Atomistic Simulation on the Mechanical Properties of Diffusion Bonded Zr-Cu Metallic Glasses with Oxidized Interfaces

Abstract

A novel welding technique of diffusion bonding for Zr-Cu metallic glass with pre-oxidized surfaces is proposed in this study, which is systematically investigated by molecular dynamics (MD) simulation. Compared with the conventional welding technique, the diffusion bonding process can be well implemented below the crystallization temperature of metallic glass. The obtained structure possesses glass-glass interfaces (GGIs) similar with those in nano-glasses.As revealed by MD simulation, the diffusion bonded metallic glasses possess enhanced mechanical strength and ductility that generally do not exist in nano-glasses and their bulk metallic glass counterparts. The GGIs are found to hinder the propagation of shear bands, where there is strong bonding between Zr and O and the segregated Cu and ZrO2 clusters could induce extra plasticity. The results demonstrate that the diffusion bonding of metallic glass with preoxidized surfaces could provide an alternative approach in solving the longstanding issue of size limitation on metallic glasses. I. INTRODUCTIONAmorphous alloys, also known as metallic glasses (MGs), possess outstanding mechanical properties including high mechanical strength and excellent corrosion resistance, and are promising for structural applications [1]-[2]. Even though different MGs with a variety of compositions have been fabricated in the past decades, the MGs are still not large enough in physical dimensions (< 10 cm) due to the fast quenching rate required for suppressing crystallization. Meanwhile, conventional welding technique cannot be applied to MGs due to high temperature profiles at heat affected zone (HAZ) that might induce crystallization. The mechanical properties of MG might be greatly deteriorated if low-temperature (< 500 o C) solders are used in the welding process. Therefore, to overcome the size limitation on MGs, other welding techniques for MGs should be further investigated and developed. By far, only a few studies have been reported, demonstrating the feasibility of friction, electron-beam, spark, pulse-current and explosive jointing techniques in wedding MGs [3]-[7]. However, those alternative approaches are not suitable for massive manufacturing and the processing parameters must be precisely controlled. Moreover, the mechanical performances of MGs welded by those approaches are at best compatible to those of as-prepared MGs. Recently, a novel type of nanomaterial, named as nano-glass, has been successfully prepared, which consists of numerous glass-glass interfaces (GGI) connecting different nanosized MG clusters or particles [8]-[11]. It is mainly synthesized by inert gas condensation, magnetron sputtering, serve plastic deformations and electrodeposition. Among these techniques, inert gas condensation is the most commonly used one, which produces nanoglasses by compacting nano-sized MG clusters under high external pressure (>100 MPa) and This is the Pre-Published Version.

The Modulation of Compositional Heterogeneity for Controlling Shear Banding in Co-P Metallic Nanoglasses

“…For instance, Adibi et al [ 40 , 41 ] demonstrated the capability of shear bands in NGs to be uniformly distributed within the GGI regions, which was further explained by Wang et al [ 42 ], who demonstrated that the GGIs would promote the plastic deformations in NGs. In other words, the GGIs could significantly influence the shear banding in NGs [ 43 , 44 , 45 , 46 , 47 , 48 ], although a viable strategy for controlling shear banding through alternating the glass phase of GGIs is yet not available, which is critical to further improving the ductility of NGs.…”

Neural network potential for Zr–Rh system by machine learning

“…Metallic glasses (MG) have attracted many attentions owing to the particular performances in structures and properties different from the crystalline phases [1][2][3][4][5][6][7]. Zr-based MG are widely used in vehicle parts, sports equipment and so on, attributing to the superb mechanical properties [8][9][10].…”