7xxx系铝合金热处理的进展

7xxx系合金是基于Al-Zn-Mg（-Cu）系的可热处理的锻铝合金，广泛应用于高性能航空结构和运输部件。除了受成分、铸造和形变热处理影响外，材料性能的平衡明显受到其所经历的热处理方式的影响。描述了均匀化、固溶处理、淬火、时效对7xxx系高强合金组织和性能的影响。总结了在Monash大学进行的有关厚板产品的生产工艺，包括从均匀化到最终的时效处理，以及通过控制微观组织特征，比如弥散体、粗粒子、精细析出相、晶粒结构和晶界特征，来实现组织与性能的平衡。重点陈述了相关方法，如通过高温热处理溶解不需要的粗粒子、基于连续冷却析出行为的淬火敏感性变化、通过实验与建模来研究时效包括一步时效、两步时效、三步时效。对每种情况下的组织与性能都进行研究。     

904L(N08904)不锈钢复合板腐蚀性能研究

本文对904L+14Cr1MoR(H)和904L+Q345R两种复合板675℃消应力退火热处理后进行了系统的腐蚀试验,结果表明:复层904L发生晶粒粗大化,晶间存在碳化物析出,抗腐蚀性能受热处理影响显著。ASTM G150法临界点蚀温度CPT≥40℃,一般不超过904L原始状态的CPT;ASTM 262B法腐蚀速率11 mm/a;GB/T4334E法腐蚀,试样弯曲外侧面无晶间裂纹出现。     

Experimental evidence for enhanced copper release from domestic copper plumbing under hydrodynamic control

We present experimental results to analyze copper release from biotic and abiotic pipe surfaces and its relation to flow parameters, from Reynolds Number (Re) 1027–11,618.For abiotic and biotic surfaces, increasing the flow velocity affected the time scale of the copper release but not necessarily the net amount of total copper incorporated into the bulk flow.For biotic conditions the total copper concentration in the bulk flow was an order of magnitude higher than for abiotic surfaces (3.65 mg/L vs. 0.32 mg/L). Similarly, higher flow velocities enhance the presence of larger size copper nanoparticles in the bulk flow.     

A new solvent‐free super high build epoxy coating evaluated by marine corrosion simulation apparatus

Coal tar epoxy and epoxy asphalt coating have been widely used to protect marine constructions conventionally. However, their use is being restricted for increasing environmental concerns. Therefore, solvent‐free coating, i.e., coating without volatile organic compounds (VOCs) or hazardous air pollutant has become a new focus. Meanwhile, super high build (SHB) coating, having good anti‐corrosion performance and environment‐friendly feature, has become an important area of development in heavy‐duty protection to marine constructions. Herein, we combine the virtues of solvent‐free and SHB coating to introduce a new solvent‐free SHB heavy‐duty epoxy coating with no organic solvent and extremely low VOC content. Results show that the new coating is environment‐friendly, and has excellent physical properties and anti‐corrosion performance. The SHB coating performed much better than other three widely used coatings, especially in splash zone, the most dynamic area. The new solvent‐free SHB coating provides an ideal substitute to coal tar epoxy and epoxy asphalt coating and is expected to be widely used for anti‐corrosion of steel structures in splash, tidal, and immersed zones.     

彩色不锈钢的美学特性及应用

彩色不锈钢不仅呈现出色泽鲜艳、光亮的美学特性,还拥有诸多优良的物理性能,既适应了非线性建筑设计的潮流,也迎合了建筑材料可循环利用的发展趋势。通过对彩色不锈钢美学特性的分析,介绍其显色原理、着色工艺以及优良的性能,并对其应用前景进行展望。     

Conducting carbon/polymer composites as a catalyst support for proton exchange membrane fuel cells

Carbon/poly(3,4‐ethylene dioxythiophene) (C/PEDOT) composites are synthesized by in situ chemical oxidative polymerization of EDOT monomer on carbon black in order to decrease carbon corrosion that occurred in carbon‐supported catalysts used in proton exchange membrane fuel cell. The effects of different dopants including polystyrene sulfonic acid, p‐toluenesulfonic acid and camphorsulfonic acid with the addition of ethylene glycol or dimethyl sulfoxide on the properties of the composites are investigated. The synthesized composites are characterized by X‐ray diffraction, Fourier transform infrared spectroscopy, thermogravimetric analysis, surface area analysis and scanning electron microscope. Electrical conductivity is determined by using the four‐point probe technique. Electrochemical oxidation characteristics of the synthesized C/PEDOT composites are investigated by cyclic voltammetry by applying 1.2 V for 24 h. The composite prepared at 25 °C with p‐toluenesulfonic acid and ethylene glycol shows the best carbon corrosion resistance. Platinum‐supported catalyst by using this composite was prepared using microwave irradiation technique, and it was seen that the prepared catalyst did not significantly lose its hydrogen oxidation and oxygen reduction reaction activities after electrochemical oxidation. Copyright © 2013 John Wiley & Sons, Ltd.