| 摘要 |
PURPOSE:To stably obtain a rare earth based cobalt magnet having a bending resistance force of 10kg/mm<2> or more by making the average grain size 3-6mum and the standard deviation deltan<=2.60. CONSTITUTION:An ingot is coarsely crushed by means of a mechanical means such as a hammer mill of brown mill, and further is finely crushed in a non- oxidizing atmosphere (for example, inactive gas, Ar, N2, or a solvent of toluene or alcohol) to make the average grain size 6mum or less. Next, the grain distribution is adjusted using an atmosphere classifier. In the condition that a rare earth based cobalt is given desired permanent magnet characteristics after it passed the final manufacturing process, a bending resistance force increases when the average grain size is 3-6mum and the standard deviation of the grain distribution deltan<=2.60, and a rare earth based cobalt having a bending resistance force of 10kg/mm<2> or more is obtained. |
