铈盐和镧盐对铝合金阳极氧化膜性能的影响

通过对铝合金在含有稀土盐的硫酸电解液中进行阳极氧化所得到氧化膜性能的研究，发现加入硫酸铈比无稀土盐其厚度、硬度及耐蚀性均好，最佳含量为0．5g／L；硫酸铈和硫酸镧复合稀土盐比单一硫酸铈稀土盐好。     

镧-铈混合稀土变质剂对铸态高速钢组织与性能的影响

研究了镧-铈稀土变质对铸态高速钢组织及性能的影响。试验表明经稀土变质处理后,高速钢铸态组织中共晶碳化物明显细化,镧-铈混合稀土的添加促使共晶碳化物断网和团球化。此外,镧-铈混合稀土的添加提高了高速钢的冲击韧性和抗弯强度,其强度分别提高了26％和7．8％。     

稀土铈对热浸渗铝钢耐高温氧化性能的影响

研究了添加稀土铈对热浸渗铝钢渗层表面和耐高温氧化性能的影响，结果表明，在所研究的0％～1％范围内，随着稀土含量的增加，渗层的耐高温氧化性能逐渐提高。当稀土添加量为1．0％时，渗层的耐高温氧化性能最好，约为纯铝渗层的1．4倍，且添加稀土后，渗层表面形貌由片状向短棒状转变，韧性特征也比较明显。     

铈对锡磷青铜铸造与变形组织的影响

试验研究了铈对经过铸造、均匀化及再结晶退火的锡磷青铜QSn7-0.2合金的显微组织的影响特点,通过光学金相显微组织观察和电镜观察分析发现,加入少量稀土铈的锡磷青铜合金铸造组织枝晶网格变细小,变形退火后晶粒组织明显细化,添加少量稀土铈可净化合金中的有害杂质或消除其有害作用,并能与铜生成CuCeP金属间化合物,弥散分布在晶界或晶内,这些呈小黑点分布的第二相细化了合金组织,加铈又显著提高了合金强度和硬度,并确定了铈在锡磷青铜中的最佳添加量为0．10％－0．15％,这有效地改善了锡磷青铜合金的综合性能,延长了铜合金材料的使用寿命。     

稀土对钢焊缝组织的影响

通过在碱性药皮中添加稀土的正交试验，研究了不同稀土剂对钢焊缝组织的影响。结果表明，稀土能够抑制晶界铁素体和侧板条铁素体，促进针状铁素体并细化晶粒。按照作用效果，稀土剂的顺序为：稀土硅、稀土镁、氟化铈和氟铈镧矿。稀土剂的最佳添加量约为药皮干粉重量的3％．     

微量稀土元素铈对Sn-Ag-Cu无铅钎料物理性能和焊点抗拉强度的影响

研究了微量稀土元素铈对Sn-3．5Ag-0．5Cu无铅钎料的物理性能、润湿性能、焊点抗拉强度和显微组织的影响。结果表明，添加微量的铈后，钎料的导电性能提高，密度下降；铈含量（质量分数）在0．03％和0．05％时可以改善钎料的润湿性；特别是0．03％质量分数时晶粒组织最为细小均匀，焊点抗拉强度也最高；当铈含量（质量分数）大于0．1％时对钎料的性能产生不利影响，润湿时间升高，焊点抗拉强度大幅降低，因此稀土元素铈的最佳含量（质量分数）应为0．03％。     

用分光光度法测定稀土硬质合金中的铈

基于在稀硫酸介质中铈（Ⅳ）能氧化甲基红使之褪色的原理，建立了用分光光度法测定稀土硬质合金中的铈的操作步骤，并分析了Ｈ２ＳＯ４酸度、共存离子、甲基红用量等对测定的影响。结果表明：本法操作简便，试剂简单，可测定０．０１％～１％的铈。     

富铈稀土硅铁用作灰铁孕育剂的研究

本文研究了用富铈稀土硅铁(Ce10)作为孕育剂以考察其在高Si/C比铸铁中的孕育效果。Ce10的化学成分(％)为铈9.75,其它稀土12.2,硅44.04,钙1.1,铁余量。一、试验方法用三种碳当量的铸铁:低碳当量3.0～3.2％,中碳当量3.4～3.6％,高碳当量3.7～4.0％,以考查铈稀土Ce10的孕育效果     

低合金稀土高强度灰口铸铁的研制

介绍了ＣＥ３．９％，Ｓ（％）分别为０．００３、０．０５、０．１的三种灰口铸铁铁水加入稀土铈后白口深度、共晶团数及抗拉强度变化的情况。结果表明：含硫越高，白口深度越浅，共晶团增加越多，抗拉强度越大，且适宜的稀土加入量范围加宽。     

稀土对铸造铝合金中溶氢量及气孔形成的影响

研究了在常压和减压条件下，富铈混合稀土对钝铝，铸造铝铜合金和铸造铝硅合金中的溶氢量及气孔孔形成的影响。结果表明：稀土能使铝合金中的溶氢量减少，常压下的针孔率和减压下的孔隙明显降低，稀土的最佳加入量０．２％－０．３％。进一步讨论了稀土的作用机理。     

Prospects of the Use of Synergetic Approach to Solution of Problems of the Science of Nanomaterials

A synergetic approach to solution of problems of self-controlled synthesis of nanostructures and creation of self-organizing nanotechnologies is considered in connection with the superproblem of creation of materials with functional properties resembling those of biosystems. __________ Translated from Metallovedenie i Termicheskaya Obrabotka Metallov, No. 7, pp. 55 – 61, July, 2005.     

Kinetics of the oxidation of metals — Influence of self-diffusion of metal

The importance of the self-diffusion of a metal during its oxidation by a gas is treated for the cases of nonstoichiometric oxides having either interstitial cation or cation vacancies. We have established a general relationship for the reaction rate when a mixed diffusion process occurs. From this relationship, we have shown that the pressure dependence can be different, according to whether the rate-determining process is the self-diffusion through the metal or through the product.     

胫骨生物陶瓷复合材料的微结构增韧机理

扫描电镜观察显示胫骨是一种由羟基磷灰石和胶原蛋白组成的自然生物陶瓷复合材料.羟基磷灰石具有层状的微结构并且平行于骨的表面排列.观察也显示这些羟基磷灰石层又是由许多羟基磷灰石片所组成,这些羟基磷灰石片具有长而薄的形状,也以平行的方式整齐排列.基于在胫骨中观察到的羟基磷灰石片的微结构特征,通过微结构模型分析及实验,研究了羟基磷灰石片平行排列微结构的最大拔出能.结果表明,羟基磷灰石片长而薄的形状以及平行排列方式增加了其最大拔出能,进而提高了骨的断裂韧性.     

Mechanism of Nucleation of Precipitates of Carbides of Refractory Metals Under Hot Rolling of Automotive Sheet Steel

Metal Science and Heat Treatment - The problem of formation of properties in microalloyed sheet steels is considered. The cause and the possible mechanism of precipitation of carbides of refractory...     

燃煤机组锅炉烟气脱硝灰中氨含量测定

NOx是大气环境的主要污染物之一,其主要来源为火力发电机组。依靠低氮燃烧技术,远达不到排放要求。选择性催化还原脱硝(简称SCR)技术是目前效率最高、最成熟、应用最广泛的电厂烟气脱硝技术。目前,在线氨逃逸监测技术存在诸多问题,影响了氨逃逸监测数据的准确度和稳定性。在燃料种类、炉膛结构、受热面布置、过量空气量、炉膛气流分布以及脱硝催化剂类型等条件确定的情况下,控制好氨加入量及其逃逸量是保证NOx脱除率的关键所在。燃煤锅炉除尘飞灰氨含量可侧面反映脱硝氨逃逸率的状况。根据国外的文献报道,正常情况下,电除尘灰中氨含量一般在50mg/kg-100mg/kg范围内。由于国内尚无灰中氨含量的测定方法,亦无脱硝运行对飞灰含氨量影响的数据积累。本文通过大量试验,确定了灰中氨溶解条件(如溶解时间、搅拌状态、灰水比、灰样量及其稳定性等),制定了灰中氨含量测定方法。     

Features of formation of the structure in production of blanks of disks of heat-resistant nickel alloys

Conclusions To provide a high level of mechanical properties in wrought blanks of cast ÉP741NP and ÉP962 alloys it is necessary to form controlled structures. A necklace-type structure formed in homogenizing isostatic treatment, subsequent thermomechanical working including alternation of the operations of deformation in the (+)-area and recrystallization anneals, and final heat treatment is preferable. The temperature conditions of all stages of thermomechanical working are strictly controlled, especially the final operation of deformation and heating for hardening. To eliminate hardening cracks and distortions it is necessary to use molten salts at t=600°C as quenchants. The use of multiple production operations makes it possible to significantly reduce the structural inhomogeneity related to inhertance of the original dendritic structure. However, the structure of the final semifinished product is nevertheless characterized by a difference in occurrence of the processes of polygonization and recrystallization between the former dendritic cells and the interdendritic spaces in deformation and heat treatment.To obtain structurally homogeneous blanks for gas turbine engine parts it is necessary to use basically new methods of remelting such as vacuum double electrode remelting and electron beam remelting with an intermediate vessel.Translated from Metallovedenie i Termicheskaya Obrabotka Metallov, No. 12, pp. 25–29, December, 1991.     

Ab-initio calculation of enthalpies of formation of intermetallic compounds and enthalpies of mixing of solid solutions

A large number of ab-initio calculations of energies of formation of intermetallic compounds have been performed in the last 15 years. The currently used methods are listed. The paper presents a review of the aluminium based compounds which have been studied. Comparisons of calculated and experimental enthalpies of formation are provided for aluminim-3d and-4d transition metal alloys at equiatomic composition. The modelling of the enthalpies of mixing of solid solutions based on a given lattice is described.