Martensitic transformation in heterogenous austenite

The dependence of the martensite structure on the volume fraction of coherent inclusions inherited from aged austenite has been studied. An explanation for the considerable martensite lattice tetragonality in the case of thin martensite twins in comparison with their inclusion diameter is suggested. A reason for surface relief height decreasing for alloys with narrow temperature hysteresis of transformation has been discovered. The aim of this work is to study the structural peculiarities of the narrow hysteresis martensitic transformation in Fe-Ni-Co-Ti allloys that show the characteristic properties of shape memory alloys.