This three-year award supports US-Italy cooperative research on "Linking Deformation Length Scales in Transforming Materials," involving Huseyin Sehitoglu of the University of Illinois-Champaign and Piermaria Davoli of the Milan Polytechnic University (MPU). The presence of slip is a major issue in transforming materials. It limits transformation strains and transformation reversibility. The proposed research will experiment and develop mechanics models to understand how the transformation stress changes with temperature and cyclic loading. In addition, the proposed collaboration will model the detwinning contribution to overall recoverable strains. Finally, the PIs will focus on shear loading to understand the role of stress states on fracture and transformation behavior.
The Milan Polytechnic University has world-class facilities in conducting experiments in multiaxial stress states. Such facilities are expensive to operate, and require first-rate experimentalists. Consequently their capabilities are matched in only a few institutions in the world. There is strong synergy between these capabilities at MPU and that of the PI, who has been involved in cyclic deformation and fatigue focusing on transforming materials. The proposed research is expected to result in information regarding the use of semi-brittle materials in actuators, in sensors, and other engineering applications. It is likely that these materials could be used in space or in bioapplications.
