| 摘要 |
PURPOSE:To enable to cut down the cost of production of the titled magnet by a method wherein Sm2O3 powder and Co powder are placed in a retort together with the Ca of specific grain diameter, and they are reduced by heating under the specific conditions. CONSTITUTION:Sm2O3 powder is used for the Sm which is a component of the Sm-Co magnet, Co powder is used for the Co of the magnet, and Ca grains of 0.5-10mm in diameter are used as the reducing agent of the Sm2O3. If the grain diameter of Ca is less than 0.5mm, the rate at which the Ca is formed into CaO before placing it into the retort is increased, and if the grain diameter of the Ca exceeds 10mm, the reaction efficiency is lowered. The Sm2O3 powder, the Co powder and the Ca grains of the prescribed quantity are mixed, placed into the retort, and reduced by heating. At this time, inside the retort is heated up to 1,000 deg.C or above in an Ar atmosphere. The period of processing of the fine Ca grains is to be made longer when the temperature is less than 1,000 deg.C. After the reducing process is finished, the powder is washed with water and dried up as occasion demands, and the CaO is removed. As low-priced Sm2O3 is used and the reducing efficiency is improved using the Ca grains of specific grain diameter, the magnet can be manufactured at low cost. |
