Thermal and mechanical properties of the Zr 53Cu 30Ni 9Al 8 based bulk metallic glass microalloyed with silicon

Abstract

The amorphous alloy rods of (Zr 53Cu 30Ni 9Al 8) 100− x Si x ( x = 0.25, 0.5, 0.75, 1) with a diameter of 2–6 mm were prepared by drop casting method in an Ar atmosphere. The thermal properties, including glass forming ability (GFA) and thermal stability during isothermal annealing of these amorphous alloys, and the mechanical properties have been systematic investigated by the combination of DSC, XRD, SEM, TEM, and compression test. The result of X-ray diffraction reveals that these entire (Zr 53Cu 30Ni 9Al 8) 100− x Si x alloy rods exhibit a typical amorphous diffraction pattern with only a broad maximum around 2 θ around 40 degree. Both T g (glass transition temperature) and T x (crystallization temperature) of these (Zr 53Cu 30Ni 9Al 8) 100− x Si x alloys increase with the silicon addition. In addition, both the activation energy of crystallization and the incubation time of isothermal annealing these (Zr 53Cu 30Ni 9Al 8) 100− x Si x amorphous alloys indicate that the (Zr 53Cu 30Ni 9Al 8) 99.25Si 0.75 alloy possesses the best thermal stability in the (Zr 53Cu 30Ni 9Al 8) 100− x Si x alloy system. In parallel, the result of compression test shows that the yield strength increases with the addition of Si content and reaches to a maximum value about 1750 MPa with 3% plastic strain for the (Zr 53Cu 30Ni 9Al 8) 99.25Si 0.75 amorphous alloy.