Abstract
It is known that bulk metallic glasses follow simple composition formulas [cluster](glue atom)1 or 3 with 24 valence electrons within the framework of the cluster-plus-glue-atom model. Though the relevant nearest-neighbor cluster can be readily identified from a devitrification phase, the glue atoms remains poorly defined. The present work is devoted to understanding the composition rule of Fe-(B,P,C) based multi-component bulk metallic glasses, by introducing a cluster-based eutectic liquid model. This model regards a eutectic liquid to be composed of two stable liquids formulated respectively by cluster formulas for ideal metallic glasses from the two eutectic phases. The dual cluster formulas are first established for binary Fe-(B,C,P) eutectics: [Fe-Fe14]B2Fe + [B-B2Fe8]Fe ≈ Fe83.3B16.7 for eutectic Fe83B17, [P-Fe14]P + [P-Fe9]P2Fe≈Fe82.8P17.2 for Fe83P17, and [C-Fe6]Fe3 + [C-Fe9]C2Fe ≈ Fe82.6C17.4 for Fe82.7C17.3. The second formulas in these dual-cluster formulas, being respectively relevant to devitrification phases Fe2B, Fe3P, and Fe3C, well explain the compositions of existing Fe-based transition metals-metalloid bulk metallic glasses. These formulas also satisfy the 24-electron rule. The proposition of the composition formulas for good glass formers, directly from known eutectic points, constitutes a new route towards understanding and eventual designing metallic glasses of high glass forming abilities.
Highlights
Since their first synthesis in 1995, Fe-based bulk metallic glasses (BMGs) have drawn increasing attention due to their soft magnetic properties, high glass forming ability, excellent corrosion resistance, and low manufacturing cost[1,2,3,4,5,6]
An amorphous structure of high glass forming ability is dissociated into a characteristic first-neighbor cluster plus one or three glue atoms located between the clusters
Two major steps are: (1) analyzing a binary devitrification phase to obtain the principal cluster for use in the relevant glass-forming cluster formula, and (2) matching one or three glue atoms to the principal cluster so that e/u ≈ 24
Summary
Cluster formulas [B-B0.8Si1.2M8]M1 [B-B1.2M8.8]M1 [B-B1.2M8.9]M1 [B-B1.4M8.6]M1 [B-B1.6Y0.7M7.6]M1 [B-B1.6Sc0.7M7.6]M1 [B-B1.6Er0.7M7.6]M1 [B-B0.8M9.2]M1 [B-B0.8Ga1.8M7.4]M1 [B-B1.4Zr1.2M7.4]M1 [B-B2.6M7.4]M1 [B-B2.8M7.2]M1 [B-B2.7M7.3]M1 [B-B2.4M7.6]M1 [B-B1.8M8.2]M1 [B-B1.9Y0.6M7.5]M1 [B-B0.2Si1.1P0.6M8.1]M1 [B-B1Si1M8]M1 [B-B0.7Si1.2M8.1]M1 [B-B1.3Si0.6M8.1]M1 [B-B1.3Si0.6M8.1]M1 [B-B1.3Si0.6M8.1]M1 [B-B1.3Si0.6M8.1]M1 [B-B1.4Si0.5M8.1]M1. Existing Fe-(B,C,P)-based multi-component compositions with good glass forming abilities are carefully scrutinized using the proposed binary basic formulas within the framework of the cluster-plus-glue atom model. Note that here we deal with the global packing efficiency of the whole cluster formula, including both the cluster and the glue atom parts, which is different from the atomic packing efficiency of the cluster itself[39, 85] In Fe-C-based BMGs, the composition with maximum glass diameter thickness, Fe39Cr15Mo14Co9B6C15Y2, is interpreted by the cluster formula [C-M9]Y0.3(B0.8C0.9)M1. E/u is calculated, i.e., 25.5, which is much less than previously calculated using the binary cluster radius
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
