Edmund Bühler Melt-Spinner SCCopyright: © Carl Brunn
By means of the melt spinner, metallic ribbons with a thickness of d ≈ 50 μm can be manufactured. For this purpose, the metallic alloy is melted by inductions in a silica glass or boron nitride crucible. This is done under a vacuum or argon atmosphere. Thus, oxidation of the metallic alloy is prevented. The operating temperatures of the crucibles are T ≤ 1,200 °C for the case of silica glass and T ≤ 1,600 °C for the boron nitride crucible. The working temperature is detected by means of a pyrometer. In the next step, the melt is pressed out of the crucible onto a rotating copper wheel using argon. As the melt impinges on the copper wheel, the melt is transferred into ribbon and solidifies with cooling rates of Ṫ ≤ 106 K/s.The parameters such as the rotational speed of the copper wheel, the temperature of the melt, the argon overpressure and the distance between the crucible and the copper wheel influence the thickness and the morphology of the ribbon. In addition to the mentioned parameters, the chemical composition of the alloy is decisive for the morphology of the ribbons. According to the Figure, the morphology can be amorphous (top) or crystalline (bottom).