Fabrication of bulk AlN–TiN nanocomposite by reactive ball milling and underwater shock consolidation technique

Reactive milling of aluminum nitride and titanium powders corresponding to the stoichiometric reaction Ti + AlN resulted in the formation of the ceramic matrix composite AlN–TiN. Prolongation of the milling process led to a microstructure with nanosize range of crystallites of both AlN and TiN, evidenced through XRD measurements, SEM and TEM observation. Further, underwater shock compaction with a pressure level of about 10 GPa was applied to the nanocomposite powders to obtain bulk nanostructured sample. The effect of this shock compaction on the prolonged milled powder resulted in a 22% reduction in crystallite size. The average microhardness of the consolidated nanocomposite was 656 HV and 840 HV for 40 h and 100 h MA samples, respectively, with densities 98% of theoretical values in both cases as well as no change in chemical composition.