Formation and mechanical properties of a Zr73Al8Cu6Ni13 bulk metallic glass composite containing in-situ beta-Zr dendrites

The variations of structure and mechanical properties with sample diameter (d) for ZrAlCuNi alloys containing a high Zr content of 73 at.% were investigated. A Zr73Al8Cu6Ni13 alloy forms a single glassy phase with a d of 1.0 mm and changes to a composite of β-Zr dendrites dispersing homogeneously in metallic glass matrix when the d increases to 1.5–3.0 mm. The Zr73Al8Cu6Ni13 bulk metallic glass composites (BMGCs) exhibit high compressive plastic strain of over 35% without final failure, superior to that of 4.5% for the ϕ1.0 mm bulk metallic glass (BMG) sample, and the yield strength of ∼1510 MPa is comparable to the BMG. The mechanisms of formation of the β-Zr dendrites and plasticity improvement of the BMGCs were also discussed. •A Nb/Ta-free Zr73Al8Cu6Ni13 BMGC containing in-situ β-Zr dendrites was fabricated.•The BMGC has compressive σy of 1510 MPa and εp of over 35% without final fracture.•High content of Zr facilitates β-Zr dendrites formation under proper cooling rate.