Fig. 1. The strain as a function of time of La30Ce30Ni10Al20Co10 HE-MG in different states (Samples were aged for a duration from 0 to 6600 s at 363 K). The applied stress is 100 MPa and the creep temperature is 363 K. The solid lines are fitted by a power-law approximation.

Fig. 2. The apparent activation energy spectrum of the La30Ce30Ni10Al20Co10 HE-MG for different degrees of pre-aging.

Fig. 3. (a) The log-log plot of strain rate against creep time. The curve shows three parts of distinct power-law decay, corresponding to fast, second, and slow relaxation modes. Crossovers at times τc1 and τc2 can be clearly seen; (b) The log-log plot of strain rate against creep time of samples aged for 0, 3000 and 6600 s at 363 K; Pre-aging time dependence of power-law exponent γi, i = 1, 2, 3, (c) and crossover times τc1 and τc2 (d). The error bars are from uncertainty of linear fit.

Fig. 4. The strain of La30Ce30Ni10Al20Co10 HE-MG as a function of elapsed time at a constant temperature of 363 K and a fixed applied stress of 100 MPa. The sample is aged at 363 K for 7200 s and the recovery time between two loading cycles is also 7200 s.

Fig. 5. The strain evolution with creep time during the consecutive four creep cycles with an applied stress of 100 MPa at 363 K and recovery times of 300 s (a) and 7200 s (b). the relaxation intensity decreases with the increase of the cyclic times; (c) The log-log plot of strain rate against creep time during the first and last creep cycles of samples aged for 7200 s.

Fig. 6. Evolution of the power-law exponents γ1 (a), γ2 (b), and γ3 (c) as a function of the cycle number and recovery time. The error bars are from the uncertainty of linear fit.

Fig. 7. Evolution of crossover times τc1 (a) and τc2 (b) as a function of cycle number and recovery time.

Fig. 8. Schematic evolution of crossover times τc1 (a) and τc2 (b) as a function of cycle number and the total aging time.