Materials Science World Congress

These materials are determined by the grain size on a nanometer scale, usually less than 100 nanometers, and impart unique physical and chemical properties compared with coarse-grained counterparts. Such microstructure of nanocrystalline materials gives them improved mechanical strength and hardness and superior wear resistance, making nanocrystalline material candidates for virtually all applications under research in materials science and engineering.

The most important and striking property of nanocrystalline materials is the increase in strength. Due to the Hall-Petch effect, a smaller grain size increases the yield strength of the material. This feature has attained especially significant importance in applications where high strength-to-weight ratios are often required, like aerospace or automobile components. Nanocrystalline materials usually show improvement in ductility and toughness, meaning they will stand against stress without fracturing.

Nanocrystalline materials have both thermal and electronic behavior that is inconsistent with the corresponding properties of their bulk counterpart. Despite showing improved thermal stability, they could depict better electrical conductivity and therefore can be applied in the electronics field, such as for conductive coatings and semiconductor devices, among others. Small grain size also enables additional diffusion processes that may find application in catalysis and energy storage technologies.

Nanocrystalline materials are synthesized through many routes. This includes solid-state processing, chemical vapor deposition, and sol-gel techniques. The synthesis method is known to strongly influence the material properties obtained, so such processes tailored to applications are required.