ET-98无机磷酸盐富锌涂料的性能与应用

论述了国内首创的ET-98无机磷酸盐富锌涂料，该涂料克服了无机磷酸富锌涂料、无机富锌涂料喷砂、抛丸的缺点，简易可行，除锈、除油后即可涂刷，并能达到较好的防腐效果。     

基于人工神经网络的铝熔体中氢的预测

用HyscanⅡ型测氢仪测定了铝熔体在不同温度和保温时间下的氢含量 ,通过对BP人工神经网络的分析和改进 ,采用了结构为 2 4 2 1的BP神经网络模型 ,用所获得的试验数据对其进行训练和测试 ,当BP神经网络经过 3× 10 5次学习后 ,最大训练误差 (MaxTrainingError)和训练均方差 (RMSTrainingError)分别为 0 .5 5 %和 0 .18% ,同时相应的最大测试误差 (MaxTestError)和测试均方差 (RMSTestTraining)分别达到了 0 .72 %和 0 .3 3 % ,对铝熔体中氢的预测达到了很高的精度 ,从而建立了熔炼条件 (温度、保温时间 )和氢含量的映射模型     

BEHAVIOUR AND MECHANISM OF STRESS CORROSION CRACKING FOR Al-Li-Cu-Mg ALLOY

Studies were made of the influence of aging conditions and applied potentials on thestress corrosion carcking(SCC)susceptibility for an Al-Li-Cu-Mg alloy by slow strainrate technique.The relationship between the relative hydrogen content on specimensurface,the applied potentials and elapsed time has also been examined.The SCCsusceptibility was found to be dependent on aging conditions in which the peak agedcondition gave the worst SCC resistance and the natural aged condition had the best one.The SCC susceptibility and surface hydrogen content relates to the applied potentials.The anodic potentials increase SCC susceptibility,while the cathodic ones below thecritical potential accelerate SCC.It is considered that both the anodic dissolution and     

波型与电位对A537钢疲劳裂纹扩展的影响

研究了A537钢在3.5%NaCl水溶液中阴极极化与阳极极化条件下加载波型对疲劳裂纹扩展速率的影响并研究了相应电位条件下应变电极的电化学响应规律,结果表明,在外加电位为-800mV(SCE)以上时阳极溶解机制起主导作用,在-800mV以下时氢脆机制起主导作用,在阳极极化条件下,持续应变型加载波型的影响主要体现于低△K范围,而在阴极极化条件下,其影响体现于高△K范围,持续应变导致了自腐蚀电位的下降与阳极溶解电流密度的大幅度提高     

压铸条件下过共晶铝硅合金P变质的必要性

在铝合金压铸生产过程中,Al-P中间合金变质处理和压力铸造工艺都能够使过共晶铝硅合金中的初晶硅晶粒细化.探讨Al-P中间合金变质处理,分别在压铸工艺条件下和普通金属型条件下,对过共晶Al-15Si合金组织的不同影响.试验表明,压铸条件下未经Al-P变质的和经Al-P变质的Al-15Si合金与金属型条件下未经Al-P变质的Al-15Si相比,初晶Si尺寸分别减小50%和75%左右;在相同的压铸工艺条件下,Al-P变质后Al-15Si合金初晶Si尺寸,比未经过Al-P变质的Al-15Si合金初晶Si尺寸减小40%左右.论证了在Al-Si系过共晶铝合金压铸件生产过程中,Al-P中间合金进行变质处理的必要性.     

低合金奥-贝球铁电弧焊焊条的研究

本文通过等温热处理系统地研究了Ｃｕ，Ｎｉ，Ｍｏ对球铁焊缝金属等温转变，奥－贝化能力及机械性能的影响，并利用Ｘ射线衍射仪，扫描电镜，透射电镜研究了低合金奥－贝球铁焊缝的基体结构，分析讨论了基强韧化机制。在此基础上首次研制成功了Ｎｉ－Ｍｏ低合金奥－贝球铁新焊条，与非合金化奥－贝球铁焊条相比，焊缝金属的奥－贝化能力提高２．５倍，其焊缝与焊接接头的机械性能均满足奥－贝球铁的要求。     

Al-P中间合金在Al-Si活塞合金中的应用

在实验室和生产条件下研究了Al-P中间合金对共金和过共晶Al-Si活塞合金的变质工艺特点，变质效果和力学性能等的影响，结果表明：使用Al-P中间合金操作简单，变质效果好且稳定，力学性能也比其他变质剂有不同程度的提高；使用该中间合金无渣，无污染，从时间上看可以完全省去变质处理过程，节约能源，提高合金的实收率，降低铝耗，有着良好的应用前景。     

超高纯铁素体不锈钢在3．5％NaCl中的腐蚀疲劳的裂纹萌生

本文利用三电极技术研究了超高纯铁素体不锈钢Ｆｅ－２６Ｃｒ－１Ｍｏ在３．５％ＮａＣｌ水溶液转化体系中，低周腐蚀疲劳的裂纹萌生行为．在静态点蚀电位以下，形变诱发点蚀出现，但是点蚀在本文的研究体系不是导致裂纹萌生的原因．在低应变速率下，裂纹沿晶内的驻留滑移带萌生，且沿滑移带的电化学溶解加快了裂纹萌生．在高应变速率下，裂纹在晶界萌生，且沿晶界有点蚀实验结果表明，电化学溶解加速了裂纹萌生，点蚀在此钝化体系中不是裂纹萌生的机制．应变速率影响裂纹萌生方式．     

Al—Li—Cu—Mg合金应力腐蚀性能及机理研究

利用恒应变速率方法研究了Al—Li—Cu—Mg合金的应力腐蚀开裂,包括时效条件及外加电位对应力腐蚀的影响,同时研究了试样表面相对氢浓度与外加电位及应力腐蚀时间的关系,实验结果表明,合金的应力腐蚀性能取决于时效条件,其中峰时效条件下最差,自然时效条件下最好,应力腐蚀敏感性及试样表面氢浓度与外加电位有关,阳极电位增加应力腐蚀敏感性,阴极电位低于临界电位时加速应力腐蚀,认为合金在应力腐蚀过程中阳极溶解与氢脆机制联合作用。     

Design and fabrication of a resonant pressure sensor by combination of DETF quartz resonator and silicon diaphragm

A new type of resonant pressure sensor is presented which is realized by combination of a double-ended tuning fork (DETF) quartz resonator and a silicon diaphragm. To examine the feasibility and investigate the performance of this innovation, theoretical analysis and finite elements method are employed to optimize the structure parameters. Micromachining technology are involved in the fabrication of the silicon diaphragm and the DETF quartz resonator, which are fabricated separately and bounded together afterwards. Performances of the sensor prototypes are experimentally investigated. Preliminary testing results demonstrate that the sensor features a high sensitivity of approximately 452.5 Hz/kPa in the operating range of 0–6 kPa at room temperature, with a non-linearity <0.035 % FS and a hysteresis of 0.055 % FS. In addition, the maximum zero-drift is about 0.5 Hz/h which reveals favorable frequency stability. Thus, the feasibility of this scheme is verified. Due to the excellent performances such as high accuracy, high sensitivity, low cost and simple fabrication, this novel resonant sensor provides a commendable solution for low pressure measurement.