Aging kinetics of aluminum alloy 7050

Precipitation hardening at room temperature (natural aging) and isothermal precipitation hardening at 422 to 455 K beyond the point of peak strength (overaging) were studied. Natural aging kinetics of the increase in strength and resistivity were comparable with those of alloy 7075. Alloy 7050, however, develops peak strength by aging at higher temperatures. This ability of 7050 to develop peak strength upon aging in the temperature region used to improve the resistance to stress-corrosion cracking and toughness of 7XXX alloys is attributed to the effect of Cu on increasing the temperature range of G.P zone stability.