- 一般社団法人 軽金属学会
- 軽金属 (ISSN:04515994)
- vol.29, no.8, pp.315-321, 1979-08-30 (Released:2008-10-30)
Measurements of electrical resistivity and intensity of small-angle X-ray scattering and transmission electron microscopy were made on several compositions of Al-Zn alloys. G. P. zones are formed above the spinodal temperature in the nucleation-and-growth mechanism. The nucleus has a critical size for growth. This size becomes larger when aged at higher temperatures. The G. P. zones formed in this mechanism distribute broadly, but those formed by the spinodal decomposition do closely. The number of G. P. zones is much larger in the latter case (127°C) than that in the former (132°C). The spinodal temperatures estimated for Al-10.0, 12.5, 15.0 and 20.0wt% Zn alloys are 90-95°, 105-110°, 125-130° and 170-180°C respectively. The critical temperatures below which G. P. zones are observed in these alloys are 105-115°, 125-135°, 150-160° and 200-210°C respectively.