Definition - What does Crystallites mean?
Crystallites are tiny (usually microscopic) crystals that are bonded together by boundaries that are highly irregular, comprising polycrystalline solids.
Crystallite boundaries should be examined for weak bonding, as these are the most likely sites for corrosion onset, since grain boundaries can cause interruption and dislocation motions in materials.
Crystallites are also known as grains.
Corrosionpedia explains Crystallites
Metals can contain crystallites which can be fractured at their boundaries. When the boundaries are subjected to attack by various crystallites, intergranular corrosion occurs. Hence, intervention such as refinement and solidification of grains should be employed to prevent damages that may be brought on by corrosion.
The migration of crystallite boundaries plays a significant role in the creep mechanism. The migration of crystallite boundary takes place when shear stress reacts on the plane of grain boundaries, making the crystallites move or slide. Fine-grained crystallites have low resistance to corrosion damage or creep due to the fact that tinier grains have a higher number of atoms present in grain boundary areas.
Crystallite boundaries can lead to deformation or may become a source of defects. Voids can form in crystallite boundaries, and when this occurs to a significant extent, the structure may suffer damage or fracture.
Technological innovations have lessened the effects of crystallites boundaries. The end result is a solidification technique wherein the grain boundaries are removed through the production of columnar grains that are aligned parallel to the material's axis.