Anisotropic, eutectically solidifying more phases alloy and method for their preparation

摘要

960,266. Zone-melting alloys. UNITED AIRCRAFT CORPORATION. July 6, 1961 [Sept. 30, 1960], No. 24452/61. Heading B1S. An alloy having an elongated grain structure comprising plates (Fig. 9a) or rods of eutectic composition is produced by passing the alloy in a graphite crucible 6, Fig. 8, downwards through a silica tube 2 having an induction heating coil 4 and a cooler 22 such that the ratio (G/R) of the thermal gradient at the crystallization front to the solidification rate is 0À1-1000 ‹C./cmSP2/SP./hr. The upper surface of the alloy is protected by an inert gas fed through a tube 14 and the temperature is measured by a thermocouple 10. The grains may be 0À02- 10 microns thick. The longitudinal direction of the grains may deviate from the direction of passage by up to 30 degrees. A number of alloys are specified. If the alloy is of overall non-eutectic composition, the product contains interspersed large crystals. In the example, the thermal gradient is 172 ‹C./ cm. and the rate of solidification is 6À7 cm./hr. (giving a G/R of 25À6).