High temperature mechanical behavior of low stiffness Al 2 TiO 5 and Al 2 TiO 5 –3Al 2 O 3 .2SiO 2 –ZrTiO 4 composite materials

Abstract The mechanical behavior of low (and negative) thermal expansion and low stiffness Al 2 TiO 5 materials and Al 2 TiO 5 –3Al 2 O 3 .2SiO 2 –ZrTiO 4 composite materials was studied by diametral compression test at room temperature 400 and 800°C. The effect of both temperature and composition was analyzed. Stress–strain curves were obtained and, from them, apparent elastic modulus ( E app ) and mechanical strength ( σ F ) were determined. Fracture mechanisms and fracture patterns were also analyzed. All materials showed a brittle behavior up to 800°C. The thermal variation of σ F , that was even higher as testing temperature increased, was interpreted based on the microcracks behavior. A double linear correlation of E app was found with temperature ( T ) and zircon content ( [Z] ), with a fitting coefficient > .9. The particular low stiffness and the mechanical and thermal behavior of the studied materials suggest that they would be able to withstand thermal stresses.