Hot explosive compaction of aluminum-nickelide composites

Two series of nickel-coated aluminum (Al−Ni) powder compositions were consolidated to full or near-full density by a hot-explosive-compaction (HEC) technique. Mixtures of 78Al-22Ni at. pct (63Al-37Ni wt pct) or 39Al-61Ni at. pct (23Al-77Ni wt pct) were placed in cylindrical containers, preheated to a range of temperatures from ambient to 1000°C, and once at a uniform temperature, explosively compacted into a 150-mm-long and 15-mm-diameter rod-shaped billet using a cylindrical detonation arrangement. The resultant billets were sectioned and prepared for examination by optical microscopy and scanning electron microscopy (SEM). Energy-dispersive X-ray spectroscopy (EDS), X-ray diffraction (XRD), and microhardness measurements were used to characterize the billet morphology, structure, and chemical composition. Analysis revealed that depending on the preheating temperature, the initial Al−Ni composition transformed into several aluminum nickelide (Al−Ni) intermetallics. The onset and nature of the shock-induced transformation from the precursors into the products are discussed.