Novel Ta46.5W35Co18.5 thin film metallic glass with excellent corrosion resistance, high hardness and good thermal stability

Abstract Thin film metallic glasses (TFMGs) have attracted great attention due to their excellent functional properties and ease of fabrication as compared with bulk metallic glasses. Among them, TaW-based TFMGs have rarely been studied so far. Here, a novel Ta46.5W35Co18.5 TFMG was successfully developed using a magnetron co-sputtering system. The Ta46.5W35Co18.5 TFMG exhibits high hardness of 12.3 GPa, high elastic modulus of 159 GPa, pronounced plastic deformation behavior, and excellent corrosion resistance, i.e., low passive current density of 7.65 × 10−6 A/cm2 and high corrosion potential of 0.31 V, as well as good thermal stability with high onset crystallization temperature of 1100 K. In addition, the origin of these excellent properties was also investigated in detail by using X-ray diffraction and high-resolution transmission electron microscopy. It was found that, for the Ta46.5W35Co18.5 TFMG, its excellent corrosion resistance may be attributed to the amorphous structure, and the high hardness and good plastic deformation ability are caused by the unique atomic-scale structure with nanocrystals dispersed in the amorphous matrix. This work provides a useful guideline for developing TFMG system combined with excellent corrosion resistance, high hardness, and good thermal stability.