Abstract
The aging characteristics of various alloys are interpreted satisfactorily from the unified standpoint of view that the formation of the Guinier-Preston (G-P) zone or “Complex” which is a segregation of the solute stoms on the matrix lattice is not a preparative process of precipitation of the new phase. Supersaturation of the solid solution is not necessarily required for the formation of the G-P zone, if the concentration of the solute atoms in the matrix solid solution is suitable. Taking into account the stability of the G-P zone as a function of the concentration of the solute atoms and considering the incubation periods of the formation of the G-P zone and of the precipitation of the new phase, the aging process and the effects of the additional elements and cold working to the aging characteristics are explained. The results of the calorimetric, electrical resistance and X-ray measurements on Al-Cu, Al-Ag, Mg-Pb, Al-Al2Mg3Zn3, Al-MgZn2 etc. are referred to for the discussions.
