Sm_(12.7)Fe_(86.3)Nb_1合金的氢处理  

Hydrogen treatment on Sm_(12.7)Fe_(86.3)Nb_1 alloys

作　　者：孙继兵[1] 崔春翔[1] 张颖[1] 王如[1] 吴瑞国[1] 梁志梅[1] 

机构地区：[1]河北工业大学材料学院,天津300130

出　　处：《中国有色金属学报》2004年第9期1590-1598,共9页The Chinese Journal of Nonferrous Metals

基　　金：国家自然科学基金资助项目(50271024);河北省自然科学基金资助项目(501013)

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300nm之间。The hydrogenation-decrepitation (HD) as well as hydrogenation-disproportionation-desorption-recombination (HDDR) processes for Sm_12.7Fe_86.3Nb_1 alloys were investigated at different temperatures by means of XRD,　 home-made HDDR equipment and microstructure observations. It shows that the hydrogenation reaction Sm_2(Fe,　Nb)_17+H_2→Sm_2(Fe,　Nb)_17H_y 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 Sm_2(Fe,　Nb)_17H_y+H_2→SmH_y+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 SmH_y+α-Fe(Nb)→Sm_2-(Fe,　Nb)_17+H_2 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 SmH_y+α-Fe(Nb)Sm_2(Fe,　Nb)_17+H_2 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 Sm_2(Fe,　Nb)_17 particles becomes less than 300 nm.

关 键 词：Sm2(Fe Nb)17型合金 HDDR 磁性能 颗粒形貌 

分 类 号：TF132.272[冶金工程—冶金物理化学] TM271.3[一般工业技术—材料科学与工程]