Abstract:
Bulk metallic glass (BMG) formers are multicomponent alloys that vitrify with remarkable ease during solidification. Technological interest in these materials has been generated by their unique properties, which often surpass those of conventional structural materials. The metastable nature of BMGs, however, has imposed a barrier to broad commercial adoption, especially where the processing requirements of these alloys conflict with conventional metal processing methods. Research on the crystallization of BMG formers has uncovered novel processing opportunities using thermoplastic forming (TPF), which utilizes the dramatic softening exhibited by a BMG as it approaches its glass transition temperature. Fabrication processes based on TPF decouple the rapid cooling required to form a glass from the forming step, mitigate the effects of heterogeneities on crystallization, and overcome geometrical limitations associated with casting. This talk introduces such techniques that are unique among metals. For example, when TPF based blow molding of BMGs, geometries can be achieved that were preciously unachievable with any other metal processing method. Due to the absence of an intrinsic size limitation and a phase transition first order during solidification, BMGs can be precision net-shaped on the micro, nano and even atomic length scale. Furthermore, these length scales can be combined even on complex surfaces.  Within TPF, BMGs can be considered high strength material that can be processed like (thermo) plastics, whereby previously mutually exclusive attributes of materials –processability and performance – can be combined. Then why besides their superb properties have not been widely used to date will be discussed. This will lead to the requirements of novel alloy development strategies that will allow us to identify bulk metallic glass forming compositions faster. Combinatorial sputtering paired with high-throughput characterization is one such method which will be introduced and discussed on how it can be expanded to multi-parameter optimization process to develop BMG alloys that could be widely adapted by industry.

Biography
Jan Schroers is a Professor in the Department of Materials Science and Engineering, Yale University, New Haven, USA. Prof. Schroers has published ~110 articles, including in Nature, Nature Materials, Nature Communications, Advanced Materials, Phys. Rev. Letters, and so on. His papers have received ~5,000 citations, with an H-index of 34. He has also presented ~30 invited talks at international conferences, as well as many invited seminars. His current research interests ranges over micro & nano replication, MEMs materials & processes, amorphous metallic foams, bulk metallic glasses, bio-medical applications and thermo plastic forming.