Novel Thermographic Method for Characterizing Transformation Temperatures of Thin-Film Shape Memory Alloys Aimed at Combinatorial Approach

作者：Aono Yuko^*; Sakurai Junpei; Shimokohbe Akira; Hata Seiichi

来源：Japanese Journal of Applied Physics, 2011, 50(6): 066601.

DOI：10.1143/JJAP.50.066601

A novel characterization method for the two-way martensitic transformation temperatures of thin-film shape memory alloys (SMAs) is proposed. The method uses thermography to detect the transformation as a change in emissivity. The proposed method was demonstrated for a Ti-Pd-Ni thin-film SMA along with electrical resistivity monitoring. Definite emissivity changes were observed during both heating and cooling. Furthermore, the changes in emissivity corresponded to changes in the electrical resistivity. To confirm the validity of the proposed method, the results were compared with results obtained using conventional differential scanning calorimetry (DSC). The reverse-martensitic transformation temperature was found to agree with the results of the proposed method. However, the martensitic transformation temperature did not agree well. The reason for this disagreement is the differences in the definition of the transformation temperature and stress conditions used. We expect that the proposed method will enable high-throughput characterization of SMAs by a combinatorial approach in the future.

• 出版日期2011-6