摘要 |
PURPOSE:To obtain a rare earth iron permanent magnet having high performance and low cost by hot-working a cast ingot of specific alloy at specific temperature to make crystal grains fine and orienting the crystal axis in a specific direction to be subjected to a magnetic anisotropy. CONSTITUTION:Alloy which contains 8-30 atomic % of R, 2-28 atomic % of B, 50 atomic % or less of Co, 15 atomic % of Al, 13 atomic % or less of additive element (s) M (one or more of V, Nb, and Ta), the residue of iron and other impurities unavoidable in manufacture is melted and cast. The cast ingot is then hot-worked at 500 deg.C or higher to make crystal grains fine, its crystal axis is oriented in a specific direction to subject the cast alloy to a magnetic anisotropy. Thus, coercive force can be obtained only by a heat treatment without pulverizing the ingot, the hot-working may be conducted only by one stage process, coercive force is increased, and steps can be simplified. |