Silicon carbonitrides - A novel class of materials

H. SCHÖNFELDER; F. ALDINGER; R. RIEDEL

doi:doi:10.1051/jp4:19937199

Numéro		J. Phys. IV France Volume 03, Numéro C7, Novembre 1993 The 3rd European Conference on Advanced Materials and Processes Troisiéme Conférence Européenne sur les Matériaux et les Procédés Avancés


Page(s)		C7-1293 - C7-1298
DOI		https://doi.org/10.1051/jp4:19937199

The 3rd European Conference on Advanced Materials and Processes
Troisiéme Conférence Européenne sur les Matériaux et les Procédés Avancés

J. Phys. IV France 03 (1993) C7-1293-C7-1298
DOI: 10.1051/jp4:19937199

Silicon carbonitrides - A novel class of materials

H. SCHÖNFELDER¹, F. ALDINGER¹ and R. RIEDEL²

¹ Max-Planck-Institute of Metals Research, Laboratory for Powder Metallurgy, Institute of Materials Science, Heisenbergstr. 5, 7000 Stuttgart 80, Germany
² University of Darmstadt, Institute of Materials Science, Hilpertstr. 31, PTZ, Building D, 6100 Darmstadt, Germany

Abstract
Silicon carbonitride monoliths derived from polymer powder compacts via polymer pyrolysis represent a new class of structural ceramic materials due to the complete coalescence of the powder particles during polymer decomposition and the formation of a uniform ceramic matrix free from any grain boundaries or secondary phases. The submicron pore channel system penetrating the material can be minimized in volume by infiltration of liquid polysilazane solution or by post-HIPing so that relative densities of 96 % can be reached. The monoliths are oxidation resistant up to 1600°C in air due to the formation of a highly pure silica oxidation layer and they exhibit a creep rate of 1.10^-6 s^-1 at 1650°C and 30 MPa load. Initially x-ray amorphous silicon carbonitride can be crystallized in nitrogen or in air to form Si₃N₄/SiC or Si₃N₄/SiC/C nanocomposites.