S-200 grade beryllium fracture-toughness properties

Abstract S-200 grade vacuum hot pressed beryllium fracture toughness properties for both longitudinal and transverse orientations were generated in the temperature ranges between −320°F to 500°F and −320°F to 75°F, respectively. Limited data are presented for observations of fatigue behavior, fractography, dynamic and static tensile properties, and dynamic fracture toughness. Statistical bounds are given for fracture toughness data including a comparison of orientation effects. For longitudinally oriented specimens, fracture toughness increased linearly with temperature up to 300°F, and the 500°F results indicated a rapid increase above 300°F. Transverse fracture toughness was significantly higher and increased more rapidly with temperature than the longitudinal fracture toughness. Fatigue precracking experimentation revealed that beryllium does fatigue, but that current ASTM fatigue precracking procedures are impractical for general testing. In comparison to previously published notched specimen data, fatigue precracked specimens yielded significantly lower fracture toughness properties.