Local and depth resolved photothermal characterization of NiTi shape memory alloys

Photothermal methods based on IR radiometry, photopyroelectric detection an d thermoreflectance have been applied to NiTi shape memory alloys to charac terize the thermal properties of the as-prepared samples and to determine t he changes of the thermal properties induced by thermal and mechanical trea tment and cycling. Using photopyroelectric detection, the integral diffusiv ity of the treated and non treated samples has been determined. Depth profi les of the thermal properties of the mechanically and thermally cycled ribb on samples were measured using photothermal radiometry. A photothermal micr oscope based on thermoreflectance was applied to monitor the thermal proper ties across the ribbon edge and to image the thermal and optical variations inside a grove which had been milled into a NiTi shape memory specimen.