Sie befinden Sich nicht im Netzwerk der Universität Paderborn. Der Zugriff auf elektronische Ressourcen ist gegebenenfalls nur via VPN oder Shibboleth (DFN-AAI) möglich. mehr Informationen...
Direct observation of the NiTi martensitic phase transformation in nanoscale volumes
Ist Teil von
Acta materialia, 2010, Vol.58 (2), p.490-498
Ort / Verlag
Kidlington: Elsevier Ltd
Erscheinungsjahr
2010
Link zum Volltext
Quelle
Alma/SFX Local Collection
Beschreibungen/Notizen
We report on quantitative in situ transmission electron microscopy nanocompression tests used to study the deformation behavior of NiTi pillars on the nanometer scale. By recording the diffraction patterns in real time we have obtained direct evidence that the stress-induced B2 to B19′ (austenite to martensite) transformation exists in NiTi even when the sample size is below 200
nm. Correlation of the appearance of the B19′ phase in the diffraction pattern with our quantitative data showed that the transformation starts at approximately 1
GPa. We found that the transformation occurred through a multi-step process, and that the reverse transformation did not occur due to extensive deformation of the B19′ phase. Our results have direct implications for the application of the shape memory effect in nanoscale NiTi devices.