The influence of temperature and composition on the activation energy for creep in binary aluminum lithium alloys
Seaton, Robert Leonard
McNelley, Terry R.
Kalu, Peter N.
MetadataShow full item record
With the fast pace of technology in the aerospace industry, there are increasing demands for higher strength and stiffness in structural materials but with reduced weight and improved formability. Aluminum alloys have been widely used in the construction of aerospace vehicles because of their high strength to weight ratio, forming characteristics and corrosion resistance. An investigation was conducted to determine the temperature and composition dependence on the activation energy for creep of A1-0.5wt.pct.lithium, A1-1.Owt.pct.Li, and A1-2. Owt.pc+.Li alloys. A series of isothermal tests were conducted utilizing constant true stress creep tests, with nominal temperatures ranging from 300 C to 500 C. Temperature cycling tests involved a range of 10 C for each test. Experimental results indicate all three alloys behave as a class II alloy (pure metal class) with a stress exponent, n, approximately equal to 5. In addition, subgrain formation was observed in association with the primary stage of creep. The activation energy for creep of the A1-0.5wt.pct.Li and A1-1.Owt.pct.Li alloys was observed to b essentially the same as that for pure Aluminum.
RightsThis publication is a work of the U.S. Government as defined in Title 17, United States Code, Section 101. Copyright protection is not available for this work in the United States.
Showing items related by title, author, creator and subject.
Ellison, K.H.; McNelley, T.R.; Fox, A.G. (1993);The elevated temperature deformation behavior of an Al-2. 0 wt pct Li alloy in the temperature range 300 °C to 500 °C was studied using constant extension-rate tension testing and constant true-stress creep testing under ...
Abou-Salama, Ahmed Ahmed (1987-12);Previous research had demonstrated superplastic behavior in aluminum-magnesium alloys of high magnesium content to result from deformation processing to an initially non-recrystallized condition. Analysis here of those ...
van Horn, M.; Smith, P.; Mason, B.P.; Hemmer, J.R.; Read de Alaniz, J.; Hooper, J.P.; Osswald, S. (2015);The development of mechanochromic molecules has opened new pathways for the study of localizedstress and failure in polymers. Their application as stress or temperature diagnostics, however,requires suitable measurement ...