电镀及化学镀磁记录介质薄膜的最新进展

本文综述了近年来国外电镀及化学镀磁记录介质薄膜的最新研究进展、电镀及化学镀镀液组成、工艺条件及其对薄膜性能的影响、存在问题及发展方向等．磁记录介质薄膜的制备，过去一直采用溅射方法，近年来国外开展了电镀及化学镀方法制备的研究．电镀方法包括水溶液电镀（如：Ｎｉ－Ｆｅ、Ｆｅ－Ｃｏ合金等）和非水溶液电镀（如Ｔｂ－Ｆｅ、Ｎｄ－Ｆｅ、Ｔｂ－Ｆｅ－Ｃｏ合金等），化学镀则是在Ｎｉ－Ｐ、Ｃｏ－Ｐ合金的基础上，通过添加其它金属盐，得到磁记录介质薄膜，如：Ｃｏ－Ｎｉ－Ｐ、Ｃｏ－Ｗ－Ｐ、Ｃｏ－Ｍｎ－Ｐ、Ｃｏ－Ｎｉ－Ｒｅ－Ｐ合金等     

p—Si上电沉积Ni—W—P薄膜的结构与热稳定性

研究了ｐ－Ｓｉ上恒电流沉积Ｎｉ－Ｗ－Ｐ合金薄膜组成与结构的关系，讨论了镀层的组成、结构随沉积时间的变化．测定了非晶合金的晶体结构随热处理温度的改变以及ＤＴＡ曲线，结果表明，非晶Ｎｉ－Ｗ－Ｐ合金在晶化过程中形成两个纳米超微晶相，非晶Ｎｉ－Ｗ－Ｐ薄膜的热稳定性远高于通常使用的非晶Ｎｉ－Ｐ薄膜．     

Fe—15Cr—4Al—Y合金中的Y—Fe相及其作用

在含０．２％－１．４％Ｙ的Ｆｅ－１５Ｃｒ－４Ａｌ－Ｙ合金中，１－１０μｍ的Ｙ－Ｆｅ相质点弥散分布，其硬度高于ａ相的２倍，组成可用Ｙ２（Ｆｅ７６Ｃｒ１２Ａｌ１１Ｓｉ）１７表示。Ｙ－Ｆｅ相强烈俘获ａ相中的碳原子，使合金在固溶处理状态下的Ｓｎｏｅｋ内耗峰消失，在７００℃下析出碳化物。Ｙ－Ｆｅ相南点通过阻止闰长大而抑制合金的高温脆化，通过俘获碳原子而延缓４７５℃脆性发展。此外，它们还有提高热强性和抗氧化性     

急冷Al—Fe—V—Si—Mu合金的穆斯堡尔谱研究

利用穆斯堡尔谱和Ｘ射线和衍射研究了４种Ａｌ－Ｆｅ－Ｖ－Ｓｉ－Ｍｕ合金的Ｆｅ的原子组态。结果表明，添加混合稀土元素后抑制了基体合金Ａｌ－Ｆｅ－Ｖ－Ｓｉ中α－Ａｌ１３（Ｆｅ，Ｖ）３Ｓｉ弥散粒子相的析出；当稀土含量６ａｔ％时，形成了Ａｌ－Ｆｅ－Ｖ－Ｓｉ－Ｍｕ非晶态，采用Ｖｏｉｇｔ基函数作了穆斯堡尔谱的合理拟合和分析。     

电镀Fe－Cr－Ni合金显微结构研究

电镀Ｆｅ－Ｃｒ－Ｎｉ合金显微结构研究①李东林＊刘建平郭芳洲华建荣（南方冶金学院化工系,江西赣州３４１０００）Ｆｅ－Ｃｒ－Ｎｉ合金,一直是电镀工作者研究的对象［１,２］．Ａ．Ｍ．Ａｎｄｅｒｓｏｎ［３］等人从多种Ｃｒ（Ⅲ）的水溶液中镀出了Ｆｅ－Ｃｒ－Ｎｉ...     

三元合金生成热的一种计算方法

本文将半经验模型计算二元合金生成熟的方法，推广至三元合金，计算了Ｌａ－Ｆｅ－Ａｌ，Ｆｅ－Ａｌ，Ｆｅ－Ｎｉ－Ｖ，Ｃｕ－Ｐｄ－Ｓｉ等三元合金体系生成热，并与实验结果比较，符合很好，这种计算方法可预测三元合金生成热及固溶区的范围，并可最终产物存在的可能性。     

铁钴镍铜锌镉铝在聚乙二醇—硫酸铵—茜素S体系中萃取分离

本文用茜素Ｓ作萃取剂，研究了Ｆｅ，Ｃｏ，Ｎｉ，Ｃｕ，Ｚｎ，Ｃｄ，Ａｌ在聚乙二醇－硫酸铵－茜素Ｓ体系中的非有机溶剂萃取行为。实验结果表明，在ｐＨ５的ＨＡｃ－ＮａＡｃ缓冲溶液中，Ｆｅ，Ａｌ与茜素Ｓ的络合物可被ＰＥＧ相几乎完全萃取，Ｃｕ，Ｎｉ部分被萃取，而Ｃｏ，Ｚｎ，Ｃｄ则不被萃取，从而实现了Ｆｅ与Ｃｏ，Ｚｎ，Ｃｄ及Ａｌ与Ｃｏ，Ｚｎ，Ｃｄ混合离子间的定量分离。     

分子筛和γ—Al2O3混合载体上负载Ni和W的加氢裂解催化 …

运用ＥＸＡＦＳ技术对Ｎｉ和Ｗ负载于４种改性Ｙ分子筛与Ａｌ２Ｏ３混合载体上的加氢裂解催化剂进行了研究,结果表明,硫化态催化剂中Ｗ和Ｎｉ均未被完全硫化,除硫化态外,大部分Ｗ处于钨氧硫（ＷＯＳ）状态,而部分Ｎｉ为氧化物,不同分子筛对Ｎｉ和Ｗ的硫化程度的影响不同。另外催化剂中存在少量的ＮｉＷＳ相,载体的Ｂ酸位与催化剂中的ＮｉＷＳ相的多少有较好的相关性。     

电感耦合等离子体原子发射光谱测定镁—钕合金中稀土和非稀土元素

本文研究了ＩＣＰ－ＡＥＳ测定Ｍｇ－Ｎｄ合金样品中１０种元素的分析方法。选择了同时测定合金中Ｌａ、Ｃｅ、Ｐｒ、Ｓｍ、Ｆｅ、Ａｌ、Ｍｏ、Ｎｉ、Ｃｕ和高含量Ｎｄ（２０％）的条件。得到了满意结果。     

氧化铈在非贵金属氧化物催化剂中的作用：Ⅵ.Cu—Fe—Ce—O催化剂的结 …

采用ＸＲＤ,顺磁共振（ＥＳＲ）,Ｍｏｓｓｂａｕｅｒ和或温还原（ＴＰＲ）技术对负截型Ｃｕ－Ｆｅ－Ｏ（Ⅰ）,Ｃｕ－Ｆｅ－Ｃｏ－Ｏ（Ⅱ）催化剂的固相结构及热稳定性进行了研究。结果发现,（Ⅰ）中主要存在Ｆｅ２ＣｕＯ４,ＣｕＯ和颗粒度小于１３ｎｍ的Ｆｅ２Ｏ３相。随着焙烧温度的升高,ＣｕＯ晶相逐渐消失,Ｆｅ２ＣｕＯ４的晶相长大。（Ⅱ）中Ｃｅ的存在,能提高Ｃｕ＾２＋的浓度,抑制ＣｕＯ和Ｆｅ２ＣｕＯ４晶相的生成,     

Embrittlement of tungsten heavy alloys by trace impurities and their analytical characterization

Summary The effects of various trace elements on properties and fracture modes of heavy alloys are described. It has been found that tungsten heavy alloys can be embrittled by traces of Al, Si and P, while various other impurities are ineffective. In all cases embrittlement is caused by deterioration of the interfacial strength between binder and W grains. Al is not embrittling itself but preserves the oxygen, which is the embrittling element. Fractography by SEM is recommendable for correctly assessing the significance of the AES results.

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Versprödung von Wolfram-Schwermetallen durch Spurenverunreinigungen und ihre analytische Charakterisierung

     

Quantitative Mass Spectrometry of Decarburisation and Denitridation of Cemented Carbonitrides During Sintering

 Quantitative quadrupole mass spectrometry of (Ti, W)C-based cemented carbonitrides was carried out in order to monitor the evolution of the gas species as a function of time and temperature during vacuum sintering. Solid standards and gas mixtures as well as precise flow control were employed for calibration. Upon integration of the outgassing rates the carbon and nitrogen evolutions and mass losses during sintering of raw hardmetal powder mixtures (WC, TiC,…) and cemented carbonitrides could be quantified. Outgassing occurs in the range of temperatures 490–1480 °C. Nitrogen outgassing of (Ti, W)(C, N) was greater than that of Ti(C, N) due to the presence of W which increases the nitrogen activity in the solid causing a higher nitrogen equilibrium pressure. TiN showed a CO (0.2 wt%) and N₂ (0.5 wt%) weight loss only in the presence of the binder phase. For powder mixtures, it was observed that the amount of CO, CO₂ and N₂ liberated during vacuum sintering increased with the addition of cobalt in comparison with the same powders without binder phase. Nitrogen containing cermet alloys showed a greater loss of carbon than (Ti, W)C-based hardmetals. A careful control of carbon content by doping seems to be necessary in such alloys to avoid η-phase formation. Received July 7, 2000. Revision December 4, 2000.     

Electrodeposition, Structure and Corrosion Resistance of Nanocrystalline Ni-W Alloy

Ni—W alloy was electrodeposited from the electrolyte solution containing sodium tungstate, nickel sulfate and ammonium citrate. The electrodeposition, heat treatment, structure, surface morphology and corrosion resistance in w=0.03 NaCl solution, of Ni-W alloys were studied by means of DSC, XRD, SEM and electrochemical techniques. The results showed that the obtained Ni-W alloy electrodeposit with W weight content (Ww=0.471) was presented in more typical nanocrystaUine, After heat treatment at 400 ℃ for 1 h, the phase structure of the deposits was not obviously changed whereas the agglomerate for the reunion of tiny grains on deposit surface caused the granule in a more smooth morphology, the microhardness was slightly increased and the corrosion resistance was enhanced.     

Chemical analysis of the submicron binder phase in hard metals

Summary Chemical Analysis of the Submicron Binder Phase in Hard Metals The chemical analysis of the cobalt binder phase in sintered hard metals poses severe problems if performed by means of physical methods of surface analysis, such as SIMS, EMPA or AES. Compared with their limit of lateral resolution the average mean free path of the binder phase between the carbide particles, especially in micrograin hard metals, is less than 500 nm and thus too small. An electrochemical technique has been developed by which the carbide phase can be selectively etched away from the surface of a polished section, leaving the cobalt binder phase chemically and morphologically unchanged. The carbide-free cobalt binder phase can now be separated from the bulk hard metal using a technique similar to the well-known extraction replica technique commonly applied in transmission electron microscopy. The extracted binder phase can then be analyzed by X-ray fluorescence or other methods.     

Glutaraldehyde crosslinking of arabinoxylan produced from corn ethanol residuals

This study investigated the possibility of substituting petroleum-based polymers with biopolymers for films and paper coatings. Arabinoxylan (AX) was extracted from distillers’ grains, a low-value corn ethanol byproduct, and modified through crosslinking with glutaraldehyde (GA) which was made into films and paper coatings. The effects of degree of substitution (DS) on film and coating properties of GA cross-linked AX, referred to as GAX, were investigated. The GAX films had markedly higher tensile strength, approximately 3 times higher than the unmodified AX films at low DS, with higher DS causing a negative effect on the film tensile strength. Compared to unmodified AX coating, paper coated with GAX also had significantly higher tensile index, presumably due to high adhesion between the coating and paper interface. When used as a coating binder with calcium carbonate pigments, GAX showed comparable performance to polyvinyl alcohol, a common industrial binder, demonstrating the potential to be substituted for the petroleum-based paper coating binder.     

基于光强传输方程的多模式成像

在显微成像中,对于相位的恢复和定量相位的成像,基于光强传输方程的定量相位成像是一种有效的方法。在沿光轴分布的光强中采集一系列强度图像,利用数值差分估计光强在聚焦面处的一阶轴向微分并通过求解光强传输方程直接得到相位信息。该方法不需要复杂的干涉装置和参考光束,且能够在传统的明场显微镜下实现定量相位成像。近年来,光强传输方程在国内外得到广泛研究和关注,在自适应光学、X射线衍射光学、电子显微学、光学显微成像等领域中显现出巨大的应用前景。本文提出了一种基于光强传输方程的多模式成像系统,将传统的显微镜和计算成像结合起来,赋予了传统显微镜获得定量相位的能力。采用该系统对未染色的花粉粒以及海拉细胞的有丝分裂过程进行了显微观察,验证了系统的多样性与可靠性。     

多孔β－TCP生物降解陶瓷的拉曼光谱

求文研究了多孔Ｂ－ＴＣＰ生物降解陶瓷及其粘结剂的拉王光谱。参照各种磷酸盐及磷酸盐玻璃的拉曼光谱，对生物降解陶瓷的拉曼特征频率进行了经验式的归属和指认。实验结果表明，生物降解陶瓷以β－Ｃａ３（ＰＯ４）２（β－ＴＣＰ）为主晶相，当粘结剂含量增加时，生物降解陶瓷中出现明显的Ｃａ４Ｐ２Ｏ９９和Ｃａ２Ｐ２Ｏ７，晶相和其他非晶相，其含量随粘结剂量增加而增加，并呈现一种多孔的网络结构。     

p－Si上电沉积Ni－W合金薄膜

利用恒电流沉积法，在ｐ－Ｓｉ上制备出不同Ｗ含量和不同结构的Ｎｉ－Ｗ薄膜，研究了镀液温度，ｐＨ值，电流密度对镀层组成的影响，结果表明，提高温度有利于获得高Ｗ含量的合金．随着镀层中Ｗ含量的增加，Ｎｉ面心立方晶格ｆ．ｃ．ｃ发生正畸变，晶粒平均尺寸变小，当Ｗ含量达到５６％以上时，晶粒小于２ｎｍ，薄膜呈非晶态结构．     

硫化态NiW/Al2O3催化剂加氢脱硫活性相的研究Ⅱ.程序升温还原表征

 采用程序升温还原法对一系列具有相同W含量和不同Ni含量的硫化态NiW/Al2O3催化剂进行了表征,以考察催化剂中不同硫物种的数量及还原性能. 结果表明,含有助剂Ni的催化剂TPR谱在673~873 K出现了一个还原峰,归属为催化剂的NiWS混合相被分解生成的硫化镍物的还原. 随着助剂Ni含量的增加,与该还原峰相应的H2S生成量增大,表明形成了更多的NiWS活性相. 另外,Ni/(Ni+W)原子比为0.41的催化剂样品的噻吩加氢脱硫活性随着还原温度的升高而急剧下降,证实了催化剂在还原过程中活性相被逐步分解.