Modification of structure and property in Zr-based thin film metallic glass via processing temperature control

• Zr-based thin film metallic glass (TFMG) exhibits a wide supercooled liquid region.
• The effect of substrate temperature on the microstructure is considered.
• The short range order cluster can be controlled through processing temperature.
• The hardness of sputtered Zr-based TFMG (7.1 GPa) shows good mechanical property.

The aims of this study are to fabricate the Zr–Cu–Ni–Al thin film metallic glass (TFMG) on silicon substrates by DC magnetron sputtering with single target and to investigate the characteristics of coatings with various substrate temperatures. All the coatings exhibit similar structural and thermal properties, yet the hardness increases with processing temperature. It is demonstrated that amorphous matrix and cluster structure are slightly affected by the processing temperatures due to high cooling rate during deposition and superior glass-forming ability. Besides, atoms and clusters can acquire extra energy via heating substrate to stabilize each cluster, and the amount of free volume is reduced. Thus, the hardness increases with substrate temperature owing to the resistance to the shear band propagation. In summary, this study integrates the correlations among microstructure, thermal and mechanical properties, providing a convenient approach to tune TFMG coating performance.