Texture in a ternary Nd16.2Fe78.2B5.6 powder using a modified hydrogenation-disproportionation-desorption-recombination process
Texture in a ternary Nd16.2Fe78.2B5.6 powder using a modified hydrogenation-disproportionation-desorption-recombination process
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DOI：
10.1016/s0304-8853(99)00702-7
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发表时间：
2000-02
影响因子：
2.7
通讯作者：
O. Gutfleisch;B. Gebel;N. Mattern
中科院分区：
文献类型：
--
作者：
O. Gutfleisch;B. Gebel;N. Mattern
本文对Nd_（16.2）Fe_（78.2）B_（5.6）合金进行了由（i）固态氢化和（ii）氢分压下的缓慢复合组成的氢化-氢化-解吸-复合（HDDR）过程。扫描电子显微镜显示，在900°C下氢化15分钟后观察到的NdH 2 ± x和Fe的最初细棒状结构随着延长的退火转变为颗粒状形态。同时，存在细分散的直径为10- 50 nm的四方形Fe_3B颗粒。XRD研究表明，该亚稳的Fe 3B相在进一步退火时转变为Fe 2B和Fe。短的固相化时间导致复合后的各向异性程度更高，而长的退火时间和常规处理导致各向同性材料。结果表明，固态时效后形成的中间相四方相Fe_3B是HDDR处理三元NdFeB型合金织构形成的关键。
A modified hydrogenation–disproportionation desorption-recombination (HDDR) process consisting of (i) solid disproportionation and (ii) slow recombination under partial hydrogen pressure has been applied to a Nd16.2Fe78.2B5.6alloy. Scanning electron microscopy shows that an initially fine rod-like structure of NdH2±xand Fe observed after 15min of hydrogenation at 900°C is transformed into a granular morphology with prolonged annealing. Simultaneously, finely dispersed tetragonal Fe3B particles of 10–50nm diameter exist. XRD studies show that this metastable Fe3B phase is transformed to Fe2B and Fe on further annealing. Short solid-disproportionation times result in a higher degree of anisotropy after recombination, whereas long annealing times and conventional processing lead to isotropic material. It is concluded that the formation of the intermediate tetragonal Fe3B phase after solid disproportionation is pivotal for the inducement of texture in HDDR processed ternary NdFeB-type alloys.