SPARK PLASMA SINTERING OF CERAMIC MATRIX COMPOSITES WITH SELF-HEALING MATRIX

• Published in: Ceramic Engineering and Science Proceedings pp. 177 - 186
• Main Authors: Magnant, J, Maille, L, Pailler, R, Guette, A
• Format: Journal Article
• Language: English
• Published: 01.01.2015
• Subjects: Barometric pressure; Ceramics; Preforms; Self healing materials; Silicon nitride; Sintering; Spark plasma sintering; Titanium diboride; Yttrium oxide
• ISBN: 1119031184; 9781119031185
• ISSN: 0196-6219

A mixture of Si3N4 and TiB2, with Al2O3 and Y2O3 as sintering aids, was ball milled, dried and spark plasma sintered under an axial pressure of 30 MPa in an argon or nitrogen atmosphere to temperatures in the range 1450-1750 C, with a hold time at top temperature of 1-20 min. The sintered materials were characterised by determinations of bulk density and phase composition. A pyrolytic carbon coating was deposited on multi-direction carbon fibre preforms by CVI, and composites prepared by slurry infiltration of the preforms using a mixture of Si3N4, TiB2, Al2O3 and Y2O3 followed by spark plasma sintering at 1500 C, hold time 3 min, under an axial pressure of 30 MPa in a nitrogen atmosphere. This firing cycle gave full matrix consolidation without fibre degradation. A flexural strength of approximately 300 MPa was achieved, and the composites exhibited self-healing behaviour on oxidation in air at 850 C for 13 h.