In materials science, a grain boundary is the interface between two grains, or crystallites, in a polycrystalline material. Grain boundaries are two-dimensional defects in the crystal structure, and tend to decrease the electrical and thermal conductivity of the material. Most grain boundaries are preferred sites for the onset of corrosion[1] and for the precipitation of new phases from the solid. They are also important to many of the mechanisms of creep.[2] On the other hand, grain boundaries disrupt the motion of dislocations through a material, so reducing crystallite size is a common way to improve mechanical strength, as described by the Hall–Petch relationship.
- ^ Lehockey, E.M.; Palumbo, G.; Lin, P.; Brennenstuhl, A.M. (May 1997). "On the relationship between grain boundary character distribution and intergranular corrosion". Scripta Materialia. 36 (10): 1211–1218. doi:10.1016/S1359-6462(97)00018-3.
- ^ Raj, R.; Ashby, M. F. (April 1971). "On grain boundary sliding and diffusional creep". Metallurgical Transactions. 2 (4): 1113–1127. Bibcode:1971MT......2.1113R. doi:10.1007/BF02664244.