Thermal and mechanical properties of the Zr_(53)Cu_(30)Ni_9Al_8 based bulk metallic glass microalloyed with silicon

摘要

The amorphous alloy rods of (Zr_(53)Cu_(30)Ni_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_(53)Cu_(30)Ni_9Al_8)_(100-x)Si_x alloy rods exhibit a typical amorphous diffraction pattern with only a broad maximum around 29 around 40 degree. Both T_g (glass transition temperature) and T_x (crystallization temperature) of these (Zr_(53)Cu_(30)Ni_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_(53)Cu_(30)Ni_9Al_8)_(100-x)Si_x amorphous alloys indicate that the (Zr_(53)Cu_(30)Ni_9Al_8)_(99.25)Si__(0.75) alloy possesses the best thermal stability in the (Zr_(53)Cu_(30)Ni_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 percent plastic strain for the (Zr_(53)Cu_(30)Ni_9Al_8)_(99.25)Si__(0.75) amorphous alloy.