The formation of aluminium nitrideboron carbidealuminium composites by wetting assisted infiltration

Abstract

Abstract The possibility of producing aluminium matrixed aluminium nitrideboron carbide composites by pressureless wetting assisted infiltration has been shown. Cold isostatically pressed cup-shaped preforms of boron carbide (1–10 wt%) aluminium nitride mixtures were sintered at 1400–1600 °C in nitrogen atmosphere and then infiltrated with aluminium under 6.5 kPa argon at 1250 °C. Pore diameter in the preforms increased with increase in sintering temperature. Infiltrated samples which were sectioned and polished showed no infiltration front. Higher B 4 C contents (4–10%) and sintering temperature (1600 °C) resulted in full infiltration. In the sintered preforms AlN was the only phase observed. However, in the infiltrated materials both AlN and Al were observed.