Yazar "Gungunes, H." seçeneğine göre listele

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    Effect of Si on austenite stabilization, martensite morphology, and magnetic properties in Fe-26%Ni-x%Si alloys
    (Springer, 2011) Gungunes, H.; Yasar, E.; Dikici, M.
    The effect of Si on the austenite stabilization, martensite morphology, and magnetic properties in Fe-26%Ni-x%Si (x=3.5, 5, and 6) alloys have been studied by means of transmission electron microscopy (TEM) and Mossbauer spectroscopy techniques. TEM observations reveal that the martensite morphology is closely dependent on the Si content. The volume fraction changes of martensite and austenite phases, the hyperfine magnetic field, and isomer shift values have been determined by Mossbauer spectroscopy. The Mossbauer study reveals that the hyperfine magnetic field, the isomer shift values and the volume fraction of martensite decrease with increasing Si content.
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    Mossbauer studies on athermal martensite formation in an Fe-Ni-Mn alloy
    (Indian Academy Sciences, 2002) Aydin, A.; Güler, E.; Aktas, H.; Gungunes, H.
    In this study, austenite-martensite phase transformations which are formed by cooling effect in Fe-30% Ni-0.2% Mn alloy are investigated with Mossbauer spectroscopy and scanning electron microscopy. The single peak of the paramagnetic phase and the six peaks of the ferromagnetic phase of Fe-30% Ni-0.2% Mn alloy were observed in the Mossbauer spectrum. The internal magnetic field strength of ferromagnetic martensite phase was. determined as 33.8 T and the isomer shift values were determined as - 0.11 mm(.)sec(-1) and - 0.06 mm.sec(-1), respectively, for the austenite and martensite phases. In this alloy, athermal transformation was observed. The results obtained are in agreement with literature.
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    Some characteristics of thermally induced martensite in Fe-30%Ni-3.6%Mo alloy
    (Elsevier Science Inc, 2008) Yasar, E.; Guler, E.; Gungunes, H.; Durlu, T. N.
    Kinetical, morphological and magnetic characteristics of thermally induced martensite in an Fe-30%Ni-3.6%Mo alloy has been studied by scanning electron microscopy, transmission electron microscopy and Mossbauer spectroscopy. Scanning electron microscope and transmission electron microscope observations revealed the occurrence of both athermal and isothermal martensitic transformation in the alloy. In addition, the magnetic properties of both the austenite and martensite phases were determined by the Mossbauer spectroscopy. The Mossbauer spectra showed a paramagnetic character for the austenite phase and an antiferromagnetic character for the martensite phase. (C) 2007 Elsevier Inc. All rights reserved.