Production of Alumina Matrix Nanocomposites with Inclusions of TiC and TiB2, via Reactive Milling

• Published in: Key engineering materials 2001-01, Vol.189-191, p.208-215
• Main Authors: Contardi, O.A., Pallone, Elíria Maria Jesus Agnolon, Chinelatto, Adriana Scoton Antonio, Tomasi, Roberto
• Format: Article
• Language: English
• ISSN: 1013-9826; 1662-9795; 1662-9795
• DOI: 10.4028/www.scientific.net/KEM.189-191.208

We describe the production of alumina matrix nanocomposites with inclusions of TiC and TiB2, using, as precursors, mixtures of nanometric powders prepared by reactive milling. The reactive milling was performed in a high-energy mill SPEX Mixer/Mill 8000, through the reactions: 4Al + 3C + 3TiO2 and TiO2 + B2O3 + 10/3Al, producing alumina with TiC and TiB2, respectively. The reaction products were formed as strong agglomerates of nanometric particles and conventional ball milling performed the deagglomeration. The dispersed powders were characterized by XRD and DSC. The reaction products were mixed with a commercial alumina (Sumitomo AKP-53) to produce final composites with 5 and 10 wt pct of inclusions by ball milling in ethyl alcohol. The alcohol suspensions were dried by heating at 70 C. The powder mixtures were pressed and sintered at 1500 C and 1600 C in a high-vacuum atmosphere for 1 h. The sintered samples reached a final relative density of 95-97 percent TD, and the high resolution SEM microstructure analysis has shown the dispersion of the inclusions with a few remaining agglomerates from the synthesis process. (Author)