A New Approach to Estimate Heat Variations During A Thermal Induced Phase Transformation On A NiTi SMA

Positive or negative heat variations during a thermal induced phase transformation on a NiTi SMA are generally obtained from DSC. However, using (i) infrared thermal field measurements, (ii) 2D heat diffusion equation, and (iii) image processing, it is possible to get heat source fields associated with the transformations. Already applied to study localized stress induced phase transformations during tensile tests, we propose to use this method to estimate local heat during a thermal induced transformation. An original experimental setup is achieved in order to load and observe the transformations in uniform (0D) or non uniform (1D) configurations. After data processing, heat evolutions measured in 0D and 1D, are finally compared with reference DSC.