TA32钛合金板成形性能与电磁辅助弯曲成形实验研究

由于TA32钛合金板室温成形性差、精度难以保证,开展了电磁辅助弯曲成形方法的实验研究,通过拉伸和电磁成形实验探究了TA32钛合金的力学性能和成形性能,获得了TA32钛合金板在准静态和动态拉伸下的应力、应变关系,给出了在电磁成形状态下的成形极限应变,阐明了电磁成形作用下的TA32钛合金的增塑机制。采用匀压式电磁辅助弯曲成形的方法对TA32钛合金板开展实验研究,结果表明:电磁辅助弯曲成形方法能够有效地提高弯曲件的成形精度,并且在一定条件下,放电能量越高,贴模效果越好、成形精度越高。带压紧翼的弯曲件的变形区外层过度伸长而产生减薄并开裂,不带压紧翼的弯曲件通过合理地控制放电电压能够获得较好的成形效果。     

热轧钢卷强制冷却工艺的研究

试验研究了热轧钢卷的强制冷却工艺过程 ,探讨了钢卷强制冷却工艺参数对带钢表面质量、力学性能及板形等的影响 ,认为卷取后采用间断式强冷工艺可获得较好的表面质量、较均匀的力学性能 ,并能明显缩短钢卷库存时间     

汽车稳定杆组织与疲劳性能研究

对28Mn6钢制造的汽车稳定杆，分别采用整体感应加热-整体淬火、连续感应加热淬火两种不同工艺热处理，并进行了台架疲劳寿命试验。采用光镜分析了不同稳定杆的金相组织，用扫描电镜分析了早期疲劳断裂的稳定杆断口形貌。结果表明，获得细小的高韧性索氏体组织是保证良好疲劳寿命的关键，稳定杆喷丸表面质量、游离铁素体也是影响疲劳性能的重要因素。     

先进开卷落料线的工艺规划设计

开卷落料线是一种适用于汽车、钢板配送等行业高档外饰卷板的板材加工设备。本文通过对开卷落料线各模块功能分析,论述了开卷落料线建线中的开卷输送系统设计、主要加工设备选用、堆垛装置设计等。开卷落料线的工艺规划设计应该充分考虑铝合金板材的应用。分析结果表明,钢铝混合开卷落料线的工艺规划设计可以满足未来生产线的发展需要,同时可以大大降低企业设备投资及生产区域面积。     

基于音圈电机X-Y精密定位平台的控制系统设计

针对由音圈电机驱动的X-Y精密定位平台系统,提出了一种基于S函数的实时离散傅里叶变换(DFT)算法来进行系统辨识,从而建立定位平台的数学模型.基于系统数学模型,采用混合灵敏度优化的方法,设计了一种H∞鲁棒控制器.该控制器对模型的不确定性及外部干扰具有较好的抑制作用,从而能够很好地改善系统性能,并利用仿真及实时控制实验验证该控制算法的有效性.结果表明该控制器较好的改善了系统的动态特性,使其具有响应速度快、稳定性好以及良好的抗干扰能力等优点.     

10万t/a合成氨一段炉低温烟道气节能改造小结

四川美丰10万t/a合成氨一段炉低温烟道气余热回收改造,在不改动对流段箱体和引风机前提下,巧妙利用有限空间设计增加换热盘管和增加原水质换热盘管换热面积,进一步回收了烟道气余热,并回收处理了较大部分低变气冷凝液,减少了污染物排放,做到了节能与减排有机结合。     

预涂金属卷材用水性环氧聚酯底漆的研制

将水性环氧树脂、丙烯酸改性饱和聚酯树脂、氨基树脂、插层改性累托石、各种颜填料和助剂按比例制成预涂金属卷材用水性环氧聚酯底漆。讨论了不同颜基比以及不同用量的环氧树脂、颜填料、插层改性累托石和偶联剂对漆膜性能的影响。获得了水性环氧聚酯底漆最佳配方:环氧树脂用量占树脂总固体分的15%,锶铬黄和插层改性累托石的用量分别占颜填料用量的30%和2%~3%,硅烷偶联剂1%。所得漆膜的附着力0级,硬度2H,T弯0,耐MEK擦试70次,抗流挂性和流平性良好。     

Morphology and photophysical properties of a thermally responsive fluorescent material based on a rod‐coil tri‐block copolymer

A thermally responsive rod‐coil poly[poly (N‐isopropylacrylamide)‐b‐polyfluorene‐b‐poly(N‐isopropylacrylamide)] triblock copolymer has been successfully synthesized by atom transfer radical polymerization from an end‐functionalized macroinitiator. The thermochromic behavior and relevant morphology of this polymer were investigated by UV‐vis spectra, DLS, and AFM, respectively, at various temperatures. A thermally responsive fluorescent material was achieved facilely by combining the optically active polyfluorene with temperature‐responsive poly(N‐isopropylacrylamide). All the measurements demonstrated that in the region of 25–45°C, the polymer underwent a phase transition and the corresponding change in optical properties in its water solution. However, the polymer did not show completely reversible behavior upon heating and cooling. On the basis of the comparison with two other thermally responsive conjugated polymers in literatures, a tentative mechanism has been proposed that π–π interaction induced rigid segments to remain chain conformation and packing styles as in collapsed state. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

一种热轧带钢平整分卷线张力控制工艺

针对传统的热轧带钢平整线一阶张力控制工艺存在带钢表面划伤和卷形错层的问题,开发了一种新型二阶张力控制工艺,其通过配置开卷机、矫直机、平整机、张力装置和卷取机等设备作为张力分段点,实施二阶递增张力控制策略,提高了带钢表面质量,以及板形和卷形质量。     

SAR of a birdcage coil with variable number of rungs at 300 MHz

The specific absorption rate produced in a rat’s brain phantom inside of quadrature birdcage coil as a function of the rung number was studied at 300 MHz. Electromagnetic field simulations and specific absorption rate and loss return responses were performed using a rat’s brain phantom weighing 100 mg. To assure optimal simulations and to evaluate coil performance, S-parameters were simulated and compared with experimentally data. Simulations showed that magnetic field uniformity improves and that electric field is increased with the number of rungs. Specific absorption rate and temperature values obtained from axial bi-dimensional maps increase as the number of rungs grows. These results corroborated very well with published data. A quadrature 16-rung birdcage coil was developed for comparison and phantom images were acquired to show its feasibility. The presented approach yields information on specific absorption rate allowing to previously develop RF coils and their possible effects on the biological sample.