Detailed X-ray peak-shift, peak-asymmetry and peak-broadening analyses were performed on X-ray diffraction line profiles obtained from cold-worked filings of five compositions of Cu-Al alloys in the fcc phase: Cu-3.7, 6.7, 12.3, 14.9 and 18.4at%Al. The analysis revealed an increased presence of stacking faults of an intrinsic nature. These were primarily responsible for the observed peak shift and domain size peak broadening. A very small presence of extrinsic stacking faults accounted for the observed asymmetry in the profiles, and the twin faults were nearly absent. The effective particle sizes decreased and microstrains increased with increasing solute concentration, and these changes were anisotropic in nature. An estimation of dislocation density and stacking-fault energy for the alloys tended to predict a reasonably good value, 27mJ/m2, for pure copper. Annealing of three alloys having an increased concentration of solute Al did not clearly reveal any detectable evidence of solute segregation at the stacking faults.

An X-Ray Diffraction Study of Lattice Imperfections in Cold-Worked Face-Centered-Cubic Alloys. VI. Copper-Aluminum (α phase). S.K.Pradhan, A.K.Maity, M.De, S.P.Sen Gupta: Journal of Applied Physics, 1987, 62[4], 1521-3