Characterization of TiN-AlN composites prepared through mechanical alloying and followed by pressure sintering

The ceramic composites consisting of titanium nitride and aluminium nitride were prepared by mechanical alloying (MA) of AlN, Ti and ammonium carbonate. Comparing with conventional way, which used AlN and TiN powders as the initial materials, in this study, nearly full densification can be achieved by hot pressing or by spark plasma sintering at much lower temperatures. XRD analysis indicated that besides AlN and TiN, Al₂O₃ is also present after sintering. SEM observations showed that the average grain size of the sintered compacts is lower than 0.5 μm. The sample which had been subjected to MA using steel grinding medium for 52 h exhibited Vickers hardness of 18.9 GPa, which is comparable to the value that reported by other researchers.