Study on Mechanical Relaxations of 7075 (Al–Zn–Mg) and 2024 (Al–Cu–Mg) Alloys by Application of the Time-Temperature Superposition Principle

Table 3

Activation energy in the Arrhenius-type equation for the shift factor for Al–Zn–Mg alloys.

Temperature region	in Arrhenius-type equation for
	From data [eV/atom]	From data [eV/atom]
Low temperature (AA 7075-T6)	0.30	No master curve was
High temperature (AA 7075-T6)	0.60	0.60
Low temperature (AA 7075)	0.30	No master curve was
High temperature (AA 7075)	0.60	0.60

values of activation energy below 0.01 eV/atom (with little physical significance) resulted in an acceptable degree of superposition of curves. Therefore, this result was disregarded.