Property optimization of Zr-Ti-X (X = Ag, Al) metallic glass via combinatorial development aimed at prospective biomedical application

Exceptional materials with enhanced bio-compatibility are a quest among the researchers in the medical community. Conventional crystalline materials, including 316L stainless steel, titanium and titanium-based alloys, are most commonly used for medical equipment or devices. However, materials with greater compatibility with biological systems should be studied. An amorphous solid, such as Zirconium (Zr)-based metallic glass, is a possible alternative to the conventional crystalline materials. The prospect of achieving multi-property requirements (i.e., high corrosion and wear resistance, lower elastic modulus and enhanced antibacterial capacity) with Zr-based thin film metallic glass (TFMG) were studied in this work. To form a ternary system with the optimized composition of Zr₄₆Ti₄₀Ag₁₄ and Zr₄₆Ti₄₃Al₁₁, TFMGs were fabricated by magnetron co-sputtering or combinatorial development of a binary Zr-Ti alloy with silver (Ag) or aluminum (Al). The structural characterization via grazing incidence x-ray diffraction (GI-XRD) and high-resolution transmission electron microscopy (HR-TEM) manifested an amorphous structure for the ternary TFMGs. The electrochemical analyses of the ternary systems revealed lower corrosion- and passive-current density when compared to 316L stainless steel and commercially pure titanium (cp-Ti). These data demonstrated that TFMGs have better corrosion resistant characteristics. Moreover, the systems exhibited appreciable hardness and elastic modulus lower than 316L stainless steel and cp-Ti. Both of the ternary TFMGs exhibited hydrophobicity, whereas only the Zr₄₆Ti₄₀Ag₁₄ exhibited significant antibacterial properties and reduced the growth of methicillin-resistant Staphylococcus aureus. The combination of such desirable properties makes these TFMGs an excellent candidate material for a wide range of biomedical applications.