Development of manufacturing method of permanent magnet wires by using in-rotating liquid spinning process

我们再次对NdFeB合金线材进行了研究，并尝试生产了不含铁磁元素的MnBi型永磁线材。在本研究中，我们控制了尽可能低的冷却液温度和DRAM的转速。此外，我们还研究了添加第四元素抑制晶体生长过程的可能性。当DRAM的转速为6.8-7.3m/S，冷却温度为3度时，我们成功地生产出了NdFeB线材。然而，它的矫直力约为500Oe。我们还选择了Ti(2-6wt%)作为第四元素，其矫顽力提高了约1.3倍，但热处理(650℃，1h)后的矫顽力并没有达到我们的目标值。薄带的矫顽力大于5kOe，与文献报道的结果一致。所生产的MnBi线脆性大，磁性能较软。

We mainly investigated NdFeB alloy wires again and newly tried to produce a MnBi permanent magnet wire, which does not include ferromagnetic elements. In this study, we controlled the coolant temperature as lower as possible and the rotational speed of dram. Also we examined possibility to inhibit crystal growth process by adding the 4th element. We successfully produced a NdFeB wire when the revolution speed of dram was 6.8-7.3 m/s at 3 degrees of the coolant temperature. However its coercive force was around 500 Oe. We also selected Ti (2-6wt%) as the 4th element and the coercive force was improved about 1.3 times, however the coercive force after heat-treatment (650 degrees for 1 hour) had not reached our object value.As for the MnBi permanent magnet wire, we made a ribbon firstly. The coercive force of the ribbon was over 5 kOe, which was in good agreement with references. The produced MnBi wire was very fragile and the magnetic property was soft.