Monitoring the Evolution of the Matrix Copper Composition in Age Hardenable Al-Cu Alloys
Nuclear magnetic resonance (NMR) was used to systematically monitor the amount of copper in the matrix of various age hardenable Al-Cu alloys as a function of ageing treatment. These NMR results were used to compare the measured amount of copper residing in the matrix during microstructural evolution with that suggested from the equilibrium phase diagrams. Our results indicate that the matrix copper composition for under- and peak-aged microstructures is generally far from equilibrium, with much more copper in solution than expected based on equilibrium phase diagrams. NMR is shown to be a sensitive and efficient metallurgical characterization technique to monitor the partitioning of solute in both non-equilibrium and equilibrium phases.
W.J. Poole, M.A. Wells and D.J. Lloyd
K. M. Nairn et al., "Monitoring the Evolution of the Matrix Copper Composition in Age Hardenable Al-Cu Alloys", Materials Science Forum, Vols. 519-521, pp. 591-596, 2006