Residual Stress Measurements on Aluminum-Graphite Composites Using X-Ray Diffraction Techniques

摘要

Metal Matrix Composites (MMCs) have generated considerable interest in the materials field, because of their potential applications in dynamic structures. A MMC with its excellent mechanical as well as physical properties carries a distinct advantage over other composite systems, particulary at high temperatures. At the same time a MMC system is characterized by heterogeneity, anisotropy and interfaces which affect those properties considerably. Interfaces have been known to influence the properties of MMCs significantly and their importance has been discussed extensively. However, the interface chemistry and its exact role in alteration of various properties is not well-known yet. One of the important things needed for better understanding of the interface is its stress state. Thermal and mechanical treatments involved in the fabrication of composite materials, give rise to triaxial residual stresses. Speculations are that these stresses, originating from the differing thermal coefficients of the reinforcement and the matrix, play an important part in the transverse properties of the MMCs.