Browsing by Author "Ozturk, Fahrettin"
Now showing items 1-20 of 25
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Analysis of Forming Limit Diagrams of DP600 Steel at Various Deformation Speeds
Uysal, Emrah; Ozturk, Fahrettin (WILEY-V C H VERLAG GMBH, 2010)The forming limit diagrams (FLDs) of DP600 steel at various deformation speeds are experimentally investigated. Results show that forming limit diagram of the material at various deformation speeds is not significantly ... -
Analysis of tempering treatment on material properties of DIN 41Cr4 and DIN 42CrMo4 steels
Bayrak, Mustafa; Ozturk, Fahrettin; Demirezen, Mehmet; Evis, Zafer (ASM INT, 2007)DIN 41Cr4 and DIN 42CrMo4 materials have been widely used in automotive driving elements. Although 42CrMo4 is more expensive than 41Cr4, it is more preferable in terms of material properties. In this study, these two ... -
ARTIFICIAL-NEURAL-NETWORK PREDICTION OF HEXAGONAL LATTICE PARAMETERS FOR NON-STOICHIOMETRIC APATITES
Kockan, Umit; Ozturk, Fahrettin; Evis, Zafer (INST ZA KOVINSKE MATERIALE I IN TEHNOLOGIE, 2014)In this study, hexagonal lattice parameters (a and c) and unit-cell volumes of non-stoichiometric apatites of M-10(TO4)(6)X-2 are predicted from their ionic radii with artificial neural networks. A multilayer-perceptron ... -
Assessment of Electrical Resistance Heating for Hot Formability of Ti-6Al-4V Alloy Sheet
Ozturk, Fahrettin; Ece, Remzi Ecmel; Polat, Naki; Koksal, Arif (TRANS TECH PUBLICATIONS LTD, 2011)Ti-6Al-4V (Ti64) is the most commercially used heat treatable high strength/weight ratio, high corrosion, and thermal resistance alloy in titanium alloys. However, room temperature (RT) formability of this alloy is very ... -
Detailed Investigation of Forming Limit Determination Standards for Aluminum Alloys
Dilmec, Murat; Halkaci, H. Selcuk; Ozturk, Fahrettin; Turkoz, Mevlut (AMER SOC TESTING MATERIALS, 2013)In this study, experimental studies were conducted to evaluate the differences between the ASTM E2218-02 and ISO 12004-2 standards that are used for construction of the forming limit curve (FLC) and that made various ... -
EFFECT OF PRE-STRAINING ON THE SPRINGBACK BEHAVIOR OF THE AA5754-0 ALLOY
Toros, Serkan; Alkan, Mahmut; Ece, Remzi Ecmel; Ozturk, Fahrettin (INST ZA KOVINSKE MATERIALE I IN TEHNOLOGIE, 2011)This study presents the effect of pre-straining on the springback behavior of the AA5754-0 aluminum-magnesium (Al-Mg) alloy sheet under V bending by an experimental and finite-element simulation studies. Pre-straining ... -
EFFECT OF SHEET THICKNESS ON THE ANISOTROPY AND THICKNESS DISTRIBUTION FOR AA2024-T4
Dilmec, Murat; Halkaci, Huseyin Selcuk; Ozturk, Fahrettin; Turkoz, Mevlut (INST ZA KOVINSKE MATERIALE I IN TEHNOLOGIE, 2013)In this study, the effect of sheet thickness on the anisotropy and thickness distribution at room temperature (RT) was investigated for AA2024-T4 sheets. The anisotropy was determined using automated strain measurement ... -
The Effect of Strain-Rate Sensitivity on Formability of AA 5754-O at Cold and Warm Temperatures
Ozturk, Fahrettin; Pekel, Hakan; Halkaci, Huseyin S. (SPRINGER, 2011)Aluminum-magnesium (Al-Mg) alloys have been widely used in diverse applications ranging from automotive bodies to food processing industries because of their excellent high-strength-to-weight ratio, corrosion resistance, ... -
Effect of Warm Temperature on Springback Compensation of Titanium Sheet
Ozturk, Fahrettin; Ece, Remzi Ecmel; Polat, Naki; Koksal, Arif (TAYLOR & FRANCIS INC, 2010)In the present study, the effect of warm temperature on springback compensation of commercially pure grade 2 (CP2) titanium sheet is investigated. The results reveal that the springback is substantially reduced with ... -
Effects of aging parameters on formability of 6061-O alloy
Ozturk, Fahrettin; Esener, Emre; Toros, Serkan; Picu, Catalin R. (ELSEVIER SCI LTD, 2010)6XXX series aluminum-magnesium-silicon (Al-Mg-Si) alloys are medium strength alloys widely used as automotive body materials. The mechanical properties of these alloys are adjusted by performing age hardening heat treatments. ... -
Effects of anisotropic yield functions on prediction of forming limit diagrams of DP600 advanced high strength steel
Ozturk, Fahrettin; Toros, Serkan; Kilic, Suleyman (ELSEVIER SCIENCE BV, 2014)In recent years, numerous researchers have reported that the predicted forming limit diagrams strongly depend on the method of determining the material parameters used in the yield functions and the corresponding the shape ... -
THE EFFECTS OF MATERIAL THICKNESS AND DEFORMATION SPEED ON SPRINGBACK BEHAVIOR OF DP600 STEEL
Toros, Serkan; Kilic, Suleyman; Ozturk, Fahrettin (TRANS TECH PUBLICATIONS LTD, 2011)There is an increase trend in the use of advanced high strength steels in automotive industry due to a combination of high strength and good formability in order to achieve substantial weight reduction. Lightening by using ... -
Effects of sheet thickness and anisotropy on forming limit curves of AA2024-T4
Dilmec, Murat; Halkaci, H. Selcuk; Ozturk, Fahrettin; Livatyali, Haydar; Yigit, Osman (SPRINGER LONDON LTD, 2013)In this study, the effects of sheet thickness and anisotropy of AA2024-T4 on forming limit curve (FLC) are experimentally investigated according to ISO 12004-2 standard. A new limit strain measurement method is proposed ... -
EFFECTS OF THE ARTIFICIAL-AGING TEMPERATURE AND TIME ON THE MECHANICAL PROPERTIES AND SPRINGBACK BEHAVIOR OF AA6061
Polat, Aytekin; Avsar, Mustafa; Ozturk, Fahrettin (INST ZA KOVINSKE MATERIALE I IN TEHNOLOGIE, 2015)In this study, the effects of the artificial-aging temperature and time on the mechanical properties and springback behavior of AA6061 are investigated. The results reveal that the yield strength, the tensile strength and ... -
EFFECTS OF VARIATIONS IN ALLOY CONTENT AND MACHINING PARAMETERS ON THE STRENGTH OF THE INTERMETALLIC BONDING BETWEEN A DIESEL PISTON AND A RING CARRIER
Acar, Ahu Fahriye; Ozturk, Fahrettin; Bayrak, Mustafa (INST ZA KOVINSKE MATERIALE I IN TEHNOLOGIE, 2010)The intermetallic bonding between an aluminium alloy piston and a cast-iron ring carrier must be able to withstand prolonged exposure to the high-pressure and high-temperature environment of a diesel engine. Weak cohesion ... -
EVALUATION OF TENSILE PROPERTIES OF HIGH STRENGTH STEELS AT WARM TEMPERATURES AND VARIOUS STRAIN RATES
Ozturk, Fahrettin; Toros, Serkan; Bas, M. Hakan; Kilic, Suleyman (VERLAG STAHLEISEN MBH, 2008)The use of advanced high strength steels in automotive industry has been increased recently. Dual-phase (DP) high-strength steel, which is an advanced high strength steel, has gained great attention due to its high strength ... -
Finite Element Simulation of Diametral Strength Test of Hydroxyapatite
Ozturk, Fahrettin; Evis, Zafer; Toros, Serkan (AMER INST PHYSICS, 2010)In this study, the diametral strength test of sintered hydroxyapatite was simulated by the finite element software, ABAQUS/Standard. Stress distributions on diametral test sample were determined. The effect of sintering ... -
Flow curve prediction of Al-Mg alloys under warm forming conditions at various strain rates by ANN
Toros, Serkan; Ozturk, Fahrettin (ELSEVIER SCIENCE BV, 2011)This paper describes an approach based on artificial neural network (ANN) to identify the material flow curves of strain hardened 5083-H111 and 5754-O Al-Mg alloys at the temperature ranges from room temperature (RT) to ... -
INVESTIGATION INTO REASONS FOR MINIMUM MAJOR STRAIN OFFSETTING OF FORMING LIMIT CURVE OBTAINED WITH NAKAJIMA TEST FOR AA 2024-T4
Dilmec, Murat; Halkaci, Huseyin Selcuk; Ozturk, Fahrettin (GAZI UNIV, FAC ENGINEERING ARCHITECTURE, 2014)In a typical forming limit curve (FLC), the minimum major strain where the minor value is equal to zero is located at y axes. In many forming processes, failure occurs at this region. Many studies in literature indicates ... -
An Investigation of Use Biaxial Data in Sheet Metal Forming Simulations
Esener, Emre; Ozturk, Fahrettin; Yenice, Mustafa (WILEY-V C H VERLAG GMBH, 2010)The use of biaxial data in sheet metal forming simulation of a DP600 steel sheet is investigated. The biaxial strain data is experimentally determined and the stresses are calculated by the inverse finite element method. ...
