Damage evolution in SiC particle reinforced Al alloy matrix composites by X-ray synchrotron tomography

Abstract

Metal matrix composites (MMCs) have a combination of high strength, high stiffness, and low density. The damage behavior of MMCs has been studied extensively by a combination of traditional mechanical testing, microstructural characterization, and post-experiment fractographic analysis. X-ray tomography is an excellent technique that eliminates destructive cross-sectioning, and allows for superior resolution and image quality with minimal sample preparation. In this work, we have carried out a detailed investigation of the damage behavior of SiC particle reinforced 2080 Al alloy matrix composites by X-ray synchrotron tomography. This work is unique, relative to the existing work in the literature, because it: (a) focuses on a technologically relevant MMC system (2080/SiC p), (b) uses a combination of image analysis techniques to enable visualization and damage characterization, and (c) entails a significant amount of quantitative and statistical analyses of particle fracture and void growth in the composite. A statistically significant number of particles and volume of the composite were characterized, enabling a meaningful and realistic interpretation of the results. Based on this, a detailed understanding of the micromechanisms of fracture and the quantitative influence of particle size and aspect ratio were obtained.