Accession Number : ADA562767


Title :   The Effect of Sensitization on the Stress Corrosion Cracking of Aluminum Alloy 5456


Descriptive Note : Master's thesis


Corporate Author : NAVAL POSTGRADUATE SCHOOL MONTEREY CA


Personal Author(s) : Cormack, Emily C


Full Text : https://apps.dtic.mil/dtic/tr/fulltext/u2/a562767.pdf


Report Date : Jun 2012


Pagination or Media Count : 101


Abstract : This work examines the effect of sensitization on the stress corrosion cracking behavior of marine grade aluminum alloys (Al-Mg). These alloys can be sensitized during operation, promoting their susceptibility to intergranular stress corrosion cracking (IGSCC). Aluminum alloy 5456-H116 (also identified as Al-Mg5.1) samples were sensitized at 175 C for varying durations of time and then mechanically tested in salt water. Mass loss tests quantified the degree of sensitization (DOS) as a function of sensitization time. Dual cantilever beam tests were used to measure the SCC growth rate and cyclic fatigue tests were conducted to determine the corrosion fatigue behavior. DOS increased as sensitization time increased with little difference in mass losses above 336 hours. Stress corrosion crack growth rate increased as sensitization time increased. Although the sensitization rates for AA5456-H116 were higher than for AA5083, the stress corrosion crack growth rates were significantly lower. The stress corrosion fracture surfaces showed clear showed a clearly intergranular fracture path with extensive crack branching and delamination in the transverse direction.


Descriptors :   *ALUMINUM ALLOYS , *STRESS CORROSION , CANTILEVER BEAMS , CRACKS , CYCLIC TESTS , DELAMINATION , FATIGUE TESTS(MECHANICS) , FRACTURE(MECHANICS) , SALT WATER , THESES


Subject Categories : Properties of Metals and Alloys


Distribution Statement : APPROVED FOR PUBLIC RELEASE