Date of Award

Spring 1978

Document Type

Thesis

Department

Mechanical & Aerospace Engineering

Program/Concentration

Mechanical Engineering

Committee Director

S. G. Cupschalk

Committee Member

M. W. Hyer

Committee Member

R. M. Sundaram

Call Number for Print

Special Collections; LD4331.E56K95

Abstract

X-ray observations of fatigue fracture and deformed surfaces of 7075-T6 aluminum were conducted in this study. The (111) and (222) diffraction peaks were obtained from the fractured and deformed surfaces. It was observed that in comparison with the base metal, the fracture exhibited line broadening similar to that due to cold working. The broadening is indicative of plastic deformation in the vicinity of the advancing crack tip during the fracture process. Also the different regions of fracture exhibited varying degrees of line broadening. With respect to the fatigue crack, the slow crack growth region showed a greater broadening, and, hence, a smaller particle size, than the fast crack growth region. By means of a modified residual stress device, it was determined that the depth of x-ray penetration did not exceed the thickness of the deformed material at the fracture surface. From an analysis of fracture and deformed surfaces, roughness of the fracture surface was not observed to affect the shapes of x-ray diffraction peaks.

Rights

In Copyright. URI: http://rightsstatements.org/vocab/InC/1.0/ This Item is protected by copyright and/or related rights. You are free to use this Item in any way that is permitted by the copyright and related rights legislation that applies to your use. For other uses you need to obtain permission from the rights-holder(s).

DOI

10.25777/9spk-nx74

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