| Popis: |
The thermal expansion of simple solids arises from anharmonic vibrations of their atoms and is resisted by the forces bonding the atoms together. Although neutron scattering studies have permitted the derivation of some anharmonic terms in the potential energy function, the accuracy of predicted coefficients of thermal expansion seldom suffices for the understanding of thermal behavior even in simple solids, and cannot yet be applied to complex or heterogeneous ones. The authors, recognizing that CTE values are deserving of equally precise treatment with the critical properties of elastic modulus, thermal stability, and strength, have made a modest beginning toward interrelating all of these in simple solids and in structural composites. The former are here treated as packings of spherical atoms characterized by their “atomic density” values and by their measurable deviations from ideal packing. On a larger scale, a method for predicting the CTE of structural composites through the Law of Mixtures has been tested adequately to suggest that this important property can be tailored within wide limits to structural requirements. |
