METHOD OF FORMING MAGNETOSTRICTIVE RODS FROM RARE EARTH-IRON ALLOYS

• Main Author: MCMASTERS, O. DALE
• Format: Patent
• Language: English
• Published: 02.11.1989
• Edition: 4
• Subjects: AFTER-TREATMENT OF SINGLE CRYSTALS OR A HOMOGENEOUSPOLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; ALLOYS; APPARATUS THEREFOR; CHEMISTRY; CRYSTAL GROWTH; ELECTRICITY; FERROUS OR NON-FERROUS ALLOYS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUSMETALS OR ALLOYS; MAKING METAL MALLEABLE BY DECARBURISATION, TEMPERING OR OTHERTREATMENTS; METALLURGY; METALLURGY OF IRON; MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; PRODUCTION OF A HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITHDEFINED STRUCTURE; REFINING BY ZONE-MELTING OF MATERIAL; SINGLE CRYSTALS OR HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITHDEFINED STRUCTURE; SINGLE-CRYSTAL-GROWTH; TREATMENT OF ALLOYS OR NON-FERROUS METALS; UNIDIRECTIONAL SOLIDIFICATION OF EUTECTIC MATERIAL ORUNIDIRECTIONAL DEMIXING OF EUTECTOID MATERIAL

Rods of magnetrostructive alloys of iron with rare earth elements are formed by flowing a body of rare earth-iron alloy in a crucible enclosed in a chamber maintained under an inert gas atmosphere, forcing such molten rare-earth-iron alloy into a hollow mold tube of refractory material positioned with its lower end portion within the molten body by means of a pressure differential between the chamber and mold tube and maintaining a portion of the molten alloy in the crucible extending to a level above the lower end of the mold tube so that solid particles of higher melting impurities present in the alloy collect at the surface of the molten body and remain within the crucible as the rod is formed in the mold tube.