The Propagation of Stress Corrosion Cracks in Alpha-Brasses

An investigation was conducted on the propagation of transgranular and intergranular stress corrosion cracks in commercial grade alpha-brasses tested in a tarnishing ammoniacal solution. Observation of the surface crack traces indicated that the transgranular cracks propagated discontinuously by the sudden appearance, in its entirety, of a fine crack extending several microns ahead of the previous crack tip. The appearance of this fine crack was often associated with the detection of a discrete acoustic emission (AE). By periodically increasing the deflection during these studies, crack front markings were produced on the resulting fracture surfaces and these showed that the crack front at the free surface did not lag behind the overall crack front. This indicated that the discontinuous propagation of the crack trace was representative of the subsurface cracking. The intergranular crack trace appeared to propagate continuously at a relatively blunt crack tip and was not associated with discrete AE.

Name thesis:degree_name

Ph.D.

Level thesis:degree_level

Dissertation

Discipline thesis:degree_discipline

Metallurgical Engineering

Grantor

University of Illinois at Urbana-Champaign

Year dc:date

2014

Author dc:creator

• Beggs, Dennis Vinton

• Engineering, Metallurgy

Language dc:language

eng

Identifier

(UMI)AAI8119632

OAI identifier oai:identifier

oai:www.ideals.illinois.edu:2142/68651