Near-net Shape Casting of Rare-earth Iron Magnet from Undercooled Melt

过冷熔体近净形铸造稀土铁磁体

基本信息

批准号：
15206081
负责人：
KURIBAYASHI Kazuhiko
金额：
$ 18.47万
依托单位：
Japan Aerospace Exploration Agency
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (A)
财政年份：
2003
资助国家：
日本
起止时间：
2003 至 2005
项目状态：
已结题

项目摘要

Neodymium-iron-boron (Nd-Fe-B) magnets with excellent magnetic properties have been widely used in various applications such as computer devices and acoustic equipment. The superiority of the magnets originates from the Nd_2Fe_<14>B intermetallicphase, which has a large saturation magnetization and a high magnetocrystalline anisotropy field. Because the ferromagnetic Nd_2Fe_<14>B phase is formed via the peritectic reaction between the pro-peritectic γ-Fe phase and the residual liquid, in the casting alloy, the α-Fe phase inevitably remains as a soft-magnetic phase, deteriorating the hard magnetic properties of magnets. In the present experiment, as one of novel techniques to suppress the peritectic reaction, containerless processing has been tried, in which the rapid quenching of the undercooled melt is expected to form the Nd_Fe_<14>B phase free from the α-Fe. The objective of the present study is to explore the possibility of the near-net shape casting of a magnet from the undercoole … More d melt.In 2003, a splat quenching system was built up and the know-how to perform the near-net shape casting was established. In 2004, in order to elucidate the relationship between the microstructure and the undercooling, the drop-tube experiment was carried out. The experimental results show that, in the as-dropped sample, a large amount of the Nd_2Fe_<17>B_x was contained as a metastable phase. In 2005, the phase transformation from the metastable Nd_2Fe_<17>B_x into stable Nd_2Fe_<14>B was precisely investigated. The results show that the diffusive phase transformation from Nd_2Fe_<17>B_x into Nd_2Fe_<14>B was rapid, because the Nd-rich phase retained at the intergranular region enhanced the diffusivity of the solute atom due to its low melting temperature, implying that the combination with the splat quenching system enables the near-net shape casting of a magnet from the undercooled melt. In the sample with relatively large diameter, the Nd_2Fe_<14>B and γ-Fe dual-phase pearlite-like microstructure that was decomposed from the metastable Nd_2Fe_<17>B_x can be expected to be one of the prominent candidates for a magnet with nano-composite microstructures. Less

具有出色磁性特性的neododmim-rion-Boron（ND-FE-B）磁铁已被广泛用于各种应用，例如计算机设备和声学设备。磁铁的优势源自ND_2FE_ <14> B间层间，该法层具有较大的饱和磁化和高磁各向异性场。因为铁磁ND_2FE_ <14> B相是通过牢固的渗透性γ-FE相和残留液体之间的直晶反应形成的，因此在铸造合金中，α-FE相不可避免地保持为软磁相，从而降低了磁铁的硬磁性能。在本实验中，作为抑制凝聚反应的新技术之一，已经尝试了无容器的处理，其中预计底层熔融熔体的快速淬火将形成ND_FE_FE_ <14> B相，使其与α-FE无关。本研究的目的是探索磁铁从口水中近网形铸造的可能性……更多的融化。在2003年，建立了Splat淬火系统，并确定了执行近网状形状铸造的专业知识。在2004年，为了阐明微观结构与底层冷却之间的关系，进行了滴管实验。实验结果表明，在流行的样本中，将大量的ND_2FE_ <17> B_X包含作为亚稳态。在2005年，精确研究了从亚稳态ND_2FE_ <17> B_X到稳定的ND_2FE_ <14> B的相变。 The results show that the different phase transformation from Nd_2Fe_<17>B_x into Nd_2Fe_<14>B was rapid, because the Nd-rich phase retained at the intergranular region enhanced the difficulty of the soluble atom due to its low melting temperature, implying that the combination with the splat quenching system enables the Near-net shape casting of a magnet from the undercooled melt.在具有相对大直径的样品中，ND_2FE_ <14> b和γ-FE双相珠光体样微观结构是从亚稳态ND_2FE_ <17> B_X分解的，可以预计将是具有纳米复合微型结构的磁铁的杰出候选者之一。较少的