1995 Volume 103 Issue 1203 Pages 1205-1207
Corrosion tests of various ceramics sustained in low concentration-H2SO4 were carried out. We also tried to qualitatively detect the damaged surface layer by using the change in the natural frequency of a specimen. The following results were obtained. (1) The weight of Si3N4 and SiAlON decreased rapidly after 5×103 min of corrosion time. However, the weights of Al2O3, SiC and ZrO2 did not change. (2) The weight loss was hardly affected by the concentration of sulfuric acid. (3) The damaged surface layer was qualitatively detected by using the natural frequency change of a specimen.
