INTERFACIAL CONTRIBUTION TO MECHANICAL-PROPERTIES OF MULTILAYER MATERIALS

Multilayer materials are model systems for investigating how interfaces determine the mechanical properties of composite materials. Some multilayer materials exhibit a supermodulus effect where certain elastic moduli are enhanced by factors of three or more at critical values of layer thickness. Recent investigations have demonstrated that the enhancements in the biaxial and Young's modulus in the best superlattice materials appear to be much smaller than in the original samples studied a decade ago. The shear modulus usually shows a softening. Computer simulation studies indicate that lattice distortions at coherent (epitaxial) interfaces play a significant role. Even more important is interfacial atomic disorder. © 1990.