Silicon nitridation at different nitrogen pressures

The mass change of silicon samples with different initial density, apparent density, ultimate strength and phase composition during nitridation in the nitrogen pressure range 0.002 – 18 MPa is followed. It is shown that rate of the reaction of nitrogen and silicon increases up to nitrogen pressure 1.5 MPa; at higher nitrogen pressures the growth of the reaction rate slows down. Ceramic with relative density 90% and ultimate bending strength 540 MPa was obtained at kilning temperature 1710°C. Ceramic parts serviceable under the actual operating conditions of a real motor have been fabricated for internal combustion engines.