Superplasticity, the ability of certain materials to undergo very large tensile strains, was first described in 1912. It became the subject of intense research in the early 1960s following a review of Soviet work and the illustration of the potential commercial applications of superplasticity.
There have been enormous advances in the field, of superplasticity since that time. The field has clear commercial applications, but also retains fascinating scientific challenges in understanding the underpinning physical mechanisms. Recent breakthroughs include the development of superplasticity in polycrystalline ceramics, composites and intermetallics, and also the observation of superplasticity in metallic materials at high strain rates. Superplasticity at high strain rates, in particular, is expected to have a significant technological impact on promoting the commercial applications of superplastic materials.
This book emphasizes the materials aspects of superplasticity and thus was written from the materials point of view. A brief history of the development of superplasticity is first introduced. Then, the two major types of superplasticity, i.e. fine-structure and internal-stress superplasticity, and their operative mechanisms are discussed. Other possible superplastic mechanisms, such as Class I solid solutions and superplasticity at dynamic high strain rates are also described. In addition, microstructural factors controlling the ductility and fracture in superplastic materials are presented. The observations of superplasticity in metals (including Al, Mg, Fe, Ti, Ni), ceramics (including monolithics and composites), intermetallics (including Ni-, Ti-, Fe- aluminides), metal-matrix composites (including Al-, Mg- base), and laminates are thoroughly described.