ICAMS / Interdisciplinary Centre for Advanced Materials Simulation


Effect of Al alloying on the martensitic transformation temperature in Ti-Ta shape memory alloys

Date: 22.03.2017
Place: DPG Spring Meeting, Dresden, Germany

Alberto Ferrari
Jutta Rogal
Ralf Drautz

TiTa-based alloys are promising candidates as high-temperature shape memory alloys (HTSMAs) for actuators and superelastic applications. The shape memory mechanism involves a martensitic transformation between the low-temperature α'' phase (orthorhombic) and the high- temperature β phase (body-centered cubic). In order to prevent the degradation of the shape memory effect, TiTa needs to be alloyed with further elements. However, this often reduces the martensitic temperature Ms , which is usually strongly composition dependent. The aim of this work is to analyze how the addition of a third element to TiTa alloys affects Ms by means of electronic structure calculations. In particular, it will be investigated how alloying Al to TiTa alters the relative stability of the α'' and β phases. This understanding will help to identify new alloy compositions featuring both a stable shape memory effect and elevated transformation temperatures.

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