Effect of cooling rate on the crystallization and mechanical behaviour of Zr–Ga–Cu–Ni metallic glass composition

• MG synthesized at a faster cooling rate contains the large free volume and highest shear band density.
• Ribbons synthesized at slow cooling rate exhibits higher hardness and yield strength.
• Variation in the mechanical behaviour is discussed on the basis of free volume theory.
• Study is focused on the correlation between cooling rate and mechanical behaviour.

The effect of cooling rate on the mechanical behavior of Zr–Ga–Cu–Ni melt-spun glassy alloys has been studied using micro-indentation technique. The ribbons of alloy have been synthesized at three cooling rates corresponding to wheel speeds of 30, 40 and 50 m/s. The glass forming indicators and indentation characteristic have been investigated. The measurements by differential scanning calorimeters show that the ribbons synthesized at faster cooling rate contains larger amount of heats of relaxation, crystallization enthalpy and free volume. The indentation experiments demonstrate that with the same chemical composition, the ribbons synthesized at slow cooling rate exhibits higher hardness and yield strength than those synthesized at faster cooling rate. The ribbons synthesized at 50 m/s contains the large free volume and thus favors the formation of shear bands. The study is focused on investigations of these materials to understand the correlation between the cooling rate and the mechanical behavior of these alloys.

This work makes investigations on the cooling rate effect on the crystallization and mechanical behaviour of Zr69.5Ga7.5Cu12Ni11 metallic glass. The ribbon synthesized at a faster cooling rate contains a larger amount of heats of relaxation and free volume which favours the formation of shear bands. A slow cooling rate results in the higher value of hardness and yield strength for the alloys. The variation in the mechanical behaviour is explained on the basis of free volume theory. The study is focused on investigations of these materials to understand the correlation between the cooling rate and the mechanical behavior of these alloys.Figure optionsDownload as PowerPoint slide