| 摘要 |
PURPOSE:To manufacture a sintered rare earth magnet excellent in magnetic properties, by carrying out sintering of a press-compacted green compact in a hydrogen-gas atmosphere in a first half of the holding time at a sintering temp. and also in a high-pressure nonoxidizing-gas atmosphere in the second half. CONSTITUTION:A pulverized powder of rare-earth alloy with the desired composition is press-compacted in a die to which magnetic field is applied. The resulting green compact is charged into a pressure sintering furnace, and then is sintered in a reduced-pressure, ordinary-pressure, or pressurized hydrogen-gas atmosphere in the first half of the holding time at the sintering temp. and also in a high- pressure nonoxidizing-gas atmosphere of Ar, etc., in the second half. According to this method, the permanent magnet of rare-earth sintered alloy practically free from grain growth, residual bores, and further disorder of crystal orientation and deformation and excellent in magnetic properties can be obtained. |
