稀土元素Sm对AM60镁合金显微组织和耐腐蚀性能的影响

采用静态失重法、扫描电子镜及能谱分析、电化学测试法等方法研究了稀土元素Sm(0~0.9%)对AM60镁合金的铸态组织和耐腐蚀性的影响。结果表明:微量稀土元素Sm可细化AM60镁合金中β-Mg17Al12相,合金中的β-Mg17Al12相由粗大、连续树枝状分布逐渐转变为细小、弥散的颗粒状均匀分布。同时,合金中生成了大量弥散分布的富Sm的稀土相。这些富Sm的稀土相使合金的耐腐蚀性得到显著提高,当稀土Sm含量为0.6%时,合金腐蚀速率为0.6mg·cm-2·d-1,仅为基体合金的37%。随AM60镁合金中稀土元素Sm含量的增加,合金腐蚀电位逐渐升高,腐蚀电流减小。     

光度法二元稀土混合物中钕、钐的同时测定

本文研究了钕、钐与半二甲酚橙及氯化十六烷基吡啶配合物的吸收光谱和导数吸收光谱。发现钕、钐配合物的最大吸收波长均位于６０６ｎｍ，二者的吸光度具有良好的加合性。钕配合物的４ｆ电子跃迁峰在５８５ｎｍ有显著增强，用四阶导数光谱测定钕。基于此，发展了一个光度法同时测定钕、钐的新方法，对合成样进行分析，结果令人满意。     

二碘化钐在分子内环化反应中的应用

综述了二碘化钐在分子内环化反应中的应用。     

（Sm，Er）-α-Sialon陶瓷材料显微结构与性能研究

采用热压烧结方法制备了Ln1.0／3Si9．3Al2.7O1．7N14．3的Ln-α-Sialon（Ln=Sm和Er）陶瓷。研究了不同Sm：Er摩尔比和外加2．5％（质量分数，下同）的相同稀土氧化物对Ln-α-Sialon陶瓷显微结构和力学性能的影响，并借助XRD、SEM、EDS对样品的物相、显微结构进行了表征。结果表明：随着Sm：Er摩尔比值的减小，α-Sialon晶粒形貌逐渐由等轴状变成长柱状，显微硬度逐渐变大，最高值为19．5GPa，抗折强度和断裂韧性逐渐降低。在原始配方的基础上外加2．5％的同种稀土氧化物能进一步促进长柱状α-Sialon晶粒的生长，力学性能得到不同程度的提高。     

钐(Ⅲ)-1,3-二苯基-4-苯甲酰基-5-吡唑酮配合物的合成及其荧光性质

合成了钐（Ⅲ）的1，3－二苯基－4－苯甲酰基－5－吡唑酮（DPBZP）的二元配合物Sm(DPBZP)3.2H2O和三元配合物Sm(DPBZP)3.Phen(Phen为邻菲罗啉），通过化学分析和元素分析确定了配合物的组成，通过FT－IR谱对配合物进行了表征，配合物的荧光光谱表明，配合物发射Sm（Ⅲ）的特征荧光，1，3－二苯基－4－苯甲酰基－5－吡唑酮的三重态能级与Sm^3 最低激发态^4G5/2能级具有良好匹配；第二配体Phen具有荧光增强作用。     

Effect of rare earth samarium addition on the kinetics of precipitation in AI-Cu-Mn casting alloy

The mechanical properties of Al-Cu-Mn casting alloy mainly depend on the morphology, distribution, size, and number ofθ′（Al2Cu） precipitates. In this study, we have analyzed the effect of rare earth samarium （Sm） addition on the kinetics of precipitation in the Al-Cu-Mn casting alloy by using differential scanning calorimetry （DSC） and high-resolution transmission electron microscopy. Thermal ef-fect peaks that are attributed to the formation and the dissolution of Guinier-Preston （GP） zone andθ′phase were identified from the DSC curves. The activation energy ofθ′formation was calculated by using both the Kissinger method and the analytical model, and the corre-sponding results were compared. Results suggest that the activation energy ofθ′formation in Al-Cu-Mn alloy is dramatically higher than that in Al-Cu-Mn-Sm alloy. Accordingly, it is concluded that the addition of rare earth Sm decreases the activation energy ofθ′formation and promotes the formation ofθ′precipitates.     

Thermochemistry on coordination behavior of samaric chloride hydrate with diethylammonium diethyldithiocarbamate

The complex of samaric chloride lower hydrate-with diethylammonium diethyldithiocarbamate (D-DDC) was synthesized conveniently in absolute alcohol and dry N2 atmosphere. The title complex was identified as Et2NH2[Sm(S2CNEt2)4] by chemical and elemental analyses, the bonding characteristics of which was characterized by IR.T he enthalpies of solution of samaric chloride hydrate and D-DDC in absolute alcohol at 298.15 K and the enthalpies change of liquid-phase reaction of formation for Et2NH2[Sm(S2CNEt2)4] at different temperatures were determined by microcalorimetry. On the basis of experimental and calculated results, three thermodynamic parameters (the activation enthalpy, the activation entropy, and the activation free energy), the rate constant, and three kinetic parameters (the apparent activation energy, the pre-exponential constant, and the reaction order) of liquid phase reaction of formation were obtained. The enthalpy change of the solid-phase title reaction at 298.15 K was calculated by a thermochemical cycle.     

Sm2Fe17合金的氮化处理及磁畴观察

在不同的温度和时间下对Ｓｍ２Ｆｅ１７合金进行氮化处理，利用Ｋｅｒｒ显微镜和透射电镜（ＴＥＭ）观察磁畴及氮化层，氮化处理之前在Ｓｍ２Ｆｅ１７合金中观察不到磁畴，但在氮化处理后可观察到许多磁畴及裂纹。氮化层的厚度约１０μｍ。通过扫描电镜（ＳＥＭ），俄歇电镜（ＳＡＭ）以及电子探针微区分析（ＥＰＭＡ）对合金进行了定性，半定性和定量的成分分析。