Materials technologist, National Aeronautics and Space Administration, Lewis Research Center, Cleveland, Ohio
Pages: 16 Published: Jan 1979
A heuristic theoretical basis is proposed for the experimental correlations found between ultrasonic propagation factors and fracture toughness factors in metallic materials. A crack extension model is proposed wherein spontaneous stress (elastic) waves produced during microcracking are instrumental in promoting the onset of unstable crack extension. Material microstructural factors involved in this process are measurable by ultrasonic probing. Experimental results indicate that ultrasonic attenuation and velocity measurements will produce significant correlations with fracture toughness properties and also yield strength.
nondestructive evaluation, fracture toughness, ultrasonics, yield strength, stress waves, microstructure, crack propagation, polycrystalline materials
Paper ID: STP34936S