Repeated rejuvenation from relaxed metallic glasses through the memory effect

Rejuvenation through the memory effect has shown huge potential in tailoring both the physical and mechanical properties of relaxed metallic glasses (MGs). Here, the effects of repeated rejuvenation through the memory effect on the mechanical properties and structural changes of the relaxed Zr-based MGs were systematically investigated. Six thermal cycles are conducted on the relaxed samples. When the number of cycles is less than three times, the values of the relaxation enthalpy of all the rejuvenated samples can be recovered 20 % of that of the as-cast sample, and the plastic strains of all the rejuvenated samples are better than that of the as-cast sample. Further increasing the number of cycles to six, the plastic strain gradually decreases and finally becomes lower than that of the as-cast sample. In addition, the evolutions of the boson heat capacity peak and the fictive temperature are also revealed, and all of them show memory effects during the cycles of the relaxation-rejuvenation process. A relationship between the properties and boson heat capacity peak height is discussed. An analysis of the structural changes shows that the increased spatial heterogeneity is responsible for the improved plasticity. The successful repetition of rejuvenation through the memory effect would spark interest in recycling MGs.