Abstract
Corrosion behavior of Si{sub 3}N{sub 4} ceramics in various molten alkali sulfates and carbonates exposed to air and nitrogen gas were investigated at 900{degree} to 1,200{degree}C and 700{degree} to 1,013{degree}C, respectively. The minimum reactant molar ratios of K{sub 2}SO{sub 4}/Si{sub 3}N{sub 4} and K{sub 2}CO{sub 3}/Si{sub 3}N{sub 4} necessary for complete reactions in a nitrogen gas were 1.6 and 3.5, respectively. The surface chemical reaction control shrinking core model adequately described the relation between reaction time and fractional extraction of Si{sub 3}N{sub 4} in alkali sulfate and alkali carbonate exposed to nitrogen gas atmosphere. The apparent activation energies for the reactions of Si{sub 3}N{sub 4} in alkali sulfate and alkali carbonate melts exposed to nitrogen gas were 430 kJ/mol and 106 kJ/mol, respectively, and were independent of the alkali cation species in the melt.
Sign-in/Register to access full text options 
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.
