abstract
SiAlON matrix composites were prepared from a precursor reaction mixture of alpha-Si(3)N4, AlN, Al2O3 and Y2O3 powders and reinforced with different proportions of elongated SiAlON particles obtained by combustion synthesis. Green cylindrical specimens were consolidated by slip casting from well dispersed suspensions. The dried samples were densified by hot pressing at 1650 and 1700 degrees C and then characterized for density, phase composition and microstructure. Hardness tests, fracture toughness by indentation and pin on disc wear, were also chosen to characterize their mechanical properties. The effects of the processing variables (sintering temperature, proportion of added rod-like SiAlON particles) on the microstructural features and on the mechanical properties were studied and a good correlation between them was found. (C) 2008 Elsevier Ltd. All rights reserved.
keywords
SILICON-NITRIDE; PHASE-RELATIONSHIPS; WEAR BEHAVIOR; CERAMICS; MICROSTRUCTURE; CRYSTALS; YTTRIUM; STEEL
subject category
Materials Science; Metallurgy & Metallurgical Engineering
authors
Lima, VX; Davim, JP; Cairo, CA; Ferreira, JMF
our authors
José Maria da Fonte Ferreira
Retired Professoracknowledgements
The authors thankful to the Portuguese Foundation for Science and Technology for the financial Support ill the frame of the contract Reference: POCTI/CFM/39419/2001, and to CICECO. Finality the authors acknowledge to M.SC. Student Pedro Reis for your participation in tribological tests.