Читать книгу Materials for Biomedical Engineering - Mohamed N. Rahaman - Страница 103

Different planes and directions in crystals can have a different packing of the atoms and, for crystals composed of compounds such as ceramics, they can also have a different composition of atoms or ions. Differences in atomic packing and composition can influence the properties of crystals in different planes and along different directions. Plastic deformation (slip) of metals, as noted earlier, occurs in planes and along directions that have the closest packing of the atoms and not just in any plane or along any direction. Consequently, in correlating properties of materials with their crystal structures, it is often necessary to identify specific atomic positions, planes, and directions in the crystal structure in a succinct manner.