Structural instability and damping properties of heterophase materials based on aluminium alloys

Abstract

The method of internal friction (IF) has been used for studying the structural instability of aluminium alloys strengthened with boron and carbon fibers, silicon carbide whisker crystals, and silicon particles taken in the volume concentrations 45%, 50%, 20%, and 30%, respectively. The effects discovered in elastic and nonelastic properties of composite materials (CM) at various temperatures, amplitudes, and kinds of deformation have been used as the basis for analyzing some aspects of physical and physicochemical compatibility of components in CM. These include variations of residual thermal stresses in the matrix at thermocycling, their relaxation, the state of phase boundaries, the kinetics of solid-phase physicochemical interaction of components, etc. The physical mechanisms of oscillation damping in heterophase materials are considered and an analysis is made of the temperature relationship for IF in fibrous composite materials (FCM) according to the data on elasticity and nonelasticity of their components.