Investigation of static friction of fiber reinforced borosilicate glass mated to soda lime glass at elevated temperatures

Tribological tests were carried out on a soda lime glass mated to SIC- and C-fiber reinforced borosilicate glass. The static coefficient of friction a nd the transition to sliding were measured using a ring-on-block geometry a t temperatures between 25 and 500 degrees C. The fiber orientation (paralle l or antiparallel) referring to the direction of sliding was varied. The st atic friction coefficient decreased with increasing temperature for both th e SIC and the C-fiber reinforced glass owing to increasing tendency for adh esion and resulting material transfer. At temperatures up to 300 degrees C, there was no difference between the static and the kinetic coefficient ind ependent of the material, whereas the static friction coefficient was lower for parallel than antiparallel fiber orientation. At test temperatures abo ve 300 degrees C and antiparallel fiber orientation, stick-slip effects occ urred under the experimental conditions used. The tribological mechanisms c ould be explained by SEM (scanning electron microscopy) studies of the worn surfaces.