Cast structure and mechanical properties of Zr–Cu–Ni–Al bulk glassy alloys

Homogeneous melting without any nuclei was performed using the cold copper nozzle arc casting furnace and ladle arc-melt type furnace. Casting of a bulk glassy alloy can be achieved by using a copper nozzle arc casting furnace, which eliminates nucleation site (cold spot) for crystallization. Besides, the pouring molten alloy was melted homogeneously by arc heating before casting into the mold, similar to a pseudo float melting state. To produce a bulk glassy alloy sheet, a combination of the ladle arc-melt type furnace and squeeze cast method was used. Using this method, we succeeded in producing Zr50Cu30Ni10Al10 bulk glassy alloys in a rod shape by the former method and in a sheet form by the later method. Tensile strength of the Zr50Cu30Ni10Al10 bulk glassy alloy sheet is about 1900 MPa and the plasticity of the alloy at room temperature is significantly improved by cold rolling.