ABSTRACT
This chapter gives an introductory description of the basic physical nature of crystalline materials—crystalline structures and microstructural imperfections including point defects (solute atoms and vacancies), line defects (dislocations), planar defects (grain boundaries and interfacial discontinuities), and volume defects (precipitates and inclusions). The kinetics of dislocation and vacancy movements within the microstructure constitutes various strengthening mechanisms. This provides the physical basis for further discussions on deformation and damage mechanisms in crystalline materials. Despite that the elementary dislocation events occur at the nano-scale, the continuum stress and strain concepts are used to characterize the collective effect of such events as deformation of solid. Also, because of the crystalline nature of such solids, the Stroh formalism of anisotropic elasticity is briefly introduced, in case readers are interested to extend the discussion at the grain structure level.
