Thermodynamics of Twinning

Abstract
The quasiplastic hysteresis occuring in shape memory alloys is associated with twinning in tension and compression, i.e. a conversion of one martensitic variant into another one. It shows the phenomena of internal elasticity and internal yield, heretofore studied extensively in pseudoelasticity, e.g. see [1], [2]. This paper presents experimental evidence of such phenomena and it offers partial explanation in identifying the onset of yield as an instability phenomenon due to coherency. That conjecture is motivated from a previous consideration of pseudoelasticity.