温度对金属紧固件与碳纤维／环氧复合材料的电偶腐蚀影响的研究

应用电化学方法研究了碳纤维/环氧复合材料与TC6钛合金、LC4铝合金、30CrMnSiNi2A合金钢的电偶腐蚀行为。在20～60℃温度范围内研究了温度对各偶对的电偶电位及电偶电流的影响。比较了各种紧固件金属材料与碳纤维复合材料构成偶对时的电偶腐蚀性能。     

碳纤维环氧复合材料与金属电偶腐蚀的研究进展

综述了碳纤维环氧复合材料与金属电偶腐蚀与控制方法的研究进展，着重介绍了碳纤维环氧复合材料的基本特点，碳纤维复合材料与金属电偶腐蚀行为、现代表现分析技术在复合材料电偶腐蚀研究中的应用，对防止电偶腐蚀的防护措施与理论进行了初步的探讨。     

钛合金的电偶腐蚀与防护

总结了不同牌号的钛合金与铝合金、钢、复合材料接触时产生电偶腐蚀的敏感性.结果表明:钛合金与铝合金和结构钢接触时会产生不同程度的电偶腐蚀,必须进行防护处理方可使用;钛合金与不锈钢接触在常温下可直接接触使用,但在高温下,其电偶腐蚀行为可能发生变;钛合金与炭纤维复合材料可直接接触使用.表面处理作为一种补充防护措施,可在一定程度上降低钛合金与铝合金、结构钢之间的电偶腐蚀的敏感性,但不能完全阻止,表面处理后进行喷涂防护涂层、密封等防护措施可进一步降低电偶腐蚀敏感性.     

TA7钛合金/耐热不锈钢电偶腐蚀敏感性研究

依据航空标准评价了ＴＡ７钛合金和１Ｃｒ１１Ｎｉ２Ｗ２ＭｏＶ及Ｃｒ１７Ｎｉ２耐热不锈钢在３．５％ＮａＣｌ水溶液中的电偶腐蚀敏感性,研究了试样表面状态对电偶腐蚀行为的影响,探讨了腐蚀机理。结果发现,有关文献中材料的常规接触腐蚀数据不适合于压气机工况下的材料接触相容性设计,航标中的平均电偶电流密度指标不适合作为评价钝性材料接触腐蚀敏感性的判据。     

钢芯铝绞线中的电偶腐蚀行为

钢芯铝绞线中不同金属接触容易产生电偶腐蚀.通过测量Fe和Al分别与纯Zn、镀Zn、5%Al-Zn合金、2%Mg-Zn合金、55%Al-Zn合金在1 mol/L NaCl溶液中的电偶电流,判断不同金属接触时的腐蚀程度,从而选择钢芯镀层,达到最佳匹配,减轻电偶腐蚀.结果表明:Fe与55%Al-Zn合金镀层的电偶电流最小,腐蚀程度最轻;含Mg的热镀Zn层与Al形成的电偶比纯热镀Zn层与Al形成的电偶的腐蚀程度轻.     

镁合金电偶腐蚀研究及其进展

研究了镁合金AM60与异种金属Q235碳钢、18-8不锈钢、LY12铝合金和纯铝之间的电偶腐蚀,介绍了镁合金电偶腐蚀的最新研究进展,重点探讨了影响镁合金电偶腐蚀的因素和减轻镁合金电偶腐蚀的措施,最后提出了镁合金电偶腐蚀研究中需要解决的科学问题.研究和讨论分析表明,为防止镁合金电偶腐蚀,应全面而系统地进行合理的结构设计、选择合适的匹配材料、在镁合金和异种金属表面分别涂装性能优良的耐碱性涂层体系.由于镁腐蚀发生碱化,所以防止电偶腐蚀的环境应避免选用含铝涂层体系.     

压铸镁合金在防冻液中的电偶腐蚀规律研究

研究了压铸AZ91D镁合金分别与A3钢、H62黄铜、LF21铝合金及356号铸铝偶接后在80 ℃汽车防冻液中的电偶腐蚀行为及规律.自然腐蚀电位、电偶电位和电偶电流的测量结果表明,压铸AZ91D镁合金在与上述4种材料构成的电偶对中始终是阳极,且电偶腐蚀的阳极过程在该体系中受到较大的阻滞.电偶腐蚀效应的分析结果表明AZ91D与4种材料偶接后其阳极溶解速度较其未偶接前上升不超过1个数量级,且4种电偶对的电偶腐蚀效应存在如下相对关系:γ356号铸铝＜γLF21＜γH62＜γA3.     

复合材料表面防护对LY12CZ铝合金电偶腐蚀的影响

应用电化学测量、ＡＳＴＭ ５％盐雾试验、周浸腐蚀和大气暴露试验，研究不同表面处理的复合材料对ＬＹ１２ＣＺ铝合金电偶腐蚀的影响。     

新型镍铝青铜的电偶腐蚀行为研究

海水泵阀等附件是海水管系的重要部件,国内常用锡青铜、硅黄铜制造,与目前推广使用的B10合金在海水中偶合时,电偶腐蚀较重,不能满足海水管系对高可靠性的要求.为此,研制了一种与B10海水管道材料配套使用的海水泵、阀材料.通过测量研制合金及常用泵阀材料与B10、B30等管道材料偶合时的电偶电流、电偶电位和电偶腐蚀率等参量,研究了新研制的合金在海水中的电偶腐蚀行为.     

高温合金/NiAl封严涂层的电偶腐蚀行为研究

采用空气等离子喷涂工艺在高温合金基体上制备了NiAl封严涂层。研究了NiAl涂层/高温合金在5%(质量分数)NaCl溶液中的电偶腐蚀行为,结合极化曲线、开路电位和SEM形貌检测,探讨封严涂层的腐蚀机理。结果表明,高温合金基体与NiAl涂层的电偶电流密度为2.1356μA/cm2,电位较负的NiAl涂层作为电偶对的阳极,腐蚀更严重,腐蚀产物疏松呈絮状覆盖在涂层表面。等离子喷涂的NiAl涂层含有较多的孔隙和氧化物,腐蚀容易在缺少氧化物覆盖的区域发生。NiAl涂层边缘的氧化物也容易优先溶解,形成腐蚀产物膜,堵塞涂层微孔,抑制腐蚀的进行。随着腐蚀时间延长,NiAl涂层的防护性能逐渐减弱。     

复合材料对30CrMnSiA接触腐蚀的研究

通过电化学测量、盐雾试验、周浸试验、机械和疲劳性能测试及应力腐蚀试验,研究了碳纤维环氧复合材料与30CrMnSiA钢的接触腐蚀特性。其结果表明:30CrMnSiA钢与碳纤维环氧复合材料之间存在严重的接触腐蚀,但不影响30CrMnSiA的应力腐蚀性能。文中还给出了防止碳纤维环氧复合材料与30CrMnSiA接触腐蚀的防护措施。     

全钛冷凝器主循环水系统的电偶腐蚀及其防护

由于钛合金在海水中的优良耐蚀性，现代舰船主循环水系统日益趋于采用全钛冷凝器。但采用全钛冷凝器后，对冷却水系统中其它结构材料将产生电偶腐蚀作用。本文通过电偶腐蚀试验和系统腐蚀试验，查明了这种影响，并提出了防止钛合金对其它电位较负材料产生的电偶腐蚀作用的措施。     

Stress-Corrosion Cracking and Galvanic Corrosion of Internal Bolts from a Multistage Water Injection Pump

Nineteen out of 26 bolts (studs) used for assembly of multistage water pump showed severe corrosion and cracking after brief service in a severe working environment that contained saline water, CO₂, and H₂S. The failed bolts and intact nuts were supposed to be made out of a special type of austenitic stainless steel as per ASTM A 193 B8S and ASTM A 194, respectively. However, the investigation showed that bolts and nuts are made from two different alloys: an austenitic stainless steel and a nickel-base alloy. The difference in the corrosion resistance of these two alloys led to severe galvanic corrosion. The galvanic coupling between bolts and nuts in addition to the severe working environment played major role in the premature failure of bolts. The mechanisms of bolt failure were galvanic corrosion for bolts that were in direct contact with the environment and stress-corrosion cracking in the bolts remote from the severe environment. The stress-corrosion cracking was influenced by a bad fit between the bolts and nuts threads. This resulted in a crevice and the development of an aggressive chemistry between the engaged bolt/nut threads. All factors required to cause stress-corrosion cracking were available, namely, stressed bolts (bolts under tensile stress), temperatures above 60 °C, and chloride ions.     

Boundary Element Method (BEM) Analysis for Galvanic Corrosion of Hot Dip Galvanized Steel Immersed in Seawater

A numerical analysis of galvanic corrosion of hot-dip galvanized steel immersed in seawater was presented.The analysis was based on the boundary element methods (BEMs) coupled with Newton-Raphson iterative technique to treat the nonlinear boundary conditions, which were determined by the experimental polarization curves. Results showed that galvanic current density concentrates on the boundary of steel substrate and zinc coating, and the sacrificial protection of zinc coating to steel substrate results in overprotection of steel cathode. Not only oxygen reduction but also hydrogen reduction could occur as cathode reactions, which probably led up to the adsorption and absorption of hydrogen atoms. Flat galvanized steel tensile sample shows a brittle behavior similar to hydrogen embrittlement according to the SSRT (show strain rate test) in seawater.     

Ultrasonic Approach of Rayleigh Pitch-catch Contact Ultrasound Waves on CFRP Laminated Composites

CFRP （carbon fiber reinforced plastics） composite materials have wide applicability because of their inherent design flexibility and improved material properties. However, impacted composite structures have 50%-75% less strength than undamaged structures. In this work, a CFRP composite material was nondestructively characterized in order to ensure product quality and structural integrity of CFRP and one-sided pitch-catch technique was developed to measure impacted-damaged area by using an automated-data acquisition system in an immersion tank. A pitch-catch signal was found to be more sensitive than normal incidence backwall echo of longitudinal wave under defect conditions in the composite.     

NaCl溶液中Zn－Al－Cd合金的接触腐蚀研究

研究了作为牺牲阳极材料的Ｚｎ－Ａｌ－Ｃｄ合金在ＮａＣｌ溶液中与Ａ３钢、３０２不锈钢和纯铜偶接时的接触腐蚀行为，探讨了溶液中Ｃｌ－浓度变化，以及电偶对中阴极金属材料和阴阳极面积比Ａｃ／Ａａ不同时对电偶电流密度ｊＺｎｇ和电偶电势Ｅｇ的影响。结果表明，电偶对中阴极金属材料不同，ｊＺｎｇ随Ｃｌ－浓度增大有不同的变化趋势；ｊＺｎｇ与Ａｃ／Ａａ成正比关系；Ｃｌ－浓度变化对Ｅｇ的影响较大，而大多数浓度下阴极金属材料和阴阳极面积比不同对Ｅｇ的影响较小     

Effects of temperature on impact damages in CFRP composite laminates

In this paper, the effect of temperature variations (low and high temperatures) was studied experimentally on impact damage to CFRP laminates. The composite laminates used in this experiment were CF/EPOXY orthotropic laminated plates with lay-up [0₆/90₆]_s and [0₄/90₄]_s, and CF/PEEK orthotropic laminated plates with a lay-up of [0₆/90₆]_s. A steel ball launched by the air gun was used to generate the CFRP laminate impact damage. For impact-damaged specimens, nondestructive evaluation (NDE), such as a scanning acoustic microscopy (SAM) was performed on the delamination-damaged samples to characterize damage growth at different temperatures.

Therefore, this study was undertaken to experimentally determine the interrelations between impact energy and impact damage (i.e. the delamination area and matrix) of CFRP laminates (CF/EPOXY and CF/PEEK) subjected to foreign object damages (FOD) at low and high temperatures.     

电镀锌钢板上氟锆酸盐协同硅烷复合膜的结构与耐腐蚀性能

为了提高电镀锌板硅烷膜的耐腐蚀性能,采用氟锆酸盐协同硅烷的无枳／有机复合法在自制电镀锌钢板上制备了硅烷复合膜。通过SEM测试了硅烷复合膜的形貌,采用FTIR和XPS分析了复合膜的结构及元素组成,用中性盐雾试验测试了复合膜的耐蚀性能,并讨论了复合膜的成膜及耐蚀机理。结果表明：硅烷复合膜是由Si-O-Si等共价键形成的三维...     

先进复合材料的声学特性及其在水声工程中的应用

通过理论计算及试验，研究了碳纤维增强复合材料（ＣＦＲＰ），芳纶纤维增强复合材料（ＫＦＲＰ）的基本声学性能，分析了其作为水声结构材料在水声工程中应用的可能性及其特点。尤其指出了先进复合材料作为声纳导流罩透声窗材料的现实意义。