Separation of matrix alloy and reinforcement from aluminum metal matrix composites scrap by salt flux addition

Separation of matrix alloy and reinforcements from pure Al-SiCp composite scrap by salt flux addi- tion has been theoretically predicted using interface free energies. Experiments performed confirm the theore- tical prediction. Complete separation of matrix aluminum and reinforcement from metal matrix composites (MMCs) scrap has been achieved by addition of 2⋅05 wt% of equimolar mixture of NaCl-KCl salt flux with a metal and particle yield of 84 and 50%, respectively. By adding 5 wt% of NaF to equimolar mixture of NaCl- KCl, metal and particle yield improved to 91 and 73%, respectively. Reusability of both the matrix aluminum and the SiC separated from Al-SiCp scraps has been analysed using XRD, SEM and DTA techniques. The matrix alloy separated from Al-SiCp scraps can be used possibly as a low Si content Al-Si alloy. However, the inter- facial reaction that occurred during the fabrication of the composites had degraded the SiC particles.