Mechanical properties and crystallization kinetics of Er-containing Cu-Zr-Al bulk metallic glasses with excellent glass forming ability

Investigations were carried out to explore the consequences of Er adding on the glass forming ability (GFA), mechanical properties, and crystallization kinetics of Cu50Zr43Al7 bulk metallic glass (BMG). It is found that the (Cu50Zr43Al7)(100-x)Er-x (x = 0, 2, 4, 6 at %) BMGs reflects its best GFA at x = 2 and correlate well with GFA indicator (gamma and K) and thermal stability parameter (AT). The Er-containing BMGs showed high compressive strength and Young module in the range of 1816-1890 Mpa and 116-120 GPa, respectively, but no plastic deformation observed in them. The crystallization kinetics lagged with 2 at % Er addition. The large atomic radius of Er and large negative mixing enthalpy of Er with the other constituent elements causes the significant atomic size mismatch and the formation of short-range order in the melt which restrict the long-range diffusion and ordering of atoms that lead to improving GFA and lagging the crystallization kinetics of (Cu50Zr43Al7)(98)Er-2.