Transforming Materials

Shape memory and superelastic alloys represent a unique class of functional materials capable of recovering large strains through stress- or temperature-induced martensitic phase transformations. These materials offer significant potential for aerospace, biomedical, and actuator applications where conventional alloys cannot meet the demanding requirements for both structural integrity and functional response. However, the complexity of these transformations and their interaction with applied and residual stress presents significant challenges for reliable design.

The group has an extensive research programme on NiTi-based shape memory alloys, with a focus on understanding and controlling transformation temperatures and thermal hysteresis through compositional modification and thermomechanical processing. By tailoring alloy chemistry and processing routes, we seek to develop materials with precisely defined functional responses for targeted applications. This work draws on a range of characterisation techniques including synchrotron X-ray diffraction, differential scanning calorimetry, and in-situ mechanical testing to probe the underlying transformation mechanisms in detail.

For applications where nickel sensitivity is a concern, the group also investigates Ni-free alternatives based on beta-titanium alloy systems. Research in this area focuses on understanding the precipitation behaviour and phase characteristics of these alloys, and how these microstructural features govern functional fatigue and long-term stability. Synchrotron diffraction plays a central role in this work, enabling the phase transformations and their evolution under load to be characterised with high precision.