Serrated Behaviors and Plasticity of Nb-Alloyed Cu-Based Bulk Metallic Glasses

Ab Initio Molecular Dynamics Study of the Structure and Properties of Nb-Doped Zr-Cu-Al Amorphous Alloys

“…Due to their formation and properties being very sensitive to the types and contents of constituent elements, some properties of ZrCu-based BMGs can be dramatically changed by doping Nb elements [8][9][10][11][12][13][14][15][16][17][18][19]. In the (Cu 50 Zr 43 Al 7 ) 100-x Nb x (x = 0, 1, 3, 6, 9 at.%) BMGs, the best room-temperature plasticity, and the highest fracture strength and glass transition temperature (T g ) are presented when x = 3 [1].…”

“…Jiang et al [18] studied Cu 48 Zr 48−x Al 4 Nb x (x = 0, 0.3, 0.8, 1.2, 1.5, 2.0 at.%) bulk metallic glass composites (BMGC) and found a BMGC possessing an excellent combination of high strength (~1.3 GPa), and significant tensile plasticity (~8%) was obtained by adjusting Nb content (0.3~0.8 at.%). Wu et al [19] explored Cu 50.2 Zr 40.8 Ti 9−x Nb x (x = 0.5, 1, 2 at.%) BMGs and composites via experiments, found that as-cast alloys with 1.0 at% of Nb element display the large time window of serrated events, implying that the serrated behavior can dynamically retain in a long-time scale and thus the alloy is endowed the largest compressive plasticity. These experimental results demonstrate that the internal structure of ZrCu-based BMGs can be changed significantly by adding a little Nb (less than 3%), thus improving the macroscopic plasticity, but too much Nb added will reduce the plasticity and strength of the alloys.…”