Characterization of Al2O3, Al2O3 + TiO2 powder mixture, and coatings prepared by plasma spraying

• Published in: Materials and manufacturing processes 1997, Vol.12 (5), p.863-875
• Main Authors: RAMACHANDRAN, K, SELVARAJAN, V, ANANTHAPADMANABHAN, P. V, SREEKUMAR, K. P, ANANTHASESHAN, N
• Format: Article
• Language: English
• Subjects: Chemistry; Colloidal state and disperse state; Exact sciences and technology; General and physical chemistry; Powders
• ISSN: 1042-6914; 1532-2475
• DOI: 10.1080/10426919708935190

Al2O3 and its mixture with 3 wt% TiO2 powders were prepared by fusion and crushing methods. Al2O3 + 13 wt% TiO2 and Al2O3 + 40 wt% TiO2 powders were mixtures of fused Al2O3 + 3 wt% TiO2 and 10 wt% and 37 wt% of TiO2 respectively. Chemical analysis of the powders showed that approximately 1 wt% of impurities were present in each powder. True and tap densities were measured and are discussed for all powders. Powder size study showed narrow range of distribution of particle size in each powder. SEM study showed that the particles were in round and other irregular shapes in all the powders. Al2O3 was found to be in alpha phase and TiO2 in rutile phase. All the powders were coated by plasma spraying at 16 kW. The density of the coatings were measured and are discussed. In the coatings, Al2O3 was in both alpha and gamma phases. In Al2O3 + 13 wt% TiO2 and Al2O3 + 40 wt% TiO2 coatings, the oxygen reduction from TiO2 was observed. 12 figs., 2 tabs., 7 refs.