Modulating mechanical properties of Ti-based bulk metallic glass composites by tailoring dendrite composition with Sn addition

The design of highly processable metallic glass matrix composites (MGMCs) is driven by optimizing the mechanical properties such as strength and ductility. In this work, by using X-ray diffraction (XRD), scan electron microscopy (SEM), energy dispersive spectroscope (EDS), transmission electron microscopy (TEM) and compressive testing, we reported that the microstructure and mechanical properties of Ti-based MGMCs can be tuned by a minor addition of Sn. The results revealed a critical content for Sn (i.e., 3 at.%), below which (i.e., 1 at.%-3 at.%), the MGMCs can be strengthened without losing their plasticity. While excessive addition of Sn (i.e., 4 at.%-5 at.%) would degrade severely the plasticity of MGMCs. The Sn element which mainly distributes in the dendrite-phase was found to affect significantly the intrinsic properties of the β-Ti dendrite-phase and should account for the variation of the yield strength and plasticity of MGMCs. Thus, the competing effect between dendrite-phase and glass-matrix in plastic deformation has been discussed in detail. The current work provides further insights to develop MGMCs with enhanced yield strength and graceful plasticity through optimal element addition.