Boundary trend of α1/(α1 +α2) phase region at lower Cu side in Al-Zn-Cu system

The range of miscibility gap above 300 ℃ at low Cu side in Al-Cu-Zn ternary system was obtained by EPMA of the designed alloys and diffusion-couples treated for equilibrium. The results about the boundary trend of the α1 / (α1 α2 ) phase region was obtained. The α1 / (α1 α2 ) boundary moves towards the lower Zn side with the increase of Cu content. The results are opposite to traditional phase diagrams obtained by experiments, but consistent with recent thermodynamic calculations.     

Cu对Al-Zn系a1／（a1＋a2）边界走向的影响

对平衡处理(300℃～340℃)后的Al-Zn及Al-Zn加Cu合金a1相成分进行了电子探针微区分析。确定了Cu对a1 a2溶解度间隙形状，即a1/(a1 a2)边界走向的影响。该边界随着Cu含量的增加，向低Zn侧偏移，而不是此前所确定的向高Zn侧偏移。这一结果支持近年的热力学计算结果，溶解度间隙呈“隧道形”，而不支持根据实测相图推测的“钟罩形”。     

再结晶退火对Ni_（47）Ti_（44）Nb_9合金冷轧板相组成及板材织构的影响

采用Ｘ射线衍射术和ＯＤＦ研究了再结晶退火对Ｎｉ４７Ｔｉ４４Ｎｂ９合金冷轧板相组成和织构的影响。结果表明，冷轧板材的相组成为Ｂ２＋β－Ｎｂ＋Ｂ１９＇；织构类型为面织构｛００１｝ｐ＋｛１１０｝ｐ再结晶退火期间，马氏体相Ｂ１９＇逆转变为母相Ｂ２，合金的相组成为：Ｂ２十β－Ｎｂ，而再结晶织构为：｛００１｝＜１１０＞ｐ。     

钢中碳活度对碳化物覆层扩散处理动力学的影响

本研究选用了几种在扩散温度下为单相奥氏体的钢种,在同样的处理条件下测定了碳化物层的生长速度,并计算了各钢在处理温度下的奥氏体碳活度。结果表明,碳化物层的厚度与奥氏体中的碳活度的平方根成线性关系,从而证明了碳化物层生长动力学的控制因素是钢基体中的碳活度而不是碳浓度。     

Ti－Al－Si三元系中叶α（α_2）／γ相平衡的研究

利用电子探针微区成分分析测定了Ｔｉ－Ａｌ－Ｓｉ系低Ｓｉ部分的α（α２）／γ相平衡关系，并进行了热力学分析．结果表明，相对于Ｔｉ－Ａｌ二元系，Ｓｉ的加入使α（α２）／（α（α２）＋γ）相界线向富Ｔｉ方向移动，而（α（α２）＋γ）／γ相界线变化不大；Ｓｉ具有细化片层组织的作用，井使其粗化困难；Ｓｉ在α（α２）相中的溶解度大于γ相，为α相稳定化元素；Ｓｉ含量为１．０％（原子分数）时，组织中出现第三相Ｔｉ５Ｓｉ３．     

Al-Zn(Cu)合金的相变和Al-Zn-Cu系相图

Al-Zn-Cusystemistheimportantbasisfor practicalAlalloysandZnalloys[1].Amiscibility gapofthefccphaseexistsabove277℃inthe Al Znsystem[2].Thealloywhosecompositionis atthetopofthemiscibilitygapiscalledsym metricalalloyAlZn.Thisalloyhasmanytypical properties.Theimportantoneisthatthespi nodaldecompositioneasilytakesplaceinit.In ordertoavoidthedecomposition,Cuhasbeen added,whichiseffective.Additionof2%Cu molefractioncoulddelaythespinodaldecompo sitionfortwogrades[3,4].AlZn 2Cuisanalloy which…     

STUDY ON α/γ PHASE EQUILIBRIUM IN Ti-Al-Cr-Fe QUARTERNARY SYSTEM

设计了一种简单的扩散偶,用扩散偶－电子探针法,测定了１２００和１２５０℃Ｔｉ－Ａｌ－Ｃｅ－Ｆｅ四元系中Ｘｃｒ≤４％和ＸＦｅ≤１％范围内的α／γ相平衡关系和相平衡成分,绘出了四元系的局部等温正方形,结果表明,在Ｔｉ－Ａｌ－Ｃｒ－Ｆｅ四元系中,Ｃｒ有提高Ｆｅ在α相中的溶解度的作用,Ｆｅ亦有提高Ｃｒ在α相中的溶解度的趋势。     

高淬透性材料淬透性能测定方法的研究

本研究提出了一种研究高淬透性材料淬透性的新方法,一些无法用标准 Jominy方法测定淬透性的材料,可用本法简单地实现淬透性的比较。实验表明:本方法冷速分布合理,测量精度高,方法简便易行。本文用新的试验方法给出了国产5CrNiMo和西德、日本同类钢材等五种不同成分和冶炼工艺的高淬透性钢的半冷时间与淬火硬度的关系曲线,使这些钢材之间淬透性微小差别的比较得以实现。     

AN ISOBAR-ISOTHERMAL PHASE DIAGRAM OF THE Nd-Fe-B SYSTEM AT ATMOSPHERIC PRESSURE AND 1000℃

An isothermal section of Nd-Fe-B system at 1000℃ and the phase equilibrium relationship in Fe-Ndand Nd-B binary systems were investigated with diffusion couple by means of metallographic observation,electron microprobe analysis and X-ray diffraction.It was shown that there are three stable ternary com-pounds,Nd_2Fe_(14)B,Nd_2Fe_7B_6 and Nd_9Fe_3B_8 in Nd-Fe-B system at 1000℃.None of these phases has solu-bility,that is,they are exactly stoichiometric phases.On the other hand,there exist rather wide two-phaseregions between Nd_2Fe_7B_6 and liquid as well as between Nd_9Fe_3B_8 and liquid.It was identified that there isno NdFe_2 compound in the system under atmospheric pressure.