Burner rig hot salt corrosion of silicon nitride
Tests carried out in a low velocity burner rig with a salt contaminated combustion atmosphere in the temperature range 800 C to 1300 C show that sodium accelerates the rate of oxidation of Si(3)N(4). Liquid phase corrosion attack can occur in a manner similar to Type I hot corrosion of superalloys, but at a comparatively lower rate. At temperatures exceeding the dew point of sodium sulphate, above 1000 C at atmospheric pressure, liquid phase attack of the ceramic is not observed and the rate of reaction approaches that of pure oxidation. Reduced strength of the ceramic appears to be due to attack of the grain boundary sintering additives which results in the formation of surface pits. Corrosion kinetics of the Si(3)N(4) are presented and the degradation mechanism is discussed.
Bibliographic Reference: Paper presented: Materials for Advanced Power Engineering, Liège (BE), October 3-6, 1994
Availability: Available from (1) as Paper EN 38347 ORA
Record Number: 199410847 / Last updated on: 1994-11-28
Original language: en
Available languages: en