Large Area Net-Shaping of Bulk Metallic Glass Sheets
Abstract
Large Area Net-Shaping of Bulk Metallic Glass Sheets Jan Schroers Yale University Within this project we develop and demonstrate a 3D microstructural architecture structure made from bulk metallic glass, 3DMGS, exhibiting a combination of ceramic-like high strength, metal-like high plasticity, and polymer like density. A benchmark material such as a structural steel exhibit plasticity of ~20%, yield strength of 700 MPa and density of 7.9 g/cm3. The specific strength of the proposed 3DMGS will be 6 times higher than that of a typical structural steel. To identify such optimized structure we use our artificial microstructure (AMS) strategy combined with topological optimization algorithms. 3D fabrication methods will be developed that are efficient and scaleable to fabricate optimized structures. To achieve these typically mutual exclusive properties we consider intrinsic length scales of the bulk metallic glasses (BMGs) into the topological optimization process that are realized in efficient structures which go beyond classic designs like the honeycomb structure. Such length scales dictate the deformation and failure mode of the BMG. The advancement from 2D to 3D is led by a topological optimization process which itself combines an iterative communication between the topological optimization algorithm, AMS strategy, and 3D experiments. This allows us to directly realize and characterize structures, which are suggested by the algorithm, into microstructural architectures made in the material of consideration, and at scale, thereby constitutes an efficient and precise development strategy. Our recently developed AMS strategy (2D) is a powerful toolbox for decoding complex microstructures and microstructural architectures and therefore ideally suited for the development of novel microstructural architectures. It is highly versatile in terms of shapes and length scales, features ranging from 10 nm to centimeters can be fabricated. Also a range of materials and material combinations can be used including metals, thermoplastics, and silicon. Significant for the use in a development program is the practicality of our approach. 3DMGS will be fabricated from BMG sheets followed by additional forming and joining techniques. We propose two strategies, both potentially efficient and scaleable to fabricate large quantities of 3D structures. One is based on sequential sheet rolling, punching to perforate the sheets, TPF based out of plane forming, followed by joining the layers. Within the other strategy we pattern the BMG sheets selectively to encourage selective bonding of some regions.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Oct 01, 2019
- Source ID
- W911NF1510212
Entities
People
- Jan Schroers
Organizations
- Army Contracting Command
- United States Army
- Yale University