New and improved silicon nitride structural ceramic materials and component fabrication processes are being developed and refined for implementation and insertion into aerospace, industrial, and automotive gas turbine applications. These improved materials and forming processes offer the potential of meeting turbomachinery manufacturers’ performance, quality, cost, and production volume goals. AlliedSignal has developed a new generation of silicon nitride materials with isotropic acicular microstructures that result in a number of property improvements compared to current HIP’ed fine-grained silicon nitride materials. Concurrently, new silicon nitride component forming processes such as gelcasting and refinements of current forming processes such as presintered component machining are being developed and refined to achieve production volume fabrication capability, yields, and short cycle times at low costs. As these materials and component fabrication processes are maturating, a number of applications are being investigated and demonstrated including hot section turbomachinery components for aircraft auxiliary power units (APU’s), industrial gas turbines, and automotive hybrid electric vehicle turboalternators.