Electrochemical investigation of the iron-containing and no iron-containing AB5-type negative electrodes

The electrochemical behaviour of LaNi_3.55Mn_0.4Al_0.3Co_0.75−xFe_x (x = 0, 0.15, 0.55, 0.75) intermetallic compounds has been studied and presented [C. Khaldi, H. Mathlouthi, J. Lamloumi, A. Percheron-Guégan, Int. J. Hydrogen Energy 29 (2004) 307–311; C. Khaldi, H. Mathlouthi, J. Lamloumi, A. Percheron-Guégan, J. Alloys Compd. 360 (2003) 266–271; C. Khaldi, H. Mathlouthi, J. Lamloumi, A. Percheron-Guégan, J. Alloys Compd. 384 (2004) 249–253]. It has been deduced that the LaNi_3.55Mn_0.4Al_0.3Co_0.4Fe_0.35 compound has interesting electrochemical properties. In this paper we present the electrochemical study of LaNi_3.55Mn_0.4Al_0.3Co_0.4Fe_0.35 compound properties compared with the parent LaNi_3.55Mn_0.4Al_0.3Co_0.75 compound. Several techniques, such as, the chronopotentiometry, the constant potential discharge (CPD), the cyclic voltammetry (CV) and the linear polarization (LP) were applied to characterize these electrochemical properties. The electrochemical discharge capacity of the LaNi_3.55Mn_0.4Al_0.3Co_0.75 alloy increases to reach 294 mAh g⁻¹ after few cycles only (five cycles). However, the activation of the LaNi_3.55Mn_0.4Al_0.3Co_0.4Fe_0.35 alloy takes more than 20 cycles to be achieved and the obtained maximum discharge capacity is 194 mAh g⁻¹. The hydrogen diffusion coefficient D_H was determined by constant potential discharge and cyclic voltammetry techniques. The obtained values of the LaNi_3.55Mn_0.4Al_0.3Co_0.75 and LaNi_3.55Mn_0.4Al_0.3Co_0.4Fe_0.35 compounds are 6.29 × 10⁻¹¹ and 7.62 × 10⁻¹¹, and 2 × 10⁻⁸ and 7.5 × 10⁻⁸ cm² s⁻¹ by CPD and CV techniques, respectively. The exchange current density values, determined by a linear polarization technique, are 44 and 27 mA g⁻¹, respectively, for LaNi_3.55Mn_0.4Al_0.3Co_0.75 and LaNi_3.55Mn_0.4Al_0.3Co_0.4Fe_0.35 alloys.     

燃烧合成焊接钢/不锈钢焊缝结构及形成机制

摘要将燃烧合成技术与传统焊接技术相结合，以Ti-Ni体系为连接材料研究了08钢/1Cr18Ni9不锈钢焊接焊缝的形成过程，探索了Ti-Ni加压燃烧合成的过程及产物的形成机制，焊缝与基体的结合行为。目的在于开发出一种新型层状金属复合材料的制备工艺。     

板料成形模拟后处理中的截面物理量的显示技术*

在自行开发的板料成形有限元后置处理系统FASTAMP_POST中,采用了动态获取截面物理量的算法,实现了截面物理量实时显示功能。该功能真实反映了网格物理量的大小及其变化趋势,具有原理简单、易实现、执行速度快的优点。     

Functionalized metal–organic frameworks with strong acidity and hydrophobicity as an efficient catalyst for the production of 5-hydroxymethylfurfural

In the dehydration of fructose to 5-hydroxymethyl furfural(HMF), in situ produced water weakens the acid strength of the catalyst and causes the rehydration of HMF, causing unsatisfactory catalytic activity and selectivity. In this work, a class of benzenesulfonic acid-grafted metal–organic frameworks with strong acidity and hydrophobicity is obtained by the direct sulfonation method using 4-chlorobenzenesulfonic acid as sulfonating agent. The resultant MOFs have a specific surface area of greater than 250 m~2·g~(-1), acid density above 1.0 mmol·g~(-1), and water contact angle up to 129°. The hydrophobic MOF-Ph SO_3 H exhibits both higher catalytic activity and selectivity than MOF-SO_3 H in the HMF synthesis due to its better hydrophobicity and olephilicity. Moreover, the catalyst has a high recycled stability. At last, fructose is completely converted, and 98.0% yield of HMF is obtained under 120 °C in a DMSO solvent system. The successful preparation of the hydrophobic acidic MOF provides a novel hydrophobic catalyst for the synthesis of HMF.     

Electronic Theory of Thermodynamic Adhesion inMetal/Ceramic Systems

ＥｌｅｃｔｒｏｎｉｃＴｈｅｏｒｙｏｆＴｈｅｒｍｏｄｙｎａｍｉｃＡｄｈｅｓｉｏｎｉｎＭｅｔａｌ／ＣｅｒａｍｉｃＳｙｓｔｅｍｓＬｉＪｉａｎ＇ｇｕｏ（李建国）（ＩｎｓｔｉｔｕｔｆｕｒＮｉｃｈｔｍｅｔａｌｌｉｓｃｈｅＷｅｒｋｓｔｏｆｆｅ，ＴｃｈｎｉｓｃｈｅＵ...     

高炉风口表面处理技术

介绍近代高炉风口采取等离子喷涂、各种金属渗镀和堆焊高温耐磨合金3种方法进行表面处理的情况。我国中小高炉多趋向发展多元金属渗镀,前苏联和日本风口经堆焊后抗磨性能有明显改善,采用上述3种处理后风口寿命均有数倍的提高。     

CIM技术在塑性成型工程的应用

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金属磁记忆检测技术概况及初步应用

介绍金属磁记忆检测技术的背景、发展、现状、目的和意义，用两个应用实例初步评价了磁记忆检测技术的有效性，提出了磁记忆技术发展的近期和远期目标，展望了应用前景。     

Thixoforging of continuous fiber-reinforced AlSi/AlMg-alloys

High strength in combination with low density is the key features for lightweight constructions in automotive and aerospace applications. Tailor-made fiber reinforcements in light-metal matrices could help to achieve this goal. However, the integration of fibers with conventional casting-route manufacturing techniques like squeeze casting or diffusion bonding restricts the component geometry and results in elevated process cost due to long cycle times and the need of additional fiber coatings. In the center of competence for casting and thixoforging Stuttgart (CCT), new processes for manufacturing metal matrix composites are developed. Long-fiber reinforced Al–Si alloys and components are produced by thixoforging of laminates made of alternating metal matrix layers and carbon fiber fabrics. This paper illustrates the manufacturing technology and first experimental results with special focus on fiber penetration and infiltration behavior and also on the formation of fiber-matrix interface to analyze fiber damage by mechanical or chemical attack.     

金属注射成形技术进展

分析了影响金属注射成形（ＭＩＭ）产业化进程的两个主要技术因素，即适合ＭＩＭ要求的原料粉末的生产方法和ＭＩＭ生产工艺，并概述了目前ＭＩＭ技术的发展状况。