( School of Materials Science and Engineering，
Hebei University of Technology， Tianjin 300130, China)
摘 要: Sm12.7Fe86.3Nb1合金在不同温度下氢爆（HD）及氢化-歧化-解吸-再复合（HDDR）处理时，100 ℃时可氢化形成Sm2(Fe，Nb)17Hy，随着温度升高氢化速度加快，到400 ℃时单胞体积最大膨胀了3.38%。超过500 ℃时Sm2(Fe，Nb)17Hy+H2→SmHy+α-Fe(Nb)发生歧化，直到900 ℃仍旧存在，故氢爆温度应低于500 ℃。解吸与再复合过程在超过700 ℃时可能以SmHy+α-Fe(Nb)→Sm2(Fe，Nb)17+H2方式进行。在连续的HDDR处理过程中，吸氢-歧化在升温（400 ℃/h）的过程中即已完成，而解吸-再复合在保温时与歧化阶段达到平衡，即SmHy+α-Fe(Nb)Sm2(Fe，Nb)17+H2， 抽真空是使该反应向右进行的主要驱动力。在HDDR过程中破坏试样的原颗粒尺寸会残留较多的软磁α-Fe相而恶化氮化后的磁性能，HDDR后残留的α-Fe相含量均高于退火态的残留量，2次循环后磁粉的矫顽力较高。HDDR使粉末颗粒表面产生裂纹，再复合后的Sm2(Fe，Nb)17颗粒细小均匀，尺寸分布在几十纳米到300 nm之间。
关键字: Sm2(Fe， Nb)17型合金; HDDR; 磁性能; 颗粒形貌
（ School of Materials Science and Engineering，
Hebei University of Technology， Tianjin 300130, China）
Abstract: The hydrogenation-decrepitation (HD) as
well as hydrogenation-disproportionation-desorption-recombination (HDDR) processes for Sm12.7Fe86.3Nb1 alloys were investigated at different temperatures by means of XRD， home-made HDDR equipment and microstructure observations. It shows that the hydrogenation reaction Sm2(Fe， Nb)17+H2→Sm2(Fe， Nb)17Hy can begin from 100 ℃, which is accelerated with increasing temperature. The maximal unit cell volume expansion of 3.38% is found at 400 ℃. The disproportionation reaction Sm2(Fe， Nb)17Hy+H2→SmHy+α-Fe(Nb) begins at 500 ℃ and can continue to 900 ℃. The temperature for HD should be below 500 ℃. The desorption-recombination processes maybe carry out according to the reaction SmHy+α-Fe(Nb)→Sm2-(Fe， Nb)17+H2 above 700 ℃. The hydrogenation-disproportionation processes finish when samples are continuously heated up to 800 ℃ at the heating rate of 400 ℃/h， and the desorption-recombination processes will reach equilibrium with disproportionation process on the basis of SmHy+α-Fe(Nb)Sm2(Fe， Nb)17+H2 and only pumping-vacuum can facilitate the reaction to right. Broken samples on halfway HDDR is detrimental to the magnetic properties because of lots of remained α-Fe phase. The content of α-Fe in HDDR-treated samples is higher than that of annealed samples. Lots of cracks in the particles are found among the HDDR-treated samples， and the size of the recombined Sm2(Fe， Nb)17 particles becomes less than 300 nm.
Key words: Sm2(Fe， Nb)17-type alloys; HDDR; magnetic properties; microstructure of particles
