Abstract
Abstract The fracture surface energy of a dense pure polycrystalline sample of silicon nitride (Si3N4) has been measured at room temperature by the work-of-fracture method on chevron-notched bend bars. Dense specimens were fabricated by hot isostatically pressing highly pure Si3N4 starting powder at 1950°C under 180 MPa via glass encapsulation. Annealing experiments at 1750°C in a nitrogen atmosphere were also conducted after sintering in order to release internal residual stresses possibly arising from cooling down under high pressure. A value of 10–7 ± 0–8 J m−2was measured in both as-sintered and annealed specimens. According to fractographic observation and calculation of the theoretical compliance of the notched specimen, the present value is regarded as the intrinsic fracture energy of Si3N4 and is to be compared with the markedly higher values commonly measured in alloyed materials.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
