摘要
Maxwell-Voigt model with two Kelvin units and one Maxwell unit was utilized to analyze the microalloying effect of Cu on the creep behavior of CoFe-based metallic glasses at different loading rates.The defect activation during creep deformation was detected by the relaxation time spectrum based on this model.The defect,with respect to a short relaxation time in relaxation spectra,intends to be activated at a quasi-static loading mode in the alloy with 0.5 at.%Cu addition.With further increasing loading rates,more defects with a large size were provoked activated at both hard and soft regions in the Cu-containing sample.A softening with the reduction of elastic modulus and hardness about 10%and 15%,respectively,was also observed in the Cu-doped sample.It is consistent with the pronounced viscoplastic deformation of this alloy along with the decrease of viscosity.Our work provides a microscopic insight into structural evolution during creep deformation in a Cu-doped metallic glass,which might help for understanding the plastic deformation of metallic glasses upon a minor addition.
基金
the Natural Science Foundation of Jiangsu Province,China(No.BK20171354)
the National Natural Science Foundation of China(Nos.51631003 and 51601038)
the Key Basic and Applied Research Program of Guangdong Province,China(No.2019B030302010)
the Fundamental Research Funds for the Central Universities(No.2242020K40002)
the Jiangsu Key Laboratory for Advanced Metallic Materials(No.BM2007204)。
