Authors: M Riva M J Hoffmann R Oberacker T Fett
Publish Date: 2007/10/16
Volume: 43, Issue: 1, Pages: 402-405
Abstract
SiAlON ceramics are important materials for applications under high mechanical and thermal stress such as cutting tools or engine components These solid solutions offer a wide variety of microstructures and properties depending on composition and sintering parameters As observed in most ceramics also for SiAlON the effect of subcritical crack growth has to be expected However preliminary tests on this material have shown very little subcritical crack growth whereby the determination of the crack growth exponent n causes difficulties This work presents a new method to obtain statistically more significant resultsSiAlON ceramics can be derived from both α and βsilicon nitride modifications by substituting silicon by aluminium and nitrogen by oxygen The possibility to stabilize two crystal structures offers the opportunity to design materials ranging from pure α mixed α/β up to pure βSiAlONs In general αSiAlONs are in the form of equiaxed grains with high hardness and
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