| 摘要 |
PURPOSE:To obtain the billet product of an Mn-Al-C magnet alloy, whose top end is free from generation of cracks, by hot extruding the Mn-Al-C alloy with use of a metal die having the specified ratio of the diameter to the length of its bearing part. CONSTITUTION:The bearing part 9 of an extruding metal die is formed as a straight bearing having the ratio of its diameter D to its length L being 0.8-3.0. When an Mn-Al-C alloy is hot extruded with use of the metal die, a strong tensile force which would cause generation of cracks at the bearing part 9 is suppressed, so that a billet product free from generation of cracks at its top part can be obtained. Consequently, a yield is enhanced in the production of the Mn-Al-C magnet alloy. |
