THE POTENTIAL ENGINEERING OF GRAIN-BOUNDARIES THROUGH THERMOMECHANICAL PROCESSING

Grain boundary character distribution is a relatively new microstructu ral feature that describes the proportions of random and special grain boundaries as defined by the coincident site lattice model. The combi nation of the availability of a new experimental technique based on th e automatic indexing of backscatter Kikuchi electron diffraction patte rns in the scanning electron microscope (orientation imaging microscop y) and reports in the literature describing the optimization of the gr ain boundary character distribution through thermomechanical processin g are making the potential for enhanced materials properties in commer cial metals and alloys a reality. Although the effects of optimizing t he grain boundary character distribution in the cost-effective improve ment of properties have been documented, the potential for commerciali zation has limited the disclosure of processing details. In this artic le, two separate approaches to the optimization of the grain boundary character distribution in oxygen-free electron copper at Lawrence Live rmore National Laboratory are discussed.