1. Classification y Ideal or perfect crystal real or defect crystal According to dimension o point defect: vacancies, interstitial atoms s line defect dislocation planar defect: stacking fault o volume defect mosaic structure
6. 8 Diffusion Mechani sm Flick's' law in microscopic form 1. One dimensional diffusion. jump frequency period probability of atom jumping to nearest position
Discrepancies between theory and practice in Deformation. 1. Morphology of the surface in deformation. 2. The great difference between theoretical and actual strength of single crystals (. >>)
Introduction 1. Definition: Fis a fictitious force which is supposed to be responsible for the motion of dislocation. Fll Criterion: The work done on crystal by stress must be equal to that done on dislocation by force F. 2. Principle of derivation of F: Macroscopic work=microscopic work (or deformation work)