Paper number 802

FRICTIONAL BEHAVIOUR OF THE INTERFACE IN SIC MONOFILAMENT MODEL COMPOSITES WITH BOROSILICATE GLASS MATRIX

H. Cherouali, N. Louet, P. Reynaud and D. Rouby

Groupe d'Etudes de Métallurgie Physique des Matériaux
GEMPPM UMR CNRS 5510, INSA de Lyon,

Summary

A better knowledge of the cyclic fatigue effects in ceramic matrix composites needs a deeper understanding of the microscale mechanisms operating during friction between fibre and matrix. The present work deals with single filament model composites submitted to push-out tests at room temperature. Emphasis is made here on the effect of sliding velocity. The monofilament composites are made with a borosilicate glass matrix (Pyrex) and two types of silicon carbide filaments: SiC SCS-6 from Textron (coated with 3 ?m pyrocarbon) and SiC Sigma from BP (nominally uncoated). The composites have been tested by a succession of push-out and push-back runs. The changes of frictional force are analysed as the drive velocity is suddenly changed: the SCS-6/Pyrex system exhibits the well known velocity weakening whereas an opposite behaviour is observed with the Sigma/Pyrex system. Qualitative and quantitative aspects of these results are discussed as regards to the mechanisms operating at the contact between the sliding surfaces.

Keywords

glass matrix, silicon carbide monofilament, push-out test, interface behaviour, dry friction, stick-slip, sliding velocity, tribology.