Two 5 vol% Ni/Al 2 O 3 composites with the difference in Al 2 O 3 grain size were fabricated by pulsed electric current sintering technique to investigate the influence of Al 2 O 3 grain size on oxidation behavior of the composites. Average Al 2 O 3 grain sizes of two fabricated composites were 1.1 μm and 0.5 μm after sintering. Oxidation tests were conducted at temperatures ranging from 1100 to 1350 °C for 1-48 h in air. A thin NiAl 2 O 4 layer was observed in exposed surface of samples after oxidation. An oxidized zone that consisted of Al 2 O 3 matrix and NiAl 2 O 4 grains was defined. Growth of the oxidized zone obeyed the parabolic law. Influences of Al 2 O 3 grain size on high-temperature oxidation of the composites were discussed.
ASJC Scopus subject areas
- Ceramics and Composites