CAREER: Interface Engineered Amorphous Alloys for Thermoplastic Forming of Ductile Bulk Metallic Glasses

金属玻璃已经发展成为一种新型的高强度工程材料，在航空航天、电子和汽车工业中具有引人注目的优势。然而，它们的技术实用性受到张力局部失效的倾向和批量生产的有限加工路线的阻碍。该学院早期职业发展（CAREER）奖支持研究工程非晶合金结构，具有增强的延展性和可成形性，用于生产大块金属玻璃板。变形行为及其对微观结构变量的依赖性将通过协同计算和实验研究活动来阐明。界面工程块体金属玻璃板将首次通过增材喷涂制造合成，这将为通过热塑性成型设计和生产金属玻璃部件提供无数新的机会。研究活动被整合到新的教育举措中，这些举措促进了少数民族参与计划中代表性不足的学生的参与，为工程专业提供了丰富的课程，并促进了与地区高中建立可持续的机制。 该CAREER奖支持基础研究，以了解界面工程非晶合金中含有过量自由体积晶间区域的应变离域机制。指导性假设是金属玻璃中的剪切局部化可以被过量自由体积的区域中断，过量自由体积促进许多亚临界剪切带的分布式成核，从而通过消除主导剪切前沿产生更均匀的塑性响应。 研究小组将进行剪切局部化的分子动力学模拟，并对界面工程非晶合金进行先进的表征和纳米力学测试，以阐明界面结构和非晶晶粒尺寸在应变离域力学中的作用。增材喷涂制造的创新将被设计成能够通过分布式微塑性有效地使塑性应变的积累离域的转换微观结构。这项研究的主要社会影响是通过增材喷涂制造生产延性非晶合金板材的能力，可用于彻底改变金属板材行业，以及通过净成形热塑性成形工艺生产大块金属玻璃部件。

Metallic glasses have evolved into a new class of high-strength engineering materials with compelling benefits for the aerospace, electronics, and automotive industries. However, their technological utility has been hindered by a propensity for localized failure in tension and limited processing routes for bulk production. This Faculty Early Career Development (CAREER) award supports research to engineer amorphous alloys structures with enhanced ductility and formability for the production of bulk metallic glass sheets. Deformation behavior and its dependence on microstructural variables will be elucidated through synergistic computational and experimental research activities. For the first time, interface engineered bulk metallic glass sheets will be synthesized through additive spray manufacturing, which will provide a myriad of new opportunities for the design and production of metallic glass components through thermoplastic forming. Research activities are integrated into new educational initiatives that advance the engagement of underrepresented students in minority participation programs, provide curriculum enrichment for engineering majors, and facilitate the establishment of a sustainable mechanism for interfacing with regional high schools. This CAREER award supports fundamental research to understand the mechanisms underpinning strain delocalization in interface engineered amorphous alloys containing intergranular regions of excess free volume. The guiding hypothesis is shear localization in metallic glasses can be interrupted by regions of excess free volume that promote the distributed nucleation of many subcritical shear bands, thus producing a more homogenous plastic response via elimination of a dominant shear front. The research team will perform molecular dynamics simulations of shear localization collectively with advanced characterization and nanomechanical testing of interface engineered amorphous alloys to elucidate the role of interfacial structure and amorphous grain size in the mechanics of strain delocalization. Innovations in additive spray manufacturing will be devised to enable transformational microstructures that effectively delocalize the accumulation of plastic strain via distributed microplasticity. A chief societal impact of this research is the ability to produce ductile amorphous alloy sheets via additive spray manufacturing that can be used to revolutionize the sheet metal industry as well as produce bulk metallic glass components through net-shape thermoplastic forming processes.