Investigation of fracture toughness and fracture mechanisms using acoustic emission measurements

This report is the FINAL PROGRESS REPORT'' for the research program Investigation of Fracture Toughness and Fracture Mechanisms using Acoustic Emission Measurements.'' The time period covered by this report is from 1 March 1988 through August 1991. The research program consisted of three separate but closely related investigations: (1) An Investigation of the Acoustic Emission Generated during the Deformation and Fracture of Premium Grade 4340 Steel as a function of Mechanical Properties. (2) An Investigation of the Acoustic Emission Generated during the Deformation and Fracture of Ti-641-4V Alloys as a Function of Microstructure. (3) An Investigation of the Acoustic Emission Generated from Second Phase Particles in Aluminum-Silicon Alloys as a Function of Second Phase Particle Size and Density. A synopsis of each of the individual investigations including pertinent data and meaningful results will be given in the report. A listing of graduate student involvement, publications and presentations will also be provided