Method for Determining Tensile Properties of Refractory Materials at Elevated Temperatures*

A bstract Equipment for testing ceramic materials to temperatures of 2000°F. was developed, and a method was devised for evaluating the bending stresses introduced by the test equipment. With this equipment, the tensile strength, stress‐to‐rupture characteristics, and modulus of elasticity of a sillimanite refractory were investigated at the Cleveland Laboratory of the National Advisory Committee for Aeronautics. The tensile strength varied from a minimum of 8000 lb. per sq. in. at 500°F. to a maximum of 19,000 lb. per sq. in. at 1800°F. Heat‐treating the tensile specimens for one half hour at 1800°F. increased the tensile strength 35% at room temperature and 70% at 500°F. No increase in strength was noted at or above 1400°F. The stress‐to‐rupture in 1000 hours at 1600°F. was 8500 lb. per sq. in. The modulus of elasticity at room temperature was 20.3 × 10 6 .