Production of Al-Based Amorphous Alloy Wires with High Tensile Strength by a Melt Extraction Method

Al-based amorphous alloy wires with composition Al₈₅ Ni₁₀ Ce₅ were produced by a melt extraction method using a copper wheel with a steep edge. The wire has a circular cross section and no appreciable trace resulting from the use of copper wheel is seen on the outer surface. The wire diameter is in the range of 40 to 70 μm and tends to decrease with increasing rotation speed of the wheel. The onset temperature of crystallization, the glass transition temperature and the heat of crystallization are 531 K, 546 K and 0.37 kJ/mol, respectively, for the wire with a diameter of about 70 μm, in agreement with those for the melt-spun amorphous ribbon with a thickness of about 15 μm. The wires have good bending ductility and a high tensile strength of 950 MPa. The maximum wire diameter of 70 pm is nearly the same as the maximum ribbon thickness for the formation of ductile amorphous alloy with the same composition by the conventional melt spinning method. The high cooling rate for the present process is accomplished presumably because the supercooled liquid with a small volume and a large outer surface area to volume ratio is solidified homogeneously without contact of other substances.