Ferromagnetic metal powder excelling in oxidation resistance

Abstract

Abstract PURPOSE: To increase the oxidation resistance of ferromagnetic metal powder, by coating the surface of magnetic metal powder manufactured by reducing the produced ferriferous oxide in alkaline reaction solution, with silicone oil. CONSTITUTION: By adding alkaline agent such as caustic potash and sodium carbonate to aqueous solution of ferrous salt such ferrous sulfate, the pH of aqueous solution is adjusted to alkalinity. Then, ferrous hydroxide or insoluble salt is precipitated and deposited. Blowing gas containing oxygen, it is oxidized to obtain powder of gehtite (α-FeOOH), which is then heated and dehydrated to obtain ferriferous oxide (α-Fe 2 O 3 ). Reducing with hydrogen, the material is changed to metal powder, which is then soaked with toluene solution containing silocone oil. Then heating in nitrogen gas atmosphere, toluene is evaporated, so that a ferromagnetic metal powder having silicone oil coating, excelling in oxidation resistance, may be obtained. COPYRIGHT: (C)1980,JPO&Japio

Inventors

• 👤 Akinari Hayashi
• 👤 Shigeo Hirai
• 👤 Nariyuki Hosoo
• 👤 Akira Miyake

Bibliographic Details