Martensitic transformations in [001] CuAlZnMn single crystals

Superelastic behavior of a metamagnetic Ni–Mn–Sn single crystal

“…At this point, it is also worth reemphasizing that the currently observed stabilization effect primarily affecting the A s temperature but having essentially no influence on the A f temperature, which is reproducible on the first and second heating runs, somewhat differs from the more traditionally reported stabilization phenomena [23][24][25][26][27]. Typically the mechanical stabilization effect [23][24][25][26][27] refers to the shift in A s well above the A f of the destabilized state, unlike here. It thus corroborates that the mechanical modification of microstructure toward a two-or a single-variant state leading to a shift in the A s temperature is linked to the release of the elastic strain energy stored in the multivariant state what then necessitates greater overheating to initiate retransformation and contributes to the shift in A s .…”

“…It then implies that the shift in the A s temperature in the trained samples should be chiefly associated with lower surface energy entailing larger and less mobile phase interface and thus a greater energy barrier for austenite restoration [29,31]. At this point, it is also worth reemphasizing that the currently observed stabilization effect primarily affecting the A s temperature but having essentially no influence on the A f temperature, which is reproducible on the first and second heating runs, somewhat differs from the more traditionally reported stabilization phenomena [23][24][25][26][27]. Typically the mechanical stabilization effect [23][24][25][26][27] refers to the shift in A s well above the A f of the destabilized state, unlike here.…”

“…The A s temperatures then assume lower values during the second heating experiment once the specimen has recovered the multivariant microstructure following the first heating experiment. The change in the A s temperature between the first and second cycles, i.e, between the two-variant and/or a singlevariant state and a multivariant condition is circa DA s = 29 K. This effect may be understood in relation to the stress-induced stabilization of martensite [23][24][25][26][27], where in principle large lattice mismatch between the austenite and single-variant martensite upon reverse MPT requires a formation of twinned martensite plates at the interface region to accommodate local incompatibility between the parent and martensitic phases. As a result, thermally induced twinning stands in need of a more substantial overheating shifting the A s to a higher temperature range.…”

Martensitic transformations of Cu-Al-Ni single crystals in tension/compression

“…The general method of the construction of the c-T diagram from thermomechanical test data can be found in Ref. [7]. …”

“…The actual choice of the transformation path [5] depends on the magnitude of stress, temperature, orientation of the load axis and on the sense of load. It is helpful to identify regions of existence (a, T conditions at which given solid phase may exist) and regions of stability (a, T conditions at which given solid phase exists regardless of history) of all individual phases in the diagram [7]. In the CT-T diagram in Fig.…”