Pressureless Sintering of SiC‐Whisker‐Reinforced Al ₂ O ₃ Composites: II, Effects of Sintering Additives and Green Body Infiltration

Abstract

Pressureless sintering of SiC‐whisker‐reinforced Al 2 O 3 composites was investigated. In Part II of the study, the effects of Y 2 O 3 /MgO sintering additives and green body infiltration on densification behavior and microstructure development are reported. Both sintering additives and green body infiltration resulted in enhanced densification. However, the infiltration approach was more effective for samples with high SiC whisker concentrations. Samples with 27 vol% whiskers could be pressureless sintered to ∼93% relative density and ∼3% open porosity. Fracture toughness values and microstructural features (e.g., grain size) for the infiltrated samples remained approximately the same as observed in the uninfiltrated samples.