Competing High-Temperature Deformation Mechanisms in Mo(Si,Al)2–Al2O3 Composites

Mo(Si,Al) 2 –Al 2 O 3 composites were tested in four-point bending at 1300 °C. The addition of Al 2 O 3 led to a decrease in grain size, and a subsequent decrease in strength for materials containing up to 15 wt pct Al 2 O 3 . At higher Al 2 O 3 fractions, the decrease in grain size saturates and the strength is recovered as the Al 2 O 3 particles prevent grain boundary sliding.