METASTABLE EXTENSION OF SOLID SOLUBILITY OF CERTAIN LIGHT RARE-EARTH METALS IN Ag

以点阵参数法测定了轻稀土金属La,Ce,Pr,Nd和Gd于熔体淬火条件下在Ag中固溶度的扩展.在10~5—10~6 K/s冷却速度下,它们在Ag中的亚稳极限固溶度分别为1.0,1.5,2.5,3.0和6.0at.-％。这些合金的固溶度扩展与镧系收缩成正比,并且符合作者早先对α(A)-A_mB_n型共晶系所提出的扩展机理和规律,还进一步讨论了平衡态固溶度的规律。     

METASTABLE EXTENSION OF SOLID SOLUBILITY OF CERTAIN SIMPLE METALS OR METALLOIDS IN Ag

用点阵参数法研究了在熔体淬火条件下若干简单金属与类金属在Ag中固溶度的亚稳扩展。发现与Ag发生一系列包晶反应的二元合金的固溶度扩展符合电子浓度规律,并结合相图特征讨论了包晶系固溶度扩展的规律。简单共晶合金的固溶度扩展并不满足电子浓度规律,用Miedema理论解释了Si在Ag中固溶度低的原因。     

METASTABLE EXTENSION OF SOLID SOLUBILITY OF RARE-EARTH ELEMENTS IN Al

The splat folis of Al-RE(RE=Y,La,Ce,Pr,Nd,Sm,Eu,Gd,Tb,Dy,Er and Yb)binary alloys of 0.04—0.06 mm thickness were made by are-melting and hammer-anviltechnique,the.cooling rate is in 10~6 K/s order of magnitude.The metastable extendedsolid solubilities of these RE elements have been evaluated by measurements of the latticespacings of the rapidly solidified(RS)Al-RE alloys,they are 0.4,0.15,0.21,0.21,0.3,0.5,0.1,0.6,0.65,0.7,0.75,0.2 at.-% for above individual RE clements,respectively.Thesecondary phase in RS Al-RE alloys were identified to be Al_4RE for alloys containinglight RE and Eu elements and Al_3 RE for alloys containing heavy RE and Y elements.Some factors influencing the extension of solid solubility of Al-RE alloy were discussed.     

稀土元素在Al中固溶度亚稳扩展研究

采用锤—砧技术制备了厚0.04—0.06mm快速凝固Al—RE(RE=Y,La,Ce,Pr,Nd,Sm,Eu,Gd,Tb,Dy,Er,Yb)合金箔试样,冷却速度达10~6K/s,用点阵参数法测得上述稀土元素在Al中亚稳扩展固溶度分别为0.4,0.15,0.21,0.21,0.3,0.5,0.1,0.6,0.65,0.7,0.75和0.2at.—%测定了Al—轻稀土(包括Eu)系中第二相是Al_4RE;Al—重稀土(包括Y)系中第二相是Al_3RE,原子尺寸因素是控制RE在Al中固溶度亚稳扩展的主要因素。     

机械合金化扩展Fe—Cu系固溶范围

机械合金化法可使室温下不互溶体系Fe_(1-x)Cu_x形成过饱和固溶体。X射线衍射实验表明;当x≤0.15时为具有Fe的bcc结构固溶体;当x≥0.40时具有Cu的fcc结构固溶体;当0.15相似文献   

EXTENSION OF SOLID SOLUBILITY BY MECHANICAL ALLOYING IN Fe-Cu SYSTEM

Mechanical alloying was employed to produce super—saturated solution of Fe_1-xCu_x ,whichis virtually immiscible under an equilibrium condition at ambient temperature.XRD resultsshow that the solutions formed in the concentration ranges of x≤O.15 and x≥0.40 are of beestructure of x-Fe and fee structure of Cu,respectively.For the region in between(0.15相似文献   

机械合金化诱导Fe—Cu系固溶度的扩展

X射线衍射(XRD)表明室温下几乎不固溶的Fe—Cu系经5h球磨后可形成亚稳过饱和固溶体.对于Fe_(1-x)Cu_x,当0≤x≤0.10时形成单一的bcc相,x≥0.30时形成单一的fcc相,0.10相似文献   

共晶系固溶度亚稳扩展与相图的关系

讨论了共晶系合金固溶度亚稳扩展与相图的关系.提出了固溶度亚稳扩展程度的判据:当参数J>10(J=(C_m-C_(eu))/(C_(eu)-C_(eq)),C_m,C_(eu)和C_(eq)分别为第二相浓度、共晶浓度和平衡固溶度)时,合金获过共晶扩展,亚稳极限固溶度C_(eq)~s大于共晶浓度,当J≤10,合金只能有亚共晶扩展,C_(eq)~s相似文献   

RELATIONSHIP BETWEEN METASTABLE EXTENSION OF SOLID SOLUBITY OF EUTECTIC SYSTEMS AND PHASE DIAGRAM

A criterion of the metastable extension of solid solubility was proposed.When the eutecticconcentration arm ratio parameter of an alloy,J>10,the hypereutectic extension and themetastable solid solubility limit beyond eutectic concentration may be obtained.When J≤10,the hypoeutectic extension may be obtained.The extension parameter,C_(eq)~s/C_(cu),is directlyproportional to the parameter J.Thus,it seems easy to predict the tendency of the solid solu-hility extension under rapid solidification on the basis of the eutectic phase diagram.     

VACUUM VAPORIZATION OF CERTAIN ELEMENTS IN CARBON-SATURATED IRON MELT

在ZG-10型真空感应炉内研究了S,Mn、Cu、Si、P的挥发特性。找到了在时间、温度、真空度、比表面积等各种影响因素下诸元素的挥发次序及其特征。实验发现,在1330℃时,S、Mn、Cu的挥发率出现极大值。     

金属亚稳态孔蚀行为的电化学研究

综述了国内外近期在亚稳态孔蚀行为的研究方法,亚稳态小孔形核、生长的统计规律 ,亚稳态蚀孔生长和再钝化过程的机制及控制因素,亚稳态蚀孔向稳定蚀孔转变的临界条件等方面的 研究进展,并对进一步的研究作出了展望。     

铜镍合金海水腐蚀的表面与界面特征研究

采用金相（ＯＭ）、俄歇（ＡＥＳ）、扫描电镜（ＳＥＭ）及透射电镜（ＴＥＭ）等技 术手段对实海暴露试样进行探测分析,揭示了表面膜缺陷（如碳膜）、晶界缺陷（晶界析出物）等加速该 合金腐蚀进程的试验现象和内在根据,特别指出影响该合金海水腐蚀产物膜稳定性的主要因素,分析了其中的沿晶扩散及应变诱生调峰分解与沿晶腐蚀、沿晶脆断的相互关系。     

过渡金属二元连续固溶系液相线、固相线的计算机预报

用过渡金属元素的原子半径、价电子数、主量子数、d电子数和f电子数等为人工神经网络的输入值,用已知的二元连续固溶系相图液相线和固相线的实测数据为输出值训练人工神经网络．并用其对未知二元连续固溶系的液相线和固相线进行计算机预报．若干二元系计算结果与实测结果相当接近．     

过渡金属二元连续固熔系液相线,固相线的计算机预报

用过滤金属元素的原子半径、价电子数、主量子数、ｄ电子数ｆ电子数等为人工神经网络的输入值,用已知的二元连续固溶系要图液相线和固相线的实测数据为输出值训练人工神经网络,并用其对未知二元连续固溶系的液相线和因相线进行计算机预报,若干二元系计算结果与实测结果相当接近。     

金属在固液两相流体中的冲刷腐蚀及其防护

金属在液固两相流中因受冲刷和腐蚀的共同作用,服役寿命受到严重影响。对冲刷腐蚀的影响因素、损伤机理进行了分析,总结了控制冲刷腐蚀的防护措施,并展望了冲蚀研究的发展趋势。     

MICROSTRUCTURE AND EXTENDED SOLID SOLUBILITY OF Tb IN RAPIDLY SOLIDIFIED Ag-Tb ALLOY

The 0,05—0.08 mm thick splat foils of Ag-Tb alloy,containing Tb up to 10 at.-%,were made by the hammer-anvil technique.The cooling rate was in order of 10~6 K/s.The metastable extension of solid solubility of Tb in the alloy was measured to be up to 5 at.-% by lattice parameter method.The secondary phase in metastable eutectic structure was identi- fied as Ag_3Tb from diffraction pattern.The microstructure and micro-defect in as-quenched Ag-Tb splat foil were also observed.     

A CRITERION OF THE FORMATION OF AMORPHOUS STATE BY MELT QUENCHING

本文提出了合金熔体淬火形成非晶态的新判据:I/ΔS<0.032,I-0.1/ΔS>0.0044,其中I=1-T_m/(?)_m,△S=1/100C_B((?)_m-T_m)。T_m是合金的熔点,(?)_m是组元加权平均熔点,C_B是合金溶质B的at％。新判据考虑了合金成分和中间相的影响,提高了准确性。在全部所讨论的127个合金中,只有一个明显例外。此外还讨论了形成非晶态合金的浓度分布和相图特征。     

ELECTRONIC STATES AND HYDROGEN EMBRITTLEMENT IN TRANSITION METALS

1.IntroductionHydrogenembrittlementinmetalshasbeenstudiedforal0ngtimesincetherole0fdissolvedhydrogenindef0rmationandfractureinsteelmaterialswasrecognized.Thereexistanumber0fexperimentaldata0nhydrogeriembrittlementindifferelltmaterials.Anumber0fstudies0nthissllbjecthavebeenrep0rtedandreviewedtodataintheliterature.However,themechanismofhydrogenembrittlementinmetalsisnotclearyetfromamicr0sc0picpointofview.lnthispaperwepointoutsomeproblemsofthemechanismofhydrogenembrittlementinmetalsanddevel0panel…     

Tb在快速凝固Ag合金中固溶度扩展

采用电弧熔化快速锤砧急冷技术制备含Tb直到10at.-%的Ag-Tb合金箔,厚度0.05—0.08mm,其冷却速度为10~6K/s数量级,采用晶格参数法确定Tb在快速凝固Ag-Tb合金中亚稳扩展固溶度可达到5at-%,确定亚稳共晶中的第二相为Ag_3Tb,观察了快凝Ag-Tb合金的显微结构与缺陷。