process parameters. The effects of phototool pattern geometry, ultraviole (UV) exposure time and etching time on of AISI 304 were evaluated. Design/methodology/approach The designed semi-automated photochemical manufacturing (PCM) equipment consists of 4 units, which include UV exposure, etching, developing and surface cleaning units. Experimental procedure has been designed via Taguchi method. Results were evaluated via Analysis of Variance (ANOVA) method. Findings Etching time is the most effective factor in PCM quality of AISI 304 stainless steel. Surface roughness is sensitive to geometrical pattern of the phototool for PCM of AISI 304 UV exposure time is less influential on the PCM quality for stainless steel. Research limitations/implications The designed PCM equipment prototype is not fully automated, which requires automation for part replacements into units. The effects of the temperature inside chemical processing units on process characteristics cannot be evaluated due to equipment limitations. The effects of surface cleaning time inside surface cleaning unit are not analyzed. Originality/value The utilized PCM equipment is semi-automated equipment, with which the process parameters such as etching time, surface cleaning time, UV exposure time and developing time can be controlled. Different from literature, the effects of phototool pattern geometries on the photochemical machining quality parameters are evaluated for the processing of AISI 304. The effects of processing parameters on dimensional accuracy, which is not common in the literature for AISI 304 stainless steel, are also evaluated.
Investigation of the effect of AWJ drilling parameters for delamination factor and surface roughness on GFRP composite material
(Emerald Group Publishing Ltd, 2022) Altin Karatas, Meltem; Gokkaya, Hasan; Akincioglu, Sitki; Biberci, Mehmet Ali
Purpose The purpose of this study is to optimize processing parameters to get the smallest average surface roughness (Ra) and delamination damage (F-d) values during drilling via abrasive water jet (AWJ) of the glass fiber-reinforced polymer composite material produced at [0 degrees/90 degrees](s) fiber orientation angles. Design/methodology/approach Drilling experiments were done via AWJ with three-axis computer numerical control (CNC) control system. Machine processing parameters such as water pressure of 3,600, 4,300, 4,800 and 5,300 bar; stand-off distance of 1, 2, 3 and 4 mm; traverse rate of 750, 1,500, 2,000 and 3,000 mm/min; and hole diameters of 8, 10, 12 and 14 mm have been selected. The effects of processing parameters in drilling experiments were investigated in conformity with the Taguchi L-16 orthogonal array and the data obtained were analyzed using Minitab 17 software. The signal/noise (S/N) ratio was taken as a basis for evaluating the test results. Optimum processing conditions were determined by calculating the S/N ratio for both Ra and F-d in conformity with the smaller is better approximation. The effects of processing parameters on Ra and F-d were statistically investigated using analysis of variance, S/N ratio and Taguchi-based gray relational analysis. Ra and F-d were predicted by evaluating with the ANN model and were predicted with the least amount of error. Findings It has been determined that the most effective parameter for Ra and F-d is the water pressure and then the stand-off distance. Originality/value The novel approach is to reduce cost and the time spent by using Taguchi optimization as a result of AWJ drilling the material in this fiber orientation [0 degrees/90 degrees](s).
Investigation of the machinability of SiC reinforced MMC materials produced by molten metal stirring and conventional casting technique in die-sinking electrical discharge machine
(Pergamon-Elsevier Science Ltd, 2020) Ugur, Abdullah; Nas, Engin; Gokkaya, Hasan
In this study, MMC materials were produced by stir casting method using AA7075 alloy matrix and silicon carbide (SiC) as reinforcement elements in order to investigate the effect of die-sinking electric discharge machining (EDM) process parameters for various weight percentage reinforcement (10% 14% and 18%) used MMC. EDM with three different pulse-on time (Time on) (25, 50 &75 mu s) and discharge current value (2, 4 & 6 Amperes) and at constant dwell time (20 mu s) and depth of cut (0.5 mm). After machining process, the effects of process parameters on processing time, average surface roughness, hole diameter and the weight loss were investigated. As a result of the study, highest values, the lowest values of processing time, hole diameter and average surface roughness were obtained for various weight percentage reinforcement MMC respectively. Ideal MMC, discharge current value and time-on duration for average surface roughness, hole diameter, processing time and material wear loss according to signal to noise ratio were determined. According to ANOVA results, R-2 values for the average surface roughness, hole diameter, processing time and material wear loss were calculated as 89.55%, 98.46%, 89.85% and 24.06% respectively.

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