Abstract
It has been shown that ausaged Fe-Ni-Co-Ti alloys exhibit shape-memo- ry effects with a reversible martensitic transformation and a small temperature hyste- resis between the forward and the reverse transformation. This is due to the precipita- tion of small coherent (Ni,c~,Fe)~Ti particles which lead on the one hand to a very ef- fective hardening of the austenite and on the other hand to high elastic back stresses after shearing together with the martensite into a metastable structure. A combined thermomechanical treatment with homogeneously distributed dislocations can favour the homogeneous distribution of the particles. In this case, the obtainable shape memory effect can reach a maximum. Mechanical and thermal properties were studied by means of hardness and dilatometric measurements. The microstructures before and after the martensitic transformation were investigated by optical microscopy. In order to proof the reversibility of the shape memory effect, springs of different dimensions were produced and their behaviour dur- ing the training and under different loads were investigated.
Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
