Fects of the pre-strain on the kinetics and volume fraction of martensitic phase transformations in an Fe-30% Ni-3% Pd alloy
Özet
In this study, kinetics, morphological and magnetic properties of thermal induced and pre-strain of austenite martensitic transformations in an Fe-30%Ni-3%Pd alloy were investigated. Effect of pre-strain to austenite phase above the Ms temperature and kinetics, morphological and magnetic properties of martensitic transformations which was formed by below the Ms temperature after the pre-strain were investigated. Kinetics of martensitic transformation (martensite start temperature (Ms), austenite start temperature (As) and austenite finish temperature (Af)) were determined by Diferential Scanning Calorimetry (DSC). Kinetics of the transformation was found to be as athermal type and Ms temperature decreased with increasing prestrain. 5% and 10% pre-strain which was applied to austenite phase at room temperature formed slip lines. Martensite plates, which were broken and bent, formed by cooling the alloy after 5% prestrain and martensite plates which were decrescent formed by cooling after 10% pre-strain, observed by Scanning Electron Microscopy (SEM). The volume fraction of martensite and austenite phases, the hyperfine magnetic field of martensite phase and isomery shift values in Fe-30%Ni-3%Pd alloy have been determined by using Mössbauer Spectroscopy. The pre-strain which are influential on the transformation kinetics and the martensite plates morphology, increased the rate of martensite volume. © IDOSI Publications, 2013.
