Navigation

Search This Site

Investigation of Intergranular Corrosion Presence in Marine Grade Aluminum Alloys

Presenters Name: 
Jay Perry
Co Presenters Name: 
Primary Research Mentor: 
Rob Kelly
Secondary Research Mentor: 
Gregory Kubacki
Session: 
2
Location: 
Newcomb Hall Ballroom
Grant Program Recipient: 
USOAR Program
Abstract: 

United States Navy vessels are susceptible to intergranular corrosion due to a humid, chlorine-saturated environment. The presence of copper metal accelerates IGC growth in grain boundaries of aluminum alloys, decreasing the aluminum’s structural integrity and lifetime. To reduce cost and labor of repair and to increase longevity of vessels, resistant alloys are to be employed. This investigation explores variables relating to IGC growth including cathode (Cu) size, aluminum alloy, and degree of sensitization. Analysis of throwing power, surface presence and change in mass yields applicable results to theory of IGC behavior. After testing, IGC was found to be concentrated in close proximity to the cathode, both in throwing power and depth of effect. It was determined that increased cathode size led to higher depth, but no significant increase in throwing power. Sensitization only affected throwing power across samples, not strength. Change in mass reveals an insignificant increase in sensitization, suggesting exponential growth in the rate of IGC growth over time is limited or long-term. The investigation concludes with suggesting tests for these behaviors spanning longer time periods and limiting sample selection to DOS 10,14 with Cu cathodes of .375” to further explore IGC behavior at an upper limit.