铝,镁,稀土对低铝锌合金镀层性能的影响

利用正交试验探讨了锌铝稀土镁合金配制的最佳工艺,研究了铝、镁、稀土对镀层上锌量及耐蚀性的影响。同时比较了几种合金耐蚀性的差别。进而提出了一种新型的热镀锌合金。     

冷却速度对稀土锌合金凝固组织和性能的影响

研究了锌铝铜三元共晶合金中冷却速度对稀土锌合金的凝固组织和性能的影响。研究结果表明，稀土能细化锌合金的凝固组织和改善其机械性能，这些效果均受冷却条件的影响；冷却速度大，效果显著。但是，稀土锌合金的塑性比未加稀土的锌合金略低。在不同冷却条件下，锌合金中的稀土最佳加入量可能有所不同。     

RE对ZA-27合金组织和性能的影响

为进一步提高ZA-27合金的耐磨性,研究了RE对其组织和性能的影响。实验结果表明;RE使这种合金的晶粒细化,二次枝晶臂间距缩短,α相面积百分数略有增加。加入RE量大于0.1%时,基体中出现含RE硬质点,其形貌随RE加入量的提高而变化。RE的上述行为使ZA-27合金的强度和硬度略有提高,韧性降低,在润滑条件下的耐磨性可大辐度提高。     

RE 对 ZnAl4 合金组织和力学性能的影响

在ZnAl4合金中添加RE元素对其进行变质处理,通过金相组织和力学性能分析,研究了RE对该合金的显微组织和力学性能的影响。结果表明,基体中加入适量的稀土后,优化了组织结构,细化了晶粒,使合金的强度、硬度提10%以上,延伸率也有一定的提高。     

铝镁合金压铸用高性能稀土模具新材料 RE528的开发

本文从铝镁合金压铸用模具材料的性能要求入手,分析了常规模具材料的问题与不足,并以4Cr5W2VSi钢为基础,通过加入稀土元素和优化成分设计,成功研发一种具备优异冶金质量和组织性能、高附加值的稀土RE528热作模具新材料,其性能大大优于一般模具材料,具有良好应用前景。     

稀土处理对钢中夹杂和机械性能的影响

本试验是在氧气顶吹转炉200t 钢包中采用稀土1号混合粉剂,在16Mn 类、09Mn 类钢上进行的.通过对比试验明显看出:经处理后的钢中夹杂物种类发生显著变化,钢中夹杂含量也明显降低,提高了钢质的洁净度;提高了σ_、σ_b 值,尤其是横向上的和σ_b 值,改善了钢的δ_5、Ψ值;钢中夹杂物的类型、形状分布与稀土加入量、〔O〕/〔S〕比值和钢液二次氧化有关,并且与〔Xt〕〔S〕浓度积、〔Xt〕/〔S〕的比值有明显的对应关系,〔Xt〕〔S〕>1.7×10~(-4),〔Xt〕/〔S〕>1.7时,条状 MnS 消失。因此,在稀土处理工艺和浇铸过程中,必须采取相应的一系列保护措施.     

微量稀土对7075合金组织和性能的影响

对含微量稀土（质量分数0．061％以下）的三种7075合金，分别进行了物理性能，力学性能，抗腐蚀性能检测和显微结构研究结果表明：随着稀土含量增加，7075合金的旋转疲劳寿命延长，高温瞬时拉伸的延伸率有所提高，晶间腐蚀倾向略有减小，此外，对7075合金的其他组织和性能没有明显不良影响。     

不同稀土掺杂聚苯乙烯力学性能研究

选择了几种功能不同的Pr，Eu，Gd，Th，Dy，Ho和Er的三异丙氧基化合物与苯乙烯本体聚合获得稀土掺杂聚苯乙烯，采用ESEM，DMTA，冲击强度测试研究了不同稀土对聚合物力学性能的影响，结果表明不同稀土引入聚苯乙烯中均能使韧性得以提高，它们的力学性能与稀土的原子序数、原子半径大小有关。     

稀土对Al—Mg—Si系合金组织性能影响的分析

以实验为基础研究了稀土对Al-Mg-Si系铝合金的组织及性能的影响,并从理论上分析了稀土的作用机理。结果表明,稀土对合金组织具有改善作用,同时对春性能也有影响。最后对实验结果进行了分析与总结。     

稀土对真空熔结镍基自熔性合金涂层组织结构的影响

采用真空熔结的方法在45^#钢母材上获得了稀土。NiCrBSi自熔性合金涂层，借助X射线衍射、SEM及EDX研究了涂层截面的微观组织、相结构及涂层与母材界面附近的组织特征，讨论了稀土的加入对涂层组织结构的影响。结果表明：真空熔结NiCrBSi合金涂层为M基固溶体和分布在固溶体上块状、球状和针状的CrB，NiaB，Cr3C3和Cr23C6等第二相组成，涂层与母材为良好的冶金结合。添加稀土元素的NiCrB-SiRE合金涂层消除了针状组织，析出了新的硼化物NiB和硅化物Or65Ni25Si，第二相得到了进一步的球化；RE还阻碍了M，Cr，Si等原子向母材的扩散和Fe原子向涂层的扩散，减轻了Fe原子对涂层的“稀释”作用，保证了涂层的化学组成。     

Effect of Rare Earths on Corrosion Resisting Properties of Carbon-Manganese Clean Steels

Rareearthelementshavesignificantactionsinsteels ,includingwipingoffimpurityelements ,trans modifyinginclusions ,andimprovingmicrostructureetal,soaddingappropriaterareearthsintosteelscanef fectivelyimprovetheircorrosionresistingproper ties[1,2 ] .Todaypuri…     

Preparation and Performance of Rare Earths Chemical Conversion Film on Magnesium Alloy

Golden yellow cerium conversion film was obtained on magnesium alloys surface by immersion method and the preparation parameters were established. The influence of different process parameters on the surface morphology and performance of the conversion film were analyzed by means of SEM and electrochemical method. Formation dynamics about cerium conversion film on magnesium alloy in solution containing cerium salt and the anti-corrosion behavior of the conversion film in 3.5% NaCl solution were studied by electrochemical method respectively. The results shows that the conversion film is more compact at room temperature when concentration of cerium sulfate is 10 g·L-1 in the solution; the open circuit potential of the magnesium sample moves up to positive direction about 100 mV, the surface of conversion film becomes even and lustrous, and the adhesion intensity of conversion film increases when adding aluminum nitrate into the solution containing cerium salt. The pH value of the solution and immersion time of the sample in the solution also affect the surface morphology and anti-corrosion property of the conversion film. After covered by rare earths conversion film, the anti-corrosion property of magnesium alloy is obviously improved. Rare earth conversion film has self-repairing capability in corrosion medium.     

Effect of Rare Earths on Properties of BNbRE Rail Steel

The development and properties of BNbRE rail steel and the effect of RE on rail steel were studied. The results show that the properties of rail steel (δb ≥980 MPa, δ5≥ 8 % ) can be improved by adding RE and niobium and adjusting the content of C, Si and Mn in steel. At the same time, the abrasion resistance, contact fatigue and fatigue property of BNbRE rail steel are excellent. It also shows that RE in rail steel has the functions of purifying steel, modifying inclusion and micro-alloy action effect. The improved steel-making process enhances the quality of molten steel. Although the content of RE is low, excellent properties of BNbRE rail steel are achieved.     

Friction and Wear Characteristics of Mg-Al Alloy Containing Rare Earths

The influence of rare earth on the friction and wear characteristics of magnesium alloy AZ91 and AM60 were studied. The results show that the wear resistance properties of rare earth magnesium alloys are better than those of matrix alloy under the testing conditions. The anti-wear behaviour of AZ91 alloy is much better than that of AM60 alloy. In dry sliding pmcess, magnesium alloys undergo a transition from mild wear to severe wear. The addition of rare earths refine the structure of alloys, improve the comprehensive behaviors of magnesium alloys,increase the stability of oxidation films on worn surfaces,enhance the loading ability of rare earth magnesium alloys,and delay the transition from mild wear to sevre wear effectively.     

Effect of Cerium on Mechanical Properties and Morphology of ZZn4-1 Alloy

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稀土在钢铁焊接材料中的应用

本文参阅了近年来发表的大量文献，对稀土在焊接材料中的应用及其作用机理作了综述与评价。     

Effect of Rare Earths on Electronic Structure of (110) Twin Martensite Boundary for Ni2MnGa Alloy

The doping effect of rare earth elements (Tb and Sm) on the electronic structure of (110) martensitic twin boundary in Ni2MnGa alloys was investigated by using ab initio method within the DFT and the supercell implementation. The calculated results show that the atomic relaxation lowers the boundary energy and the segregation energy. Sm seems easier to segregate to the boundary and has a greater doping effect compared with Tb due to its lower segregation energy and bigger bonder order with neighboring atoms. Tb makes a greater contribution to the magnetic properties of the twin boundary than Sm.