Additive Manufacturing of Advanced Multi‐Component Alloys: Bulk Metallic Glasses and High Entropy Alloys

Abstract

Bulk metallic glasses (BMGs) and high entropy alloys (HEAs) are both important multi-component alloys with novel microstructures and unique properties, which make them promising for applications in many industries. However, certain hindrances have been identified in the fabrication of BMGs and HEAs by conventional techniques due to the intrinsic requirements of BMGs and HEAs. With the advent of metal additive manufacturing, new opportunities have been perceived to fabricate geometrically complex BMGs and HEAs with tailorable microstructure theoretically at any site within the specimen, which are not achievable using conventional fabrication techniques. After providing some background and introducing the conventional fabrication techniques for BMGs and HEAs, this review will focus on the current status, development, and challenges in metal additive manufacturing of BMGs and HEAs including different additive manufacturing techniques being used, microstructure design and evolution, as well as properties of the fabricated BMGs and HEAs. A future outlook of metal additive manufacturing of BMGs and HEAs will also be provided at the end.

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“…Optimal specific strength is 142.6045kPam3/kg for yield strength, 282.7679 kPam3/kg for ultimate tensile strength and specific modulus is 80.0959 MPam3/kg. Optimal density is obtained as1.8247 g/cm 3 .…”

“…The results show that the optimal value of yield strength was 260.21 MPa, the optimal ultimate tensile strength was 515.96 MPa and the optimal value of Young's modulus was 146.15 GPa with the following alloy composition by weight: 89.429% for magnesium, 8.159% for aluminium, 0.344% for copper, 0.255% for manganese and 1.814% for zinc. The optimal alloy composition had a low density of 1.79 g/cm 3 and a high specific strength of 288.22 MPa/g/cm 3 . The microstructure simulation suggests that the optimal alloy has a fine-grained structure with uniform distribution of intermetallic phases.…”

Metallic glass roadmap

“…Besides ML and high-throughput approaches, there are also emerging alloy processing techniques, such as ultrasonic vibration [402] and additive manufacturing [403]. Such techniques essentially involve bonding small pieces of alloy by injecting different forms of energy such as force, heat, and light (vibration, laser, electron beam, plasma, etc) [404][405][406].…”

Recent Advances in Metallic Glasses

“…Industrial applications of metallic glasses have traditionally been limited by issues such as poor machinability and small critical casting dimensions required to achieve an amorphous structure [2,17]. However, over the last decade, additive manufacturing (AM) processes have overcome these issues, and are able to produce amorphous metallic structures with few constraints on dimensions or geometric complexity [92,175,176]. Importantly, additive manufacturing has been successfully applied for numerous alloys with both high and low GFA, including systems based on zirconium [177,178], titanium [179,180], copper [181], nickel [182,183] and iron [54,184,185].…”