Honeycomb Structures of Bulk Metallic Glasses

Abstract

A combination of lithography and thermoplastic forming allows us to fabricate honeycombs from bulk metallic glass (BMG) precisely and to manipulate its structure selectively. Characteristics of the honeycomb such as the ligament length, thickness, and radius of curvature at the joints of the cells are varied to determine how changes in these characteristics affect properties under uniaxial in‐plane compression testing. It is found that the deformation behavior of BMG honeycombs can be controlled through microstructural design, from brittle to ductile, by changing the length to thickness ratio of the ligaments. The ability to absorb energy of BMG honeycombs exceeds honeycombs of most other materials due to the utilization of a size effect, which result in plasticity. Besides the usage for BMG honeycombs, the technique provides a general method to effectively characterize complex microstructural architectures and tailoring these architectures to the specifications of the material used.

A thermoplastic forming map of a Zr-based bulk metallic glass

“…1c, and is similar to what was reported previously [19,31,32,39]. Hot-embossing experiments were performed at various temperatures, ranging from 310 to 390°C, in the SCLR, with strain rates ranging from 5 Â 10 À4 to 1 Â 10 À1 s À1 , using a Zwick machine (Zwick/Roell 020) equipped with an air furnace.…”

“…Taking advantage of BMGs' superplastic flow in the supercooled liquid region (SCLR), thermoplastic forming (TPF) has been widely employed to fabricate precise and versatile geometries on length scales ranging from 10 nm to several centimeters [18][19][20][21][22][23][24][25][26][27][28][29][30][31][32][33][34][35][36]. The formability has been proposed to be the key property that determines the suitability of BMGs for TPF [37][38][39][40][41][42].…”

Mechanical and Structural Investigation of Porous Bulk Metallic Glasses

“…Unfortunately, the current methods used to fabricate such structures have insufficient control over the arrangement of microstructural features [1][2][3][4]. To overcome this challenge, a novel strategy to analyze microstructure-property relationships was postulated by Sarac et al [5][6][7][8]. The strength and purpose of this method is the ability to vary microstructural features completely independently and to determine the individual effect of these features on the mechanical and morphological response, respectively.…”

“…Particularly interesting is the region where the deformation of the macro-sized samples, defined by global catastrophic fracture, turns into localized shear-induced deformation [6,7]. In this contribution, the toughening mechanism of the porous BMGs in terms of the mechanical and structural changes is investigated.…”

Macroscopic tensile plasticity of Zr-based bulk metallic glass with surface screw thread shaped structure

“…For example, when these SBs are spatially confined under certain loading states, such as the compressive and bending loading, global plasticity has been improved by forming a large number of SBs and stabilizing the propagation of SBs [11,12]. Particularly, various BMGs actually own the local plastic deformation ability even for the brittle Mg-, La-based BMGs [13,14].…”