Defect-induced dynamic pattern formation in metals and alloys

Publisher This chapter focuses on “spontaneous pattern formation” in solids driven far from equilibrium, involving explicitly the role of structural defects. There is an energetic cost associated with pattern formation that involves a multiplication of interfaces. Solids can be either prepared out of equilibrium, or maintained out of equilibrium by a continuous injection of energy from outside the system. Both cases are possible for metallic alloys, and both lead to pattern formation. Maintaining a system out of equilibrium can be accomplished either by plastic deformation or by irradiation. In metallic alloys, pattern formation in space can be manifested in two ways: it can be a patterning of phases of different chemical composition, such as in the decomposition of solid solutions, or it can be a patterning of the structural defects themselves as in the case of plastically deformed materials. Special circumstances can observe an equivalent in the plastic behavior of materials— “serrated yielding.”