Modulation of structure and mechanical properties in metallic glass composites reinforced with B2 phase by microalloying

This study investigated the impact of Ta on the structure and properties of Zr46Cu46Al4Ti4)100-xTax (x = 0, 1, 1.5, 2 at%) bulk metallic glass composites (BMGCs). The addition of Ta led to a gradual increase in the glass transition temperature, while the crystallization onset temperature remained nearly constant. This resulted in a decrease in the supercooled liquid phase region and a reduction in the glass-forming ability (GFA). The room temperature uniaxial compression tests revealed that the addition of Ta initially increased the plasticity of the alloys, followed by a subsequent decrease. The alloy with 1.5 at% Ta exhibited superior properties, including the highest fracture strength (2033 MPa) and plasticity (8.1 %). The Vickers hardness tests revealed that the addition of Ta led to an increase of the hardness in the glass matrix region of alloys from 512.8 HV to 550.9 HV. In conclusion, a moderate amount of Ta element can enhance both the fracture strength and plasticity of Zr-based BMGCs, as well as improve the hardness of the alloy glass matrix.