Abstract
On the basis of recent knowledge of structure-dependent boundary properties, the design and control of boundary-related bulk properties and performance of advanced polycrystalline materials are discussed. The grain boundary character distribution (GBCD) which has been recently introduced as a new microstructural factor is shown to be a powerful tool for designing and controlling the bulk properties in polycrystalline materials. The relationship between texture and GBCD has been discussed in connection with other microstructural factors associated with grain boundaries. It has been shown that the relationship between texture and GBCD can provide an important clue to the grain boundary design and control for polycrystalline materials with desirable properties and performance. The present paper shows recent successful achievement of toughening of brittle materials by controlling texture and GBCD. The potential and prospective of the grain boundary design and control for functional materials are also discussed.