7N01-T4铝合金腐蚀疲劳行为研究

开展了7N01-T4铝合金在实验室空气、潮湿空气和3.5%Na Cl盐雾环境下的疲劳S-N曲线测试,研究了这2种腐蚀介质对7N01-T4铝合金疲劳性能的影响。结果表明:7N01铝合金在2种腐蚀介质下缺口敏感度系数比实验室空气环境下的缺口敏感度系数出现不同程度的下降,其中潮湿空气环境下缺口敏感度系数的影响大于3.5%Na Cl盐雾环境;2种试样形式(Kt=1和Kt=3)无论是在潮湿空气环境下还是盐雾环境下的腐蚀影响系数相当接近,3.5%Na Cl盐雾环境腐蚀影响系数小于潮湿空气环境;潮湿空气环境和3.5%Na Cl盐雾环境DFR值均有不同程度下降,3.5%Na Cl盐雾环境对DFR值的影响大于潮湿空气。     

喷雾降温技术在阳极炉高温烟气降温中的应用

介绍了喷雾降温技术的特点,以及喷雾降温系统工艺及技术参数的设置、控制逻辑和应用效果。该技术在国内铜冶炼烟气冷却中应用较少,而国外几家铜厂已开始取代余热锅炉,成功应用在转炉烟气的冷却上。因其温度控制精度高、投资省、设备简单和占地空间小等优点,将在高温烟气的冷却上广泛应用。喷雾降温技术应用于云南铜业冶炼加工总厂阳极炉高温烟气的冷却,整个喷雾降温系统运行正常,实现了初期的降温目标要求,有效地解决了固定阳极炉高温烟气的冷却问题,使烟气得到了有效除尘净化。     

1700mm冷连轧机轧辊分段冷却对热辊型的影响研究与应用

以某厂1 700五机架冷连轧机的工作辊为研究对象,综合分析了喷水冷却对轧辊热辊型的影响,找到了水温、水压、水流、喷射距离和喷射角度等参数在控制轧辊热凸度方面的调控范围。对轧辊轴对称温度场模型进行简化,采用MatLab编制仿真软件,并将仿真计算结果与现场实测数据进行了对比,说明喷水冷却对热辊型影响分析及仿真软件的准确性,对冷连轧机板型的控制起到指导作用。     

纳米石墨包覆球形LiFePO_4正极材料的制备及其性能研究

采用湿球研磨-喷雾干燥法合成了纳米石墨包覆的球形LiFePO_4材料。该材料呈现了大小较为均匀的球形颗粒,颗粒度较小。性能测试表明该材料具有优异的电化学性能,最佳样品C在0.1 C时的放电比容量为160.9 m A·h·g~(-1),在高倍率5 C下的比容量仍为120.5 m A·h·g~(-1),显示了良好的比容量维持率。该法制备细小而致密的球形颗粒,并通过纳米石墨包覆增强导电性,大大提高了LiFePO_4材料的电化学性能,此方法简便、高效,有工业化应用的前景。     

喷射成型高强度铝合金在固体火箭发动机上的应用

将喷射成型高性能铝合金,用于固体火箭发动机的结构材料.计算与试验结果表明,喷射成型铝合金的室温比强度高于传统铝合金、钢,在试验所选定的部件上替代传统材料,用于固体火箭发动机的构件,通过了各种性能检测,减重55%~69%,表明喷射成型高性能铝合金在固体火箭发动机上应用前景广阔.     

Effects of spray drying conditions on the physicochemical and antioxidant properties of the Gac (Momordica cochinchinensis) fruit aril powder

Gac fruit aril has an attractive orange red colour and very high level of carotenoids, giving it exceptional antioxidant properties. However, spray drying of this material has not been successful and malto dextrin is considered as a suitable drying aid to preserve its colour and antioxidant properties. This paper reports the effects of inlet drying air temperature (120, 140, 160, 180 and 200 °C) and maltodextrin addition (10%, 20% and 30%) on the physicochemical and antioxidant properties of the Gac aril powder. Moisture content and bulk density, colour characteristics, total carotenoid content (TCC), encapsulation efficiency and total antioxidant activity (TAA) were significantly affected by maltodextrin concentration and the inlet air temperatures. However, pH, a_w and water solubility index were not significantly influenced by the spray drying conditions. Overall, a good quality Gac powder in terms of colour, TCC and TAA can be produced by spray-drying at inlet temperature of 120 °C and adding maltodextrin concentration at 10% w/v.     

Effect of drying methods on the physical properties and microstructures of mango (Philippine ‘Carabao’ var.) powder

Mango powders were obtained at water content below 0.05 kg water/kg dry solids using Refractance Window® (RW) drying, freeze drying (FD), drum drying (DD), and spray drying (SD). The spray-dried powder was produced with the aid of maltodextrin (DE = 10). The chosen drying methods provided wide variations in residence time, from seconds (in SD) to over 30 h (in FD), and in product temperatures, from 20 °C (in FD) to 105 °C (in DD). The colors of RW-dried mango powder and reconstituted mango puree were comparable to the freeze-dried products, but were significantly different from drum-dried (darker), and spray-dried (lighter) counterparts. The bulk densities of drum and RW-dried mango powders were higher than freeze-dried and spray-dried powders. There were no significant differences (P ? 0.05) between RW and freeze-dried powders in terms of solubility and hygroscopicity. The glass transition temperature of RW-, freeze-, drum- and spray-dried mango powders were not significantly different (P ? 0.05). The dried powders exhibited amorphous structures as evidenced by the X-ray diffractograms. The microstructure of RW-dried mango powder was smooth and flaky with uniform thickness. Particles of freeze-dried mango powder were more porous compared to the other three products. Drum-dried material exhibited irregular morphology with sharp edges, while spray-dried mango powder had a spherical shape. The study concludes that RW drying can produce mango powder with quality comparable to that obtained via freeze drying, and better than the drum and spray-dried mango powders.     

聚氯乙烯糊用树脂喷雾干燥技术的进展

概括了目前PPVC喷雾干燥的生产情况,最新的生产流程,对于关键设备的改进提出了方法。     

熔融金属喷射沉积技术的发展与应用

喷射沉积是１种快速凝固材料制备新技术。本文叙述该技术的产生及应用发展和原理。在贵金属材料领域将有重要的应用 。     

SYNTHESIS OF NANOSTRUCTURED LiM0.15Mn1.85O4 (M = Mn,Co, Al,AND Fe) PARTICLES BY SPRAY PYROLYSIS IN A FLUIDIZED BED REACTOR

A novel technique has been developed to directly produce fine ceramic powders from liquid solution via spray pyrolysis in a fluidized bed reactor (SPFBR). Using this technique the preparation of LiM_0.15Mn_1.85O₄ (M = Mn, Co, Al, and Fe), which are the most promising cathode materials for lithium-ion batteries, has been carried out at a superficial velocity U₀ of 0.71 m/s, a reactor temperature T of 800°C, and a static bed height L_s of 100 mm. The as-prepared powders were spherical nanostructured particles that comprised primary particles of a few tens of nanometers in size, and they exhibited a pure cubic spinel structure without any impurities in the XRD patterns. The chemical composition of as-prepared samples showed good agreement with the theoretical values that proved stoichiometric formulae of the compounds. The specific surface area of as-prepared LiM_0.15Mn_1.85O₄ (M = Mn, Co, Al, and Fe) powders decreases with increasing the static bed height in each doping metal, while the crystallite size increases with the static bed height. As a result, the as-prepared powders showed larger crystallite size and smaller specific surface area than those prepared by conventional spray pyrolysis.