The densification behaviors of Al2O3-Cr 2O3/Cr3C2 nanocomposites prepared by a Spark Plasma Sintering (SPS) were investigated in this work. The initial powders used for sintering were Al2O3-Cr2O 3, which were prepared by metal organic chemical vapor deposition (MOCVD) in a spout bed. Different colors of the compacts such as green, purple and black were observed after densification process at different SPS temperatures from 1200 °C to 1350 °C. These changes of color were relevant to the existence of secondary phase of green Cr2O 3, pink solid solution of Cr2O3-Al 2O3 and black Cr3C2, which were formed under the different SPS temperature. The secondary phase of Cr 2O3 retarded the processing of densification for spark plasma sintering at 1200 °C. The Cr2O3 reacted with Al2O3 to form solid solution of Cr2O 3-Al2O3 and with carbon to form Cr 3C2 as sintering temperature increased to 1350 °C. The characteristics of high heating rate, shorter sintering time for SPS and the formation of secondary phase of Cr3C2 effectively reduced the substrate's grain growth, making Al2O3-Cr 2O3/Cr3C2 nanocomposites with small grain size.
All Science Journal Classification (ASJC) codes
- Electronic, Optical and Magnetic Materials
- Ceramics and Composites
- Process Chemistry and Technology
- Surfaces, Coatings and Films
- Materials Chemistry