Shape Memory Alloys (SMAs) have attractive thermo-mechanical properties, which open new ways for engineering applications such as sensors and actuators. The fundamentals behind these properties are phase transformations. A solid understanding of the structure and microstructure evolution during these phase transformations is vital to the application and development of SMAs. Ti-Ni alloys are the most popular SMAs and gain the most interests from researchers and engineers. This book will help you to develop knowledge on Ni-Ti SMAs.