还原扩散法制备Sm2Fe17Nx磁粉的研究

研究了还原扩散法制备Sm2Fe17Nx磁粉过程中,还原扩散反应温度和时间对Sm2Fe17合金单相性的影响,以及Sm2Fe17合金渗氮过程中渗氮温度和时间对Sm2Fe17Nx磁粉性能的影响.结果表明当还原扩散反应温度为1423K、反应时间为5小时能得到均相单一的Sm2Fe17合金;在728K温度下渗氮3.5小时后,400目～500目的Sm2Fe17Nx磁粉的各项磁性能达最大值Br=0.8943T,Hc=325.8kA/m,Hcj=420.3kA/m,(BH)max=78.6kJ/m3.     

新型纳米材料LaNi5相贮氢合金的制备与性能

采用超声共沉淀法制备了多孔状稀土合金氧化物前驱体,然后将其与CaH2/H2进行低温还原扩散反应得到LaNi5相贮氢合金粉样品。运用XRD、TEM、SEM等测试手段研究了制备条件对样品的晶相结构和微观形貌的影响。实验发现在相对较低的温度(约700℃)下就可以制得颗粒较小(约20nm),粒径分布均匀、相纯度高的LaNi5合金。PCT曲线测试表明样品吸放氢平台宽度增加,平台倾斜度降低。     

Fabrication of ultrafine Nd-Fe-B powder by a modified reduction-diffusion process

In order to obtain ultrafine Nd-Fe-B powder, a spray-dried precursor was treated by reduction-diffusion (R/D) process.And, unlike the conventional R/D process, calcium reduction that is a crucial step for the formation of Nd2Fe14B was performed without conglomerating the precursor with Ca powder.By adopting this modified process, it is possible to synthesize the hard magnetic Nd2Fe14B at the reaction temperature as low as 850 ℃.The average size of Nd2Fe14B particles that are uniformly distributed in the optimally treated powder was ＜ ＜1 μm.Most Nd2Fe14B particles were enclosed with thin layers of Nd-rich phase.Typical magnetic properties of such powder without eliminating impurity CaO were iHc=～5.9 kOe, Br=～5.5 kG, and (BH)max=～6 MGOe.     

La-Mg-Ni系合金新型合成工艺及La0.67Mg0.33Ni3.0合金微结构的研究（英文）

以含La、Mg、Ni元素的化学试剂为原料,先制得三元复合金属氧化物前驱体;再以优化后的实验参数,进行基于共沉淀及还原扩散法联用工艺制备La0.67Mg0.33Ni3.0合金及其微观结构的研究,并验证新型合成工艺的可行性。结果表明:以共沉淀和还原扩散法制得的合金均为多相结构,其组织和成分趋于均匀化,晶格畸变小;并且合金还原过程比较彻底,合金中含氧量极少,取得了预期的效果;La-Mg-Ni系合金新型合成工艺可行,但还需对该工艺进行再优化。     

还原扩散法制备Sm2Fe17化合物的工艺研究

研究了还原扩散法制备Sm2Fe17化合物工艺中Sm2O3，Ca，CaCl2的配入量对Sm2Fe17合金均相性的影响，并用XRD对产物进行物相分析。结果表明：当反应温度为1423K，反应时间为5h，Sm2O3，Ca，CaCl2的配入量分别为121％，225％，8％时，还原扩散反应比较充分，能得到均相单一的Sm2Fe17化合物。     

Preparation of Sm_2Fe_(17)Alloys in Ca-Sm_2O_3-Fe System

Sm2Fe17alloyisanimportantprecursorforthe preparationofSm2Fe17Nxmagnet.Sincethenitrogen containedSm2Fe17(Sm2Fe17Nx)alloy,asapermanent magnetmaterial,possessesahigherCurietempera ture,largeranisotropyfield,betterresistancetooxi dationandthermalstability,and…     

Sm2Fe17Nx的制备

在研究确定了原材料配比的基础上,采用还原扩散法制备出了 Sm2Fe17合金粉;探讨了反应温度、恒温时间、氮气压力及氮气压力200kPa时温度等因素对氮化反应的影响.当氮气压力为200 kPa、温度为873K、恒温5h时,生成Sm2Fe17N2.874,其氮含量为3.111%.     

Preparation of rare earth-cobalt magnet alloy by reduction-diffusion process

Preparation of rare earth-cobalt alloys by reduction-diffusion (R-D) process is described. The process essentially involves mixing of the rare earth oxide and cobalt/cobalt oxide powders in proper proportion and high temperature reduction of the charge in hydrogen atmosphere, followed by aqueous leaching of the reduced mass to yield the alloy powder. Comparison is made of the magnetic properties of the R-D powder with those of the powder prepared by the direct melting (DM) route and it is observed from the reported values for SmCo₅ that the energy product of the R-D powder (∼ 22 MGOe) is only marginally lower than that of the Directly Melted alloy (∼ 25 MGOe). The paper also includes the results of studies carried out at the Bhabha Atomic Research Centre on the preparation of misch metal-cobalt alloy by the R-D process.     

从稀土储氢合金冶炼废渣中回收稀土镍钴合金的研究

对于稀土储氢合金冶炼废渣粉,采用水热酸溶-还原扩散-电弧熔炼的方法回收稀土氧化物和稀土镍钴合金。废渣粉首先用水热酸溶法分离其中的部分稀土氧化物,得到的合金富集物配加金属钙粒用还原扩散法将其中剩余的稀土氧化物转化为AB5型合金,还原扩散得到的合金粉采用电弧熔炼得到稀土镍钴合金。回收的合金杂质含量低,可作为基础原料用于熔炼AB5型稀土储氢合金,实现了稀土储氢合金冶炼废渣的循环利用。