Introduction

The invention concerns a process for the production of a ceramic body comprising nanofibres of silicon nitride or silicon carbide bonded together to form a single body. The process comprises three steps: impregnation of a polyurethane foam with a preceramic polymer, cross-linking of the precursor, pyrolysis of the impregnated polyurethane foam.

Technical features

The invention concerns a process for the production of a ceramic body comprising nanofibres of silicon nitride or silicon carbide bonded together to form a single body. The process comprises the following three steps: impregnation of an open-cell polyurethane foam with a preceramic polymer containing silicon, oxygen, carbon and hydrogen; cross-linking of the precursor; pyrolysis of the impregnated foam at a temperature ranging between 1400 and 1500°C in a controlled atmosphere of nitrogen or an inert gas. The invention concerns also the ceramic bodies obtained according to the process of the invention.

Possible Applications

• Thermal insulation for low and high temperatures;
• High temperature applications;
• Reinforcement for composite materials;
• Support for catalysts;
• Thermal insulation for applications in construction, industry, clothing;
• Filtration of liquids or gases.

Advantages

• High level of thermal insulation;
• Possibility to produce silicon nitride or silicon carbide felts in a controlled form;
• Very high thermal and chemical resistance.