Characterization of Al 2 O 3 Matrix Composites Fabricated via the Slip Casting Method Using NiAl-Al 2 O 3 Composite Powder.

This work aimed to characterize Al 2 O 3 matrix composites fabricated by the slip casting method using NiAl-Al 2 O 3 composite powder as the initial powder. The composite powder, consisting of NiAl + 30 wt.% Al 2 O 3 , was obtained by mechanical alloying of Al 2 O 3 , Al, and Ni powders. The composite powder was added to the Al 2 O 3 powder to prepare the final powder for the slip casting method. The stained composite samples presented high density. EDX and XRD analyses showed that the sintering process of the samples in an air atmosphere caused the formation of the NiAl 2 O 4 spinel phase. Finally, the phase composition of the composites changed from the initial phases of Al 2 O 3 and NiAl to Al 2 O 3 , Ni, and NiAl 2 O 4 . However, in the area of Ni, fine Al 2 O 3 particles remaining from the initial composite powder were visible. It can be concluded that after slip casting, after starting with Al 2 O 3 and the composite powder (NiAl-Al 2 O 3 ) and upon sintering in air, ceramic matrix composites with Ni and NiAl 2 O 4 phases, complex structures, high-quality sintered samples, and favorable mechanical properties were obtained.