Microcalorimetry on metastable beta phase alloys subjected to applied stress

The development of a High Sensitivity Scanning Stress Microcalorimeter for the study of martensitic phase transformations in beta phase CuAlNi single crystal tensile specimens is described. The design of this system is discussed with reference to an earlier version. The values of calorimetric sensitivity reported for the new system represent a significant improvement over the prototype and a comparison is made. More significantly, the new sensitivity values compare directly with those reported for stress free instruments employing similar detectors indicating that many of the problems associated with calorimetric measurements under stress have been considerably reduced. (orig.)