Ceramic matrix composites in the alumina/5–30 vol.% YAG system

• Published in: Journal of the European Ceramic Society Vol. 31; no. 10; pp. 1889 - 1895
• Main Authors: Lach, R., Haberko, K., Bućko, M.M., Szumera, M., Grabowski, G.
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01-01-2011
• Subjects: Alumina; Aluminum oxide; Ceramic matrix composites; Fracture toughness; Hardness; Heat treatment; Inclusions; Particulate composites; YAG; Yttrium oxide; Alumina; Ceramic matrix composites; YAG
• ISSN: 0955-2219; 1873-619X
• DOI: 10.1016/j.jeurceramsoc.2011.04.003

The preparation technique of the particulate composite materials in the alumina/YAG system was elaborated. Within alumina particles suspension yttria precursor was precipitated with ammonium carbonate. Drying and calcination at 600
°C resulted in the mixture of alumina and yttria particles, the latter being much finer than alumina particles. This mixture was additionally homogenized by short attrition milling in an aqueous suspension. Sintering of such powders results in the materials composed of YAG inclusions of sizes smaller than shown by alumina grains and evenly distributed within the matrix. YAG particles result from the reaction of Y
2O
3 with Al
2O
3 during heat treatment. YAG inclusions limit effectively grain growth of the alumina matrix. Hardness, fracture toughness, strength, Young modulus and wear susceptibility of composites and pure alumina were measured. Composites show higher hardness and in some cases higher fracture toughness and wear resistance than pure alumina polycrystals.