Fig. S1, Fig. S2, Fig. S3, Fig. S4, Fig. S5, Fig. S6

Fig. S1. (a)-(d) Local BSE images near grain boundaries. The precipitates are almost uniformly distributed at grain boundaries and inside the grains. The total fraction of precipitates was estimated to be 2.07% by Image-Pro Plus software. Considering the fraction of grain boundaries, i.e., 1.01%, the fraction of precipitates located at grain boundaries thus was estimated to be 0.02%. Fig. S2. (a) Fractured surface morphology for the directionally solidified Cu64.5Al24Mn11.5 alloy. The Cu64.5Al24Mn11.5 alloy exhibits an exclusively intergranular fracture, cleaving neatly along the boundaries of columnar grains. (b) Fractured surface morphology for the directionally solidified (Cu64.5Al24Mn11.5)99.5Cr0.5 alloy. The insets show the macroscopic morphology after compression. (c) Local morphology of slip bands for the directionally solidified (Cu64.5Al24Mn11.5)99.5Cr0.5 alloy. (d) Local morphology of dimples for the directionally solidified (Cu64.5Al24Mn11.5)99.5Cr0.5 alloy. The (Cu64.5Al24Mn11.5)99.5Cr0.5 alloy displays transgranular fracture morphology characterized by slip bands and dimples due to Cr-rich precipitates. Fig. S3. Mechanical training for the directionally solidified (Cu64.5Al24Mn11.5)99.5Cr0.5 alloy. Fig. S4. Temperature dependence of recoverable strains εrec for the directionally solidified (Cu64.5Al24Mn11.5)99.5Cr0.5 alloy under a compressive stress of 900 MPa. Fig. S5. Temperature dependence of transformation strain εtr (with uncertainties of {plus minus}0.1%) for the directionally solidified (Cu64.5Al24Mn11.5)99.5Cr0.5 alloy. Fig. S6. Evolution of critical stress σMs and the dissipated energy ΔW with the increase of cycles.