Abstract
The use of high resolution automatised equipment (HRTA, conduction calorimetry, stress-strain-temperature) allows to study, locally and/or globally, the martensitic transformations of the alloys with memory (Cu-Zn-Al). The observations allow to establish the phenomenology of the effects of the cycling on the crystalline structure. Particularly, the formation of defects, the interactions between the interphases and the precipitates that change the relative stability of the phases, the effects of the nucleation and the growth. The experimental research of the area of coexistence of the two phases allows to set a phenomenological model coherent with the experimental observations.
Zusammenfassung
Unter Anwendung einer hochauflösenden automatisierten Apparatur (HRTA, Leitfähigkeitskalorimetrie, Zug-Dehnungstemperatur) können sowohl lokal als auch global die martensitischen Umwandlungen von Legierungen mit Erinnerungsvermögen (Cu-Zn-Al) untersucht werden. Die Beobachtungen gestatten die Feststellung der Phänomenologie des Einflusses von periodischen Schwankungen auf die Kristallstruktur, insbesondere Fehlstellenbildung, Wechselwirkungen zwischen Zwischen-phasen und Fällungen, die die relative Stabilität der Phasen verändern sowie der Einfluß von Keimbildung und Keimwachstum. Die experimentelle Ergründung der Gebiete mit zwei koexistenten Phasen erlaubt die Schaffung eines phänomenologischen Modelles, welches mit den experimentellen Beobachtungen übereinstimmt.
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The financial aid from CICYT (project MAT89 - 0407 - CO3) is gratefully acknowledged. F.C.L. acknowledges the DGICYT (sabatic program) and the EEC (third countries program) for financial aid in the stay at Spain.
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Amengual, A., Isalgué, A., Lovey, F.C. et al. Shape memory alloys: Local and global transformations by high resolution thermal analysis. Journal of Thermal Analysis 38, 593–602 (1992). https://doi.org/10.1007/BF01979386
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DOI: https://doi.org/10.1007/BF01979386