This book offers a comprehensive overview of the microstructures of Ti‑Ni‑based shape memory alloys. It begins by outlining essential specimen preparation and observation techniques for microstructural analysis, drawing on the authors’ experience and unpublished data. Using these approaches, the book presents key observations of twin morphologies and interfacial structures, explains the rational but complex self‑accommodation architecture, and discusses transformation‑induced dislocations. The microstructures of practical alloys, shaped by processing and heat treatment, are also described in detail. In situ SEM studies further illustrate the nucleation and growth of monoclinic and trigonal martensites, the formation of self‑accommodation structures, and the multistage transformation sequence characteristic of aged Ni‑rich alloys. The final two chapters address hydrogen effects relevant to medical applications and, separately, examine nonmetallic inclusions that influence device durability. This book serves students, materials scientists, and engineers engaged in research and development of Ti‑Ni‑based and other shape memory alloys.

Tomonari Inamura is Professor of Institute of Integrated Research, Institute of Science Tokyo, Japan. He graduated with a B. Science. from Tokyo Metropolitan University, Japan, followed by a M. Eng. and a D. Eng. at Tokyo Institute of Technology, Japan. His research concerns the microstructures formed by phase transformations and plastic deformation in alloys. He is the author or coauthor of more than 180 research papers on the subjects.

Minoru Nishida is formerly Professor of Department of Advanced Materials Science and Engineering and now Professor Emeritus at Kyushu University, Japan. He graduated with a B. Eng. from Kumamoto University, Japan, followed by a M. Eng. and a D. Eng at Tohoku University, Japan. His research concerns the solid-state transformations in metals and alloys, particularly the microstructure analysis of shape memory alloys. He is the author or coauthor of more than 230 research papers on the subject.