Structure change during reversion below the G.P. zone solvus has been investigated by means of synchrotron radiation small-angle X-ray scattering (SR-SAXS). The whole process was found to be divided into two periods., i.e., the reversion and the subsequent coarsening period. From the two-phase analysis, it was suggested that the solute concentration of G.P. zone decreases, but the zone size does not change in the first stage, and then the zone shrinks without composition change at the later stage of reversion. The present experimental results agreed well with those obtained by computer simulations.
(Received June 29, 1989)
Keywords: reversion, aluminum-zinc alloys, Guinier-Preston zone, synchrotron radiation small-angle X-ray scattering (SR-SAXS), Johnson-Mehl-Avrami equation, two-phase diffusion equation
*Department of Metallurgy, Kyoto University, Yoshida-Honmachi, Sakyo-ku, Kyoto 606, Japan.
**Photon Factory, National Laboratory for High Energy Physics, Oho 1-1, Tsukuba 305, Japan.
***Research Laboratory of Industrial Materials, Tokyo Institute of Technology, Nagatsuda, Midori-ku, Yokohama 227, Japan.