Characterization of Al2 O3 Matrix Composites Fabricated via the Slip Casting Method Using NiAl-Al2 O3 Composite Powder

Abstract

This work aimed to characterize Al2 O3 matrix composites fabricated by the slip casting method using NiAl-Al2 O3 composite powder as the initial powder. The composite powder, consisting of NiAl + 30 wt.% Al2 O3, was obtained by mechanical alloying of Al2 O3, Al, and Ni powders. The composite powder was added to the Al2 O3 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 NiAl2 O4 spinel phase. Finally, the phase composition of the composites changed from the initial phases of Al2 O3 and NiAl to Al2 O3, Ni, and NiAl2 O4 . However, in the area of Ni, fine Al2 O3 particles remaining from the initial composite powder were visible. It can be concluded that after slip casting, after starting with Al2 O3 and the composite powder (NiAl-Al2 O3 ) and upon sintering in air, ceramic matrix composites with Ni and NiAl2 O4 phases, complex structures, high-quality sintered samples, and favorable mechanical properties were obtained.