Browsing by Author "Kartal F."

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A review of the current state of abrasive water-jet turning machining method
(2017-01-01) Kartal F.
Abrasive water-jet turning (AWJT) is one of these alternative methods and has gained an important status among others in a very short period of time. AWJT becomes prominent with its flexibility in cutting materials with almost any properties, with the elimination of thermal effects during the process, and with minimal stresses it imposes. It is widely preferred when heat-affected zones are to be avoided as it is a cold process. AWJT, on the other hand, is the replacement of a traditional cutter head of a turning testing apparatus with the AWJ in order to remove material turning the workpiece using a spindle testing apparatus while moving the nozzle on an axis with a specific distance from the workpiece. It is convenient to machine planar workpieces using the AWJ while it is harder to machine (turn) workpieces. However, there are scientific studies on the machinability of the planar workpieces, studies on the machinability of cylindrical materials are rarely found in the literature. Among the machining parameters for AWJT are nozzle feed rate, spindle speed, abrasive flow rate, pump pressure, abrasive size, and standoff distance. The studies available in the literature focus on the impact on Ra (μm), machining depth (mm), and material removal rate (mm3 min−1) as experiment outcomes. In this study, reviews of the research are available in the literature on the turning of workpieces using abrasive water jet. This study will also discuss the recommendations for the future research.
A review of the current state of abrasive water-jet turning machining method
(2017-01-01) Kartal F.; Kartal, F
Abrasive water-jet turning (AWJT) is one of these alternative methods and has gained an important status among others in a very short period of time. AWJT becomes prominent with its flexibility in cutting materials with almost any properties, with the elimination of thermal effects during the process, and with minimal stresses it imposes. It is widely preferred when heat-affected zones are to be avoided as it is a cold process. AWJT, on the other hand, is the replacement of a traditional cutter head of a turning testing apparatus with the AWJ in order to remove material turning the workpiece using a spindle testing apparatus while moving the nozzle on an axis with a specific distance from the workpiece. It is convenient to machine planar workpieces using the AWJ while it is harder to machine (turn) workpieces. However, there are scientific studies on the machinability of the planar workpieces, studies on the machinability of cylindrical materials are rarely found in the literature. Among the machining parameters for AWJT are nozzle feed rate, spindle speed, abrasive flow rate, pump pressure, abrasive size, and standoff distance. The studies available in the literature focus on the impact on Ra (μm), machining depth (mm), and material removal rate (mm3 min−1) as experiment outcomes. In this study, reviews of the research are available in the literature on the turning of workpieces using abrasive water jet. This study will also discuss the recommendations for the future research.
Determination of fatigue life and failure location of vehicle cylindrical LPG fuel tanks
(2016-01-01) Kartal F.; Kişioǧlu Y.
This study addresses the determination of the fatigue life and its failure locations of the vehicle cylindrical LPG fuel tanks using both experimental and finite element analysis (FEA) methods. The experimental investigations performed as an accelerated fatigue tests are carried out using a hydraulics test unit in which the cylinders are internally pressurized by hydraulic oil. The LPG cylinders are subjected to repeated cyclic pressure varying from zero to service pressure of the tank. The FEA modeling of these tanks are developed in three dimensional (3D) using non-uniform geometrical parameters and nonlinear material properties. These models are also subjected to zero-based high cycle fatigue pressure load considering the stress life approach. The FEA modeling process is also simulated in non-homogeneous material conditions. Therefore, the fatigue life performance and failure location of the cylindrical LPG fuel tanks are predicted and compared to the experimental results.
Effect of abrasive water jet turning parameters on depth of cut of AISI 1050 steel
(2014-01-01) Kartal F.; Gökkaya H.
This study analyzes the depth of cut as an output of experiments using abrasive water jet turning (AWJT) on AISI 1050 steel material and machining parameters were optimized using Taguchi method. Three different nozzle feed rates (0.01, 0.017 and 0.09 mm/min), abrasive mass flow rates (50, 200 and 350 g/min), lathe spin rates (500, 1500 and 2500 rpm), nozzle distances (2,10 and 18 mm) and two different nozzle diameters (0.75 and 1.3 mm) were used as machining parameter values. Taguchi's LI8 orthogonal array was adopted for the test design. The impact of parameters on depth of cut was statistically examined using analysis of variance and S/N ratios obtained. As a result of the tests, Nozzle feed rate proved to have the highest impact on the depth of cut with its rate of 75.38%. Using a 0.75 mm nozzle diameter led to decreased depth of cut. Increasing the spindle speed proved to increase the depth of cut.
Effect of abrasive water jet turning process parameters on surface roughness and material removal rate of AISI 1050 steel
(2015-01-01) Kartal F.; Gökkaya H.
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 × min^-1), and spindle speed (500,1500 and 2500 min^-1), regarding machining efficiency parameters, namely, average surface roughness Ra (μm) and material removal rate (mm³ × min^-1), using AISI 1050 steel workpieces machined by abrasive water jet turning. Taguchi L18(2¹ × 3⁴) 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.
Effects of machining parameters on surface roughness and macro surface characteristics when the machining of Al-6082 T6 alloy using AWJT
(2017-01-01) Kartal F.; Yerlikaya Z.; Gökkaya H.
This study analyzes the effects of machining parameters on the surface roughness and macro surface characteristics when machining Al-6082 T6 alloy of ∅30 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.
Evaluation of explosion pressure of portable small liquefied petroleum gas cylinder
(2020-06-01) Kartal F.; Kartal, F
This study aims to estimate the explosive pressures and permanent volume expansion of liquefied petroleum gas (LPG) portable small LPG cylinder fuel tanks using experimental and finite element analysis (FEA) approaches. Experimental explosion testing was carried out by means of a hydrostatic device in which the cylinders were pressurized with water. LPG tanks are subjected to increased internal equal pressure in FEA modeling. Three-dimensional nonlinear models were developed and evaluated under irregular boundary conditions. For analysis, the required real shell properties including the source region and thickness variations were investigated. Therefore, the results of burst pressures and volume expansions are predicted and compared with the experimental ones. The results of finite element method showed similar results with the results obtained from the experiments. The results provide a description of the stages of the explosion and the hazards arising from the damage to the tanks.
Evaluation of explosion pressure of portable small liquefied petroleum gas cylinder
(2020-06-01) Kartal F.
This study aims to estimate the explosive pressures and permanent volume expansion of liquefied petroleum gas (LPG) portable small LPG cylinder fuel tanks using experimental and finite element analysis (FEA) approaches. Experimental explosion testing was carried out by means of a hydrostatic device in which the cylinders were pressurized with water. LPG tanks are subjected to increased internal equal pressure in FEA modeling. Three-dimensional nonlinear models were developed and evaluated under irregular boundary conditions. For analysis, the required real shell properties including the source region and thickness variations were investigated. Therefore, the results of burst pressures and volume expansions are predicted and compared with the experimental ones. The results of finite element method showed similar results with the results obtained from the experiments. The results provide a description of the stages of the explosion and the hazards arising from the damage to the tanks.
Fatigue Performance Evaluations of Vehicle Toroidal Liquefied Petroleum Gas Fuel Tanks
(2017-08-01) Kartal F.; Kisioglu Y.
In this study, fatigue performances of the vehicle toroidal liquefied petroleum gas (LPG) fuel tanks were examined to estimate the fatigue life and its failure locations using both experimental and finite element analysis (FEA) methods. The experimental investigations performed as accelerated fatigue tests were carried out using a hydraulics test unit in which the tanks were internally pressurized by hydraulic oil. The LPG tanks were subjected to repeated cyclic pressure load varying from zero to service pressure (SP) of the tank. The computerized FEA modeling of these tanks were developed in three-dimensional (3D) form using nonuniform geometrical parameters and nonlinear material properties. These models were also subjected to zero-based high cycle fatigue pressure load considering the stress life approach. The FEA modeling process was also simulated in nonhomogeneous material conditions. Therefore, the fatigue life performance and failure location of the toroidal LPG fuel tanks were predicted using the computer-aided simulations and compared with the experimental results.
High-quality c-axis oriented non-vacuum Er doped ZnO thin films
(2016-05-15) Asikuzun E.; Ozturk O.; Arda L.; Tasci A.; Kartal F.; Terzioglu C.
Preparation, growth, structure and optical properties of high-quality c-axis oriented non-vacuum Er doped ZnO thin films were studied. Zn1-xErxO (x=0.0, 0.01, 0.02, 0.04, and 0.05) precursor solutions were prepared by sol-gel synthesis using Zn, and Er based alkoxide which were dissolved into solvent and chelating agent. Zn1-xErxO thin films with different Er doping concentration were grown on glass substrate using sol-gel dip coating. Thin films were annealed at 600 °C for 30 min, and tried to observe the effect of doping ratio on structural and optical properties. The particle size, crystal structure, surface morphologies and microstructure of all samples were characterized by X-Ray diffraction (XRD) and Scanning Electron Microscope (SEM). The UV-vis spectrometer measurements were carried out for the optical characterizations. The surface morphology of the Zn1-xErxO films depend on substrate nature and sol-gel parameters such as withdrawal speed, drying, heat treatment, deep number (film thickness) and annealing condition. Surface morphologies of Er doped ZnO thin films were dense, without porosity, uniform, crack and pinhole free. XRD results showed that, all Er doped ZnO thin films have a hexagonal structure and (002) orientation. The optical transmittance of rare earth element (Er) doped ZnO thin films were increased. The Er doped ZnO thin films showed high transparency (>85) in the visible region (400-700 nm).
Investigation of surface roughness and MRR for engineering polymers with the abrasive water jet turning process
(2016-07-01) Kartal F.; Yerlikaya Z.
This study investigates the abrasive water jet turning (AWJT) process of commonly used plastics, such as polytetrafluoroethylene (PTFE), castamide, and polyamide (PA), in engineering. Machining parameters were used as follows: nozzle feed rate (10, 30, and 50 mm min−1), abrasive flow rate (50, 250, and 450 g min−1), and spindle speed (1 000, 2 000, and 3 000 min−1). The effects of the machining parameters on the average surface roughness and material removal rate were investigated. According to results, average surface roughness and material removal rate were affected by the nozzle feed rate by 87.15 % and 82.48 %, abrasive flow rate by 9.84 % and 13.49 %, and spindle speed by 1.09 % and 0.08 %, respectively. Optimization results that the nozzle feed rate should be 10 mm min−1, while the abrasive flow rate is 450 g/min and spindle speed is 3 000 min−1 in order to obtain the minimum surface roughness and maximum material removal rate.
Non–traditional machining of inconel 600 material
(2019-01-01) Kartal F.; Hloch S.
Abrasive water jet machining (AWJM) is successfully used for various industrial applications to cut extreme ductile and brittle materials. Thermal deterioration, high processing diversity, provide distinct advantages with high flexibility and small cutting forces. In this study, the Taguchi design analysis was used to determine the optimal combination of parameters for the actual cutting conditions of the Inconel 600 material. Variance Analysis (ANOVA) was also used to determine the most important factor. Common parameters such as nozzle feed rate, nozzle standoff distance and abrasive flow rate are optimized to investigate the effects of parameters on the Surface Roughness (Ra) during cutting of the Inconel 600 material.
Optimization of abrasive water jet turning parameters for machining of low density polyethylene material based on experimental design method
(2014-01-01) Kartal F.; Çetin M.H.; Gökkaya H.; Yerlikaya Z.
Studies to improve the machining of engineering materials have great importance for mechanical systems. Abrasive water-jet turning (AWJT) is a new and effective process for increasing machinability of engineering materials by providing temperature free cutting conditions, high surface quality and having no tool wear problem. In this study, AWJT of low density polyethylene (LDPE) material were investigated in terms of average surface roughness (ASR) and material removal rate (MRR) values and process parameters were optimized by experimental design method. The primary objectives of the study are to investigate AWJT process and system parameters to enhance machinability of LDPE material and to determine optimal processing parameters. Nozzle feed rate (5, 25 and 45 mm/min), abrasive flow rate (50, 200 and 350 g/min) and spindle speed (1000, 1500 and 2500 min^-1) were analyzed as process parameters. Taguchi L27 orthogonal full factorial design, optimization box and analysis of variance (Anova) were used for the experimentation and results analysis. Experimental results show that, AWJT process is more efficient in the machining of LPDE material than the conventional machining methods by increasing surface quality and MRR parameters. Minimum ASR and maximum MRR were obtained 1.67 lm and 14072.02 mm³/min respectively; at optimum parameters of 5 mm/min nozzle feed rate, 350 g/ min abrasive flow rate and 2500 min^-1 spindle speed. © Carl Hanser Verlag, Munich.
Performance evaluation of the submerged abrasive water jet turning process for improving machinability of castamide
(2020-08-01) Ibrahim S.A.B.; Korkmaz S.; Cetin M.H.; Kartal F.
In this study, the submerged abrasive water jet turning (AWJT) system was used for improving machinability of castamide material and process parameters have been investigated comprehensively. Optimum parameters were determined as to minimize the surface roughness and maximize the material removal rate in the submerged turning process of castamide. 3-level traverse speed (TS), abrasive flow rate (AFR) and spindle speed (SS) were taken as the input parameters, and the experimental design was made as a full factorial design. The effect ratios of the input parameters were analyzed statistically by ANOVA and graphical methods, and their interactions were examined by 3D surface images. Optimum test condition was determined by TOPSIS and VIKOR methods. Experimental results were compared with conventional abrasive water jet process. In addition, regression equations were obtained for the explanation of the experimental results mathematically to show the relationships between the variables. According to the experimental results, submerged AWJT increased the surface roughness of castamide material by 15% compared to conventional AWJT and decreased the metal removal rate by 5.22%. ANOVA results showed that the traverse speed is the most effective parameter on the machinability of castamide. Traverse speed was found to be 83.11% effective on surface roughness and 85.56% on material removal rate. According to TOPSIS and VIKOR optimization results, 40 mm/min TS, 310 g /min AFR and 300 rpm SS values were determined as the optimum test conditions.
Study and evaluation of abrasive water jet turning process performance on AA5083
(2020-02-01) Kartal F.
In this study, the effect of processing parameters on surface roughness and macro surface characteristics was analyzed during the machining of Ø30 mm and 300 mm aluminum alloy AA5083 abrasive water jets. As the processing parameters (up to 10 mm min−1, 15 mm min−1, 20 mm min−1 and 25 mm min−1), abrasive flow rate (50 g min−1, 150 g min−1, 250 g min−1 and 350 g min−1), the lathe chuck rotational speed (25 min−1, 50 min−1, 75 min−1 and 100 min−1) and the nozzle approach distance (2 mm, 5 mm, 8 mm and 11 mm) were used in experiments. In experimental studies, the pump pressure (360 MPa) was used as a constant, in the form of an abrasive Garnet (100 mesh), and the nozzle diameter as 0.76 mm. According to the findings, the best results in terms of surface roughness were obtained as a result of turning speed and abrasive flow rate. When the macro surface characteristics were examined, it was found that the lathe chuck rotational speed increased, the rate of nozzle progression was low, the rate of abrasive flow was high and the nozzle approach distance was lower and the smoother surfaces were obtained.
Study and evaluation of abrasive water jet turning process performance on AA5083
(2020-02-01) Kartal F.; Kartal, F
In this study, the effect of processing parameters on surface roughness and macro surface characteristics was analyzed during the machining of Ø30 mm and 300 mm aluminum alloy AA5083 abrasive water jets. As the processing parameters (up to 10 mm min−1, 15 mm min−1, 20 mm min−1 and 25 mm min−1), abrasive flow rate (50 g min−1, 150 g min−1, 250 g min−1 and 350 g min−1), the lathe chuck rotational speed (25 min−1, 50 min−1, 75 min−1 and 100 min−1) and the nozzle approach distance (2 mm, 5 mm, 8 mm and 11 mm) were used in experiments. In experimental studies, the pump pressure (360 MPa) was used as a constant, in the form of an abrasive Garnet (100 mesh), and the nozzle diameter as 0.76 mm. According to the findings, the best results in terms of surface roughness were obtained as a result of turning speed and abrasive flow rate. When the macro surface characteristics were examined, it was found that the lathe chuck rotational speed increased, the rate of nozzle progression was low, the rate of abrasive flow was high and the nozzle approach distance was lower and the smoother surfaces were obtained.
Tensile test specimen preparing three different cutting method influence on the AA 6061-T6
(2014-01-01) Kartal F.; Gokkaya H.; Yerlikaya Z.; Polat R.
Aluminum 6061 (T6) material which is widely used in aviation and defense industries was treated with tensile test in this study. The samples for tensile test were manufactured using three production methods (namely, milling, CO2laser and abrasive water jet (AWJ). Following the tests sample surfaces were assessed for their surface roughness values. Samples which meet the TS EN ISO 6892-1 standard were assessed for their tensile strength, yield strength, percentage elongation and constriction. Among the test samples, sample prepared by milling proved to provide the best surface roughness value (1.32 μm). The highest tensile strength was obtained from the sample prepared using AWJ while the lowest was obtained from the sample prepared using laser cutting. Samples prepared using abrasive water jet showed 6.57 % difference in terms of tensile strength from samples prepared using milling.
The impact of machining parameters on the surface roughness and depth of cut while cutting Inconel 718 super alloy using abrasive water jet
(2016-01-01) Kartal F.
Inconel Alloy 718 super alloy was machined using abrasive water jet (AWJ) in this study. Following the cutting process, average surface roughness (Ra µm) and material removal rate (MRR) were investigated and operating parameters were optimized using Taguchi method. Among the machining parameters were pump pressure (PP) (200, 350 MPa), nozzle feed rate (NFR) (5, 105 and 205 mm/min); abrasive flow rate (AFR) (50, 200 and 350 g/min); spindle speed (SS) (25, 50 and 75 RPM) and standoff distance (SOD) (2, 8 and 14 mm). Taguchi L18 (21 x34) orthogonal factorial experiment organization is adopted as experiment design. The effect of parameters on Ra and depth of cut (DoC) was investigated statistically using the outcomes of the variance analysis and S/N rates. As a result of the empirical studies, PP proved to have the highest effect on Ra by 42.35%. On the other hand, NFR proved to have the highest effect on DoC by 72.85%. Increasing SS has improved Ra value while increasing DoC.
Turning of (Cu-Cr-Zr) alloy with abrasive water jet
(2012-12-01) Kartal F.; Gokkaya H.; Nalbant M.
In this research, the effect of the processing parameters on surface roughness during the turning of (Cu-Cr-Zr) alloy with abrasive water jet was studied. In the experimental studies, (Cu-Cr-Zr) alloy, ∅30 and 240 mm in size, was processed with abrasive water. In the experiment, pump pressure was 350 MPa, in the form of garnet abrasive and 80 mesh in size and nozzle diameter were kept constant at 1.2 mm. In addition to that in the parameters of nozzle feed rates (10, 15, 20 and 25 mm/min), abrasive flow rates (50, 150, 250 and 350 gr/min) and nozzle distances (2, 5, 8, 11 mm) were used in the tests. According to the results of the experiment, the increase in nozzle feed rate and nozzle distance lead to increase in average surface roughness. On the other hand, the increase in the number of turning speed and abrasive flow rate lead to decrease in average surface roughness. Average surface roughness was measured between 2.5 and 5.5 μm. © BHR Group 2012 Water Jetting 21.