Fracture by Superimposing Stress Waves

Abstract

A stress-wave system of three intersecting waves may be generated by electron-pulse techniques. The waves intersect at an angle of 90° and cause a brittle mode of fracture in the superposition interval in otherwise ductile metals. Fractographic investigation shows a peculiar type of intergranular fracture in which individual grains are separated and rotated. Fracture occurs simultaneously at a multitude of locations where the acoustic impedance between individual grain boundaries is sufficiently large.