Yazar "Ozan, Sermin" seçeneğine göre listele

Listeleniyor 1 - 6 / 6
  • [ X ]
    Öğe
    Application of ANN in the prediction of the pore concentration of aluminum metal foams manufactured by powder metallurgy methods
    (Springer London Ltd, 2008) Ozan, Sermin; Taskin, Mustafa; Kolukisa, Sedat; Ozerdem, Mehmet Sirac
    In this work, the effect of fabrication parameters on the pore concentration of aluminum metal foam, manufactured by the powder metallurgy process, has been studied. The artificial neural network (ANN) technique has been used to predict pore concentration as a function of some key fabrication parameters. Aluminum metal foam specimens were fabricated from a mixture of aluminum powders (mean particle size 60 mu m) and NaCl at 10, 20, 30, 40(wt)% content under a pressure of 200, 250, and 300 MPa. All specimens were then sintered at 630 degrees C for 2.5 h in argon atmosphere. For pore formation (foaming), sintered specimens were immersed into 70 degrees C hot running water. Finally, the pore concentration of specimens was recorded to analyze the effect of fabrication parameters (namely, NaCl ratio, NaCl particle size, and compacting pressure) on the foaming behavior of compacted specimens. It has been recorded that the above-mentioned fabrication parameters are effective on pore concentration profile while pore diameters remain unchanged. In the ANN training module, NaCl content (wt)%, NaCl particle size (mu m), and compacting pressure (MPA) were employed as inputs, while pore concentration % (volume) of compacts related to fabrication parameters was employed as output. The ANN program was successfully used to predict the pore concentration % (volume) of compacts related to fabrication parameters.
  • [ X ]
    Öğe
    The effect of the process temperature on the bondability in diffusion bonding of AISI 430 with nodular cast iron
    (Carl Hanser Verlag, 2006) Taskin, Mustafa; Ozan, Sermin; Kolukisa, Sedat
    The effect of process temperature on the bondability of stainless steel AISI 430 and nodular cast iron was studied. The diffusion bonding was investigated experimentally under a protective atmosphere at various temperatures and a prescribed constant pressure blow which would cause macro-deformation. Microstructure examinations were carried out with the help of optical microscopy, SEM and EDS. Hardness values were measured by HV scale under a load of 200 g. At the bond interface cross section, decarburized and dechromised regions were observed on the ductile cast iron side and the stainless steel side respectively. Best mechanical and metallurgical properties were observed for the specimen bonded at 1100 degrees C process temperature at 15 MPa, for 20 min. As a function of the process temperature elevation, an increase of graphite atoms, migrating towards the interface, and a reduction of graphite atoms at the nodular graphite diameters was noticed.
  • [ X ]
    Öğe
    The effect of the process temperature on the bondability in transient liquid phase (tlp) diffusion bonding of AISI 430 ferritic stainless steel with nodular (spheroid) cast iron using a copper interlayer
    (Carl Hanser Verlag, 2006) Ozan, Sermin; Taskin, Mustafa; Kolukisa, Sedat
    The effect of the process temperature on the bondability in the transient liquid phase (tlp) was studied. The diffusion bonding of AISI 430 with nodular cast iron using a copper interlayer was investigated experimentally under a protective atmosphere at various temperatures and at a defined constant blow pressure which would cause macro deformation. Microstructure examinations were carried out with the help of optical microscopy, SEM and EDS. Hardness values were measured by HV scale under a load of 150 g. At the bond interface, decarburized and dechromised regions were observed on the ductile cast iron side and stainless steel side respectively. Best mechanical and metallurgical properties were observed for the specimen bonded at 1100 degrees C for 20 min. As a function of an elevation of the process temperature, an increase in the amount of graphite atoms that migrated toward the interface and a reduction at the nodular graphite diameters was noticed.
  • [ X ]
    Öğe
    Effect of the sintering temperature on the coating of duplex stainless steel with Ni3Al
    (Carl Hanser Verlag, 2018) Cay, Vedat Veli; Kati, Nida; Ozan, Sermin; Cetin, Tayfun
    In this study, duplex stainless steel was coated with Ni3Al powder via self-propagating high-temperature synthesis (SHS) and the effect of the sintering temperature on the coating characteristics was investigated. An SEM electron microscope with EDX (energy dispersive X-ray spectroscopy) was used to examine the microstructure of samples that were coated according to the SHS method and likewise to detect the element content of the phases in the structure. Microhardness tests were conducted on the samples to determine the mechanical properties of the coated material. As a result of these studies, it was found that duplex stainless steel can be reliably coated with an Ni3Al intermetallic compound. The increase in sintering temperature within the given range significantly decreased the size of the disconnected area which completely disappeared.
  • [ X ]
    Öğe
    Mechanical Properties of Ferrochrome Based Hardfacing Layers Coated on AISI 1020 Steel Obtained by the Aid of Plasma Transfer Arc (PTA) Process
    (Carl Hanser Verlag, 2010) Cay, Vedat Veil; Ozan, Sermin; Topuz, Polat; Kolukisa, Sedat
    Mechanical properties of ferrochrome based hardfacing layers coated on AISI 1020 steel obtained by the aid of Plasma Transfer Arc (PTA) was experimentally studied. Ferrochrome powders were mixed with sodium silicate gel to avoid spreading. The mixture was laid to 1.5 x 8 x 100 mm slots machined on AISI 1020 steel. Hardfacing layer was performed by PTA process under pure Argon as protective gas with 130 A/20 V power supply. Scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), micro hardness and abrasive tests were employed for the evaluation of ferrochrome alloyed coating. Hardfacing was successfully performed under given conditions. Microstructural changes and formations (phases) significantly improved hardness, abrasive wear resistance and integrity of hardfacing layer.
  • [ X ]
    Öğe
    Radiographic inspection of AISI 420 steel friction welds
    (Carl Hanser Verlag, 2018) Kati, Nida; Cay, Vedat Veli; Ozan, Sermin; Caligulu, Ugur; Turkmen, Mustafa
    In this study, X-ray radiographic tests of AISI 420 steel welded by friction welding were studied. During the welding process, three different rotations, 700, 1000 and 1300, were employed while the other parameters such as friction pressure, friction time, upsetting-pressure and upsetting-duration were unchanged. After the completion of welding process, the welded joints were subjected to radiographic tests by X-raydiffraction. The result of the radiographic tests indicates that by increasing rotation speed the amount of flash and joining properties/performance increases in all samples. The best properties of the AISI 420 martensitic stainless steel joints were observed in samples welded at a rotation speed of 1300 (rpm). It has been determined that in harmony with the definition of welding defects and respective radiographic images, lack of fusion is the most common welding defect.