| Abstract Scope |
Some metallic materials possess the capability to revert to their original shape before deformation on exposure to temperature (shape memory effect) or stress (superelastic effect). This is brought about by the reversible phase transformations (austenite to martensite and vice versa). They recover strain as much as 8%. During full cycling, they transform from austenite to martensite, and therefore, the cycling temperatures are between martensite finish (Mf) and austenite finish (Af) temperatures. However, partial cycling occurs before the phase transformation is complete. Consequently, only a limited volume of the phases undergoes phase transformation. Partial cycling is classified into three types based on the operating temperature range and the transformation temperatures of the alloy. This work discusses different types of partial transformation cycling and behaviour of a binary Ni-based alloy during cycling in detail.
Keywords: Partial transformation, Transformation temperatures, Austenite, Martensite, Ni-Ti alloy. |