Effect of recycled TiC addition in the compaction and sintering behavior of Al-Mg-Cu-Zn + r-TiC powder metallurgy composites

Abstract

The radical increase in daily use of metal matrix composites with ceramic reinforcements tangibly increases scrap, which contains valuable ceramic materials. As hard ceramic materials are cost-intensive, there is a significant necessity for their recovery and recycling at all times. This work attempts to recover valuable titanium carbide particles from a scrap of in-situ synthesized AA7075-TiC composites for reuse as reinforcements. The TiC particles were recovered by the corrosive chemical extraction method and analyzed for morphologies, such as shape, phase, and size using scanning electron microscopy, x-ray diffraction, and dynamic light scattering techniques. Further, Al-Mg-Cu-Zn powder was blended with various percentages of the recovered TiC particles to investigate the characteristics of the blends. The compressibility behavior of various blends is correlated with linear and non-linear models, which identified that the Kawakita and modified Cooper-Eaton models showed better fitness in the experimental results, which also explained the mechanisms of compressibility behavior. The extent of the effective percentage addition of recovered TiC as reinforcement in the Al-Mg-Cu-Zn alloy was identified based on the green strength obtained using the diametrical compression test. The best suitable sintering temperature was also determined using thermogravimetric analysis or differential scanning calorimetry and the estimated sinterability index.