Accession Number : AD0698017

Title :   MICROSCOPIC MOVIE OF FATIGUE INDUCED CRACK INITIATION AND PROPAGATION,

Corporate Author : IOWA UNIV IOWA CITY DEPT OF MECHANICAL ENGINEERING

Personal Author(s) : Duncan,R. E. ; Stephens,R. I.

Report Date : AUG 1969

Pagination or Media Count : 9

Abstract : A motion picture taken through an optical microscope was made in an attempt to better understand the mechanisms of fatigue crack initiation, propagation and fracture in metals. The primary usage of the movie is that of a visual educational training aid. The movie qualitatively compares crack initiation and propagation in a low carbon steel under the following conditions: (a) low cycle fatigue (less than 50,000 cycles to failure) photographed at 16X, 150X, and 300X magnification; (b) high cycle fatigue (about 1 million cycles to failure) photographed at 300X magnification. Under these conditions the movie shows the interaction of slip lines, slip bands, crack tip, grains and grain boundaries under cyclic conditions. (Author)

Descriptors :   (*METALLOGRAPHY, STEEL), (*STEEL, CRACK PROPAGATION), (*TRAINING FILMS, REVIEWS), FATIGUE(MECHANICS), CRACKS, FRACTURE(MECHANICS), MICROSCOPY, MICROSTRUCTURE, GRAIN STRUCTURES(METALLURGY), GRAIN BOUNDARIES

Subject Categories : Humanities and History
      Properties of Metals and Alloys

Distribution Statement : APPROVED FOR PUBLIC RELEASE