A combinatorial thin film sputtering approach for synthesizing and characterizing ternary ZrCuAl metallic glasses

We report a combinatorial sputtering approach for synthesizing ternary metallic glass alloys on both silicon and sapphire substrates. ZrCuAl metallic-glass thin films were co-deposited using a multi-source radio-frequency magnetron-sputtering process. The combinatorial synthesis process yields a wide range of compositions via a single co-sputter deposition process. The compositions of the films were characterized by the energy-dispersive X-ray spectroscopy (EDS), and the structure of the ZrCuAl alloy thin films was investigated by the X-ray diffraction (XRD). Thorough phase analyses indicated the phases present in the films at different compositions were in good agreement with the binary Zr–Cu phase diagram. Nanoindentation results showed that mechanical properties of the bulk-metallic glasses (BMGs) thin film, such as elastic modulus and hardness, are functions of the Zr (or Cu) concentration. The composition with a moderate Zr content (45 atomic percent (at.%)) resulted in a high film modulus and hardness. The post anneal treatment increased the film elastic modulus and hardness. Small additions of aluminum slightly enhanced the film mechanical properties. Using this combinatorial technique could facilitate the development of the new multi-element metallic-glass alloy, particularly for systems with many elements. The first attempt of casting the optimum resultant ternary BMGs rod was successful.