ABSTRACT
The raw materials rods of four kinds of shape memory alloy, TiNi, NiAl and CuNi system alloys were prepared by arc melting process. These raw material rods were chucked by the grip connected with a rotating motor that was fixed on the wall at the upper side of the chamber.. By moving down and supplying the raw material rod (block) continuously from the upper side into the high frequency Cu spiral coil, the melt finally flows down within the coil after the balance between the melt's weight and electro-magnetic Lorentz floating force is broken. The capacity of the high frequency (180kHz) alternative current of this equipment is 200V, 50A (i.e. lOkW). Its critical condition depends on the kind of metal »mainly its specific weight, viscosity, surface tension etc.of raw material. By changing the spiral coil shape to conical type for making the flow of melt more slender and finer as much as possible , it became possible to produce the continuous thin plate of TiNi alloy whose thickness was 60-300 jjl m, width 10-20mm and length 150-200mm. An example of the produced Ti-Ni50.2(at%) thin plate by twin roll whose rotating speed was 28 m /sec in Ar atmosphere of the chamber is shown in Fig.7. It shines and has metallic laster. It does not exist the oxidation on the surface,however, the edges of the TiNi thin plate are wavy due to unsteady flow as well as the instability of the contact between melted flow and rotating rolls e tc ..
