In situ infiltration behavior and interfacial microstructure evolution between Al and carbon fibers

Abstract

The infiltration process of Al into unidirectional carbon fiber (CF) bundles was observed using in situ synchrotron radiation imaging technique. The effects of surface metallization and matrix alloying on the infiltration behavior were studied. The infiltration process of the original Al/CF couple was a physical filling process due to the poor wettability. Thus, the observed infiltration distance presented an approximately linear increase over time. With Ni coatings, the improvement in the wetting behavior changed the infiltration process to spontaneous infiltration, and the average infiltration velocity significantly increased from 0.25 μm/s to 0.72 μm/s. The spontaneous infiltration behavior was further improved by stronger Al-Mg-Ni reaction during matrix alloying, and the velocity increased to 0.91 μm/s. For the CF reinforced Al-matrix composites fabricated by a rolling method, an improved infiltrated microstructure with few defects was obtained under surface metallization and matrix alloying due to the multi-element interfacial reaction.