Dresden 2006 – wissenschaftliches Programm
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MM: Metall- und Materialphysik
MM 25: Poster Session
MM 25.34: Poster
Mittwoch, 29. März 2006, 15:30–17:30, P4
Drift and fluctuation of MS during thermal cycling of Ni63Al37 — •Leonard Müller, Benno Ludwig, and Uwe Klemradt — II. Physikalisches Institut, RWTH Aachen University
Measurement of time dependent phenomena in athermal martensite were conducted in a dedicated temperature chamber with an excellent temperature stability of ± 4 mK over at least 63 hours. The phase transformation was observed in-situ by laserlight reflection and optical imaging.
The MS temperature of an athermal martensite is classically considered to be a constant for each material system after some training. Results are presented that clearly show a trend in MS and in addition a strong fluctuation of Δ MS=±4 K around this trend occuring during 125 thermal cycles. The reverse transformation shows the same behaviour. Statistical data analysis shows a non-normal distribution of MS. Evidently, the thermal history is an important factor which can influence MS and incubation times as well. Optical imaging shows microfractures in the sample that open in the martensitic phase, which probably affect the observed changes of MS.