Non-isothermal grain growth in metals and alloys

A large portion of the previous research on grain growth has been focused on isothermal conditions and excellent reviews on this topic are available in the literature. However, most of the materials processing operations such as casting, rolling and welding take place under non-isothermal conditions. Grain growth in materials under significant spatial and temporal variation of temperature exhibits many important special characteristics. The present paper critically examines these special features of grain growth in several important materials processing operations. Various experimental and theoretical approaches used to study grain growth in non-isothermal systems are examined and compared. The classical isothermal grain growth theories are reviewed, because they are sometimes applied to non-isothermal systems by incorporating thermal history in the calculations. Various numerical techniques and their applications to non-isothermal systems are also examined and compared. Finally, progress made in understanding non-isothermal grain growth in metals and alloys is summarised and several areas of future research are identified. This review is targeted towards an audience of materials scientists and engineers interested in various materials processing operations under non-isothermal conditions.