Microstructural Study of Deformation Mechanisms in Polycrystalline α-SiC Deformed at High Temperature

Creep tests in compression have been performed at high temperature (1900 to 2000 °C) on SiC materials hot pressed with Al-based additives. High strain values (up to 43%) could be obtained. Two different behaviours have been observed. A superplastic-like behaviour occurs for grain size ≈ 1·5 μm whereas a strong texturation appears for grain size ≈ 3 μm. The influence of microstructural parameters (amount of intergranular phase, grain size, and dislocation microstructure) is discussed.