The Development of Silicon Nitride to Achieve Higher Inlet Temperatures in Land Based Gas Turbines

The introduction of the gas turbine engine into automotive transport will depend, to some extent, on the achievement of an efficient working cycle. Implicit in this requirement is the operation of the turbine at inlet temperatures in excess of 1500 K where metallic alloys have insufficient strength and corrosion resistance.

Of the ceramic materials being considered for this environment, silicon nitride is the most attractive because of its low coefficient of thermal expansion, good thermal shock resistance, and high strength at these temperatures.

The techniques and processes used in the production of reaction-bonded and hot-pressed silicon nitride are sufficiently advanced to enable predictions of material costs to be made.

Consistent material is now available with well-established physical properties and having potential for further development.