NiTi-based shape memory alloys beyond the shape memory effect and superelasticity

This thesis presents a research on NiTi-based shape memory alloys beyond the conventional knowledge of physical metallurgy of NiTi-based shape memory alloys. In particular, it is concerned with functionally graded NiTi materials achieved via geometrical graded designs, microstructural thermal stability of NiTi-based matrix in-situ nanowire and nanoribbon composite systems, and theoretical analysis using density functional theory (OFT) of the phase stabilities and transformation pathways of binary near equiatomic NiTi alloy and ternary Ti50Ni50.xCux alloy under hydrostatic compression and shear stresses.