Microstructure and Fluidity Evolution of Recycled Materials of Al-B_4C Metal Matrix Composites

摘要

Remelting is a promising method to recycle process scraps of Al-B_4C metal matrix composites generated during the casting and transformation processes. Fluidity evolution of remelt scraps from cast billets and extruded plates was investigated by means of vacuum fluidity tests. The results showed that the fluidity decline of cast materials was much faster than that of the extruded materials. In order to understand the flow behavior and recyclability of different composites, the microstructure of process scrap materials and fluidity samples after remelting was examined. The distribution of B_4C particles and its reaction products, as well as the effective volume fraction in the scrap materials and fluidity samples, were quantitatively characterized by an image analyzer under optical microscopy. It was found that the fluidity of the extruded materials, hence its recyclability, is better than that of cast materials in the remelting process due to more uniform particle distribution and less particle agglomerates.