3.5%NaCl腐蚀环境下2种航空铝合金材料疲劳性能试验研究

腐蚀环境下的疲劳性能是航空金属结构疲劳寿命设计的重要前提,为此,试验测定了2种航空铝合金材料（2E12-T3、7050-T7451）的光滑试样和缺口试样在干燥大气和3.5%NaCl腐蚀环境下的疲劳性能,在试验数据的基础上进行性能对比,并对试样断口进行扫描电镜（SEM）分析,研究了3.5%NaCl腐蚀环境与载荷联合作用对腐蚀疲劳性能的影响机理,研究结果表明:3.5%NaCl腐蚀环境对2种铝合金材料的疲劳性能均产生不利影响,且腐蚀与疲劳载荷的交互作用随着应力水平的降低而增强,疲劳性能下降更明显;与光滑试样相比,腐蚀环境对铝合金2E12-T3缺口试样疲劳性能的影响更大,但对铝合金7050-T7451缺口试样疲劳性能的影响却变小;在腐蚀环境下,裂纹尖端易发生电化学反应产生腐蚀产物和[H]离子,腐蚀产物的存在会阻碍裂纹闭合,同时,[H]离子导致裂纹尖端的氢脆效应,加快裂纹扩展,使疲劳性能降低。     

An investigation on electroless Cu–P composite coatings with micro and nano-SiC particles

Cu–P/micro-SiC and Cu–P/nano-SiC composite coatings were deposited by electroless plating and their composition and microstructure were observed by EDX (energy-dispersive analysis), SEM (scanning electron microscope) and XRD (X-ray diffraction). The corrosion resistance, microhardness and the wear resistance of the Cu–P/nano-SiC composite coatings were measured and the comparison with those of Cu coatings and Cu–P/micro-SiC coatings were given. The anti-corrosion properties of Cu coatings were investigated in 3.5% NaCl solution by the potentiodynamic polarisation and electrochemical impedance spectroscopy (EIS) techniques. Among three kinds of Cu–P based coatings, the corrosion resistance, hardness and wear resistance of Cu–P/nano-SiC coatings were the largest. This indicates that the precipitation of nano-SiC particles would improve the corrosion resistance, hardness and wear resistance of the Cu–P coatings significantly.     

静电喷涂聚酰亚胺涂层的防腐蚀性能

聚酰亚胺(PI)在防腐蚀方面前景良好,但目前国内报道不多。采用静电喷涂的方法在N80钢表面制备了一种聚酰亚胺防腐蚀涂层。通过盐雾试验、浸泡试验评价了涂层在不同腐蚀环境中的耐蚀性能;通过硬度测试和抗冲击试验评价了涂层的力学性能;采用红外光谱、电化学方法交流阻抗、扫描电镜(SEM)、能谱(EDS)等方法研究了涂层的失效过程。结果表明:涂层耐盐雾性能良好,3 080 h盐雾试验后仅表面发生微观物理破坏,在人工划痕处产生少量腐蚀产物;涂层在3.5%NaCl溶液和25%HCl溶液中耐蚀性能优异,电化学性能不随时间发生显著变化,但在涂层表面产生少量微观缺陷;涂层力学性能良好,但提高腐蚀介质温度会使得力学性能下降。     

OP1O对镁合金表面钒酸盐转化膜的耐蚀改性研究

为了研究非离子表面活性剂OP10对镁合金表面钒酸盐转化膜形成过程中气泡黏附的影响,通过接触角测量仪、扫描电镜及能谱仪、电化学测试和中性盐雾试验等对镁合金转化试样表面的接触角、元素组成及耐蚀性进行了测试分析.结果表明:与未加OP10转化液处理的镁合金样品相比,加入OP10处理过的试样固液接触角从43.48°减小到5.66°,O、S元素含量增加,腐蚀电位正移了280 mV,腐蚀电流密度降低了98％,中性耐盐雾时间从72h增加到140 h,镁合金的耐蚀性能显著提高.     

超疏水高疏油铝滤网的制备及其耐腐蚀性能

目前针对抽油烟机铝滤网的黏附油烟及腐蚀性问题等研究较少。利用Fe Cl3溶液刻蚀并沸水处理铝滤网,并采用十七氟癸基三甲氧基硅烷对其表面进行改性,制备出具有超疏水高疏油表面的铝滤网。利用扫描电子显微镜、原子力显微镜、X射线衍射仪、傅里叶变换红外光谱仪对滤网的表面形貌和成分进行了分析,用接触角测量仪对试样的润湿性能进行了测量,用电化学工作站对试样的耐腐蚀性能进行了研究。结果表明,在铝滤网表面制备出了微纳米复合结构,对去离子水、丙三醇、二甘醇、大豆油的接触角分别达151. 00°、148. 00°、143. 00°、140.75°,对去离子水、丙三醇、大豆油的滚动角分别为1°、5°、15°,处理后的铝滤网在自然环境和高温环境中具有优异的稳定性,电化学测试表明其具有更好的耐腐蚀性能,在3.5%Na Cl溶液中的缓蚀率达85.8%。     

Multifunctional superhydrophobic coatings fabricated from basalt scales on a fluorocarbon coating base

Superhydrophobic coatings are increasingly being evaluated as anticorrosion interventions in exceed-ingly hydrated environments.However,concerns about their long-term durability and amenability to large-area applications in marine environments are still hindering commercial-scale deployment.This study is focused on development of easy-to-apply superhydrophobic coatings,with multifunctional capa-bilities,in order to extend the integrity and durability of the coatings in harsh marine environments.Here,a set of facile methods involving selective chemical etching using concentrated NaOH,as well as fluori-nation with perfluoropolyether methyl ester were adopted to fabricate a superhydrophobic surface on basalt scales,having the required rough hierarchical micro-nanotextured and low surface energy.The superhydrophobic basalt scales were subsequently aligned atop a fluorocarbon resin,pre-deposited on a metal substrate,to yield a multifunctional superhydrophobic coating(3 μL water droplet;contact angle=165.1°,rolling angle=0.7°),easily amenable to large surface area application and having excellent wear resistance,UV-aging resistance,salt spray resistance,corrosion resistance and antibacterial capabilities.     

2A12铝合金基体超疏水表面制备及性能研究

铝合金在使用过程中极易引发基体腐蚀现象,如点蚀、晶间腐蚀等,为保障铝合金在腐蚀环境中的应用,可通过建立超疏水表面改变铝合金表面的润湿性,从而在一定程度上减少腐蚀液与铝合金表面的接触,进而改善耐蚀性。本文通过酸刻蚀和沸水刻蚀两种方法在铝合金表面构筑微纳米结构,并使用低表面能物质硬脂酸进行表面处理得到超疏水表面。采用扫描电子显微镜、接触角测试仪、原子力显微镜分别对铝合金表面形貌、疏水性和粗糙度进行测试,得到两种方法的最佳制备时间,而后通过极化曲线对两种方法制备的铝合金表面耐蚀性能进行对比,进而研究两种刻蚀方法对铝合金耐蚀性的影响。实验结果表明：酸刻蚀时间为15 s时,铝合金表面接触角达到峰值163.9°,呈现超疏水状态,相对于空白样品,表面粗糙度增加了24倍,电化学自腐蚀电位正向移动0.362 8 V;沸水刻蚀时间为1 min时,其表面接触角达到峰值109.6°,比空白样品疏水性强但未呈现超疏水状态,相对于空白样品,经沸水刻蚀的铝合金表面粗糙度增加了4.4倍,电化学自腐蚀电位正向移动0.074 8 V。两种方法处理得到的铝合金表面的耐蚀性与空白铝合金试样相比均有显著提高,而酸刻蚀法的缓蚀效...     

阳极氧化法制备铝基超疏水涂层及其稳定性和耐蚀性的研究

铝由于在潮湿的环境中很容易受到污染和损坏,从而严重影响了其美观性和用途。为了改善铝基材料的耐腐蚀性能,采用电化学阳极氧化法与十四酸修饰相结合的方式在铝基底上制备了超疏水涂层。通过场发射扫描电镜(FESEM)和X射线能量色散光谱(EDS)对涂层表面形貌和化学组成进行了表征。同时利用接触角测量仪、喷砂实验和电化学测试分别对涂层表面的润湿性、机械稳定性以及耐腐蚀性能进行了研究。结果表明:当阳极氧化电压为20V时,所制备的涂层为最佳铝基超疏水涂层,此时涂层的接触角为(155.2±0.5)°,滚动角为(3.5±1.3)°。其对应的腐蚀电流密度较铝基底降低了2个数量级,腐蚀电位从-0.629V正移到-0.570V,呈现出优异的耐腐蚀性能。此外,该涂层还具有良好的机械稳定性。     

Ni-P/纳米SiC复合镀层的电化学行为及耐蚀性能

为了深入研究纳米SiC对Ni-P电镀层在NaCl溶液中的电化学行为的影响,电沉积制备了Ni-P/纳米SiC复合镀层。采用扫描电子显微镜(SEM)观察了镀层的微观形貌,利用动电位极化曲线和交流阻抗技术研究了Ni-P/纳米SiC复合镀层在3.5%NaCl溶液中的电化学行为。结果表明:经过24 h浸泡,非晶Ni-P镀层和Ni-P/SiC2复合镀层在3.5%NaCl溶液中具有较高的电荷转移电阻,表现较好的耐蚀性;Ni-P/SiC20复合镀层在NaCl溶液中随着浸泡时间的延长,Nyquist谱半圆弧减小,因而镀层耐蚀性较差。     

MgO纳米颗粒对AZ31B镁合金微弧氧化涂层耐磨和耐蚀性的影响

为了进一步改善AZ31B镁合金的耐磨和耐蚀性能,采用微弧氧化技术且在电解液中添加质量浓度为4g/L的MgO纳米颗粒,制备了氧化物陶瓷膜。采用扫描电子显微镜观察其表面和截面形貌,采用X射线衍射仪测试微弧氧化(MAO)膜的物相组成,利用电化学工作站,盐雾试验箱测试耐腐蚀性,利用球-盘磨损实验测试耐磨性。结果表明:添加MgO纳米颗粒后,膜层孔洞的填充,膜层成分中MgO含量的增加,使腐蚀电流密度降低至4.28×10~(-9) A/cm~2;中性盐雾试验结果表明腐蚀以点蚀和裂纹的形式发生,MgO的嵌入使腐蚀点减少和内部致密层厚度增加,从而使2N荷载、干摩擦条件下样品的摩擦系数和磨损率分别减小至0.228和1.39×10~(-5) mm~3/(N·m),耐蚀性和耐磨性得到改善。     

J55油管钢抗CO_2腐蚀复配缓蚀剂的制备及其缓蚀性能

目前,对油田常用油管材料J55钢抗CO_2腐蚀复配缓蚀剂研究不足,以油酸咪唑啉季铵盐和喹啉季铵盐为缓蚀剂主剂,配以辅助剂和表面活性剂配制了3种复配缓蚀剂,利用失重试验、扫描电子显微镜测试和电化学测试研究了3种复配缓蚀剂在油田采出水介质中对J55油管钢的缓蚀性能。结果表明:这3种复配缓蚀剂均有良好的抗CO_2腐蚀效果,其中喹啉季铵盐与硫脲复配缓蚀效果最好,高压失重试验中,缓蚀剂浓度为100 mg/L时缓蚀率可达85%以上,常压电化学测试中,缓蚀剂浓度为40 mg/L时,缓蚀剂可达97.91%;油酸咪唑啉季铵盐与硫脲复配、喹啉季铵盐与硫脲复配的缓蚀剂为抑制阳极型缓蚀剂,喹啉季铵盐与六亚甲基四胺复配的缓蚀剂为混合型缓蚀剂。     

A100钢镀Cr防护技术在海洋环境下的腐蚀行为研究

通过海南户外暴露实验研究了A100钢表面镀铬层的腐蚀行为.使用扫描电镜观察了腐蚀后镀层的表面和截面形貌,利用交流阻镜技术表征了镀层在不同腐蚀阶段的特征;并讨论了腐蚀对力学性能的影响.结果表明:镀层表面存在的显微裂纹是腐蚀发生、发展过程中的主要影响因素,腐蚀对镀层力学试样的力学性能影响很大,导致抗拉强度降低,断口呈脆性断...     

Preparation and corrosion behavior of Ni and Ni–graphene composite coatings

The graphite oxide was synthesized using the Hummers method, and then it was reduced by hydrazine hydrate to obtain graphene. It was characterized with UV (ultra violet), IR (infra red), XRD (X-ray diffraction) spectra and SEM (scanning electron microscope) images. The composite coating of Ni–graphene on mild steel specimens was obtained by the electrodeposition technique. The composite coating was subjected to various electrochemical tests to know its corrosion behavior and compared with pure Ni coating. The EIS (electrochemical impedance spectroscopy) was performed to confirm the corrosion resistance property. The composite film was studied by recording its XRD and SEM. The crystallite size, texture coefficients and hardness of coating was measured.     

聚丙烯腈填充聚四氟乙烯复合材料摩擦磨损性能研究EI

用机械共混、冷压成型和空气中烧结的方法制备了不同质量分数的聚丙烯腈填充聚四氟乙烯制品。用MM-200摩擦磨损试验机测试不同样品在干摩擦下的摩擦学行为;用扫描电子显微镜和光学显微镜对几种样品的磨损面、磨屑和转移膜进行观察和分析。结果表明,聚丙烯腈的加入,不但使聚四氟乙烯的磨损量大幅降低,而且还使其摩擦系数有所降低。通过扫描电子显微镜观察发现填充聚丙烯腈的聚四氟乙烯样品的对磨面有完整而且不易脱落的转移膜,这是其具有良好耐磨性的主要原因。     

Investigation on the mechanical properties and frictional performance of Ni–Cu–Si alloy

The microstructure evolution, mechanical properties and dry sliding behaviour of Ni–30Cu–xSi alloy have been investigated systematically. As the volume fraction of microscale second-phase particles and nanoscale precipitates increases, the hardness, yield strength and ultimate tensile strength of alloy are improved significantly but elongation is reduced. Through confocal laser scanning microscope and atomic force microscope, it is suggested that the wear mode changes from the mixture of abrasive and adhesive wear to single abrasive wear. Owing to the existence of netlike microscale second-phase particles which are more likely to split the matrix, the Ni–30Cu–5.5Si alloy exhibits an abnormal higher wear rate even with the highest hardness. The netlike structure which deteriorates the friction performance should be avoided in wear-resistant materials.     

多道搭接激光熔覆NiCrBSi合金层组织及性能

为了改善40Cr钢的表面状态,拓展其应用范围,采用CO2激光器及LASERCELL-1005六轴六联动三维激光加工机床在40Cr钢表面多道搭接激光熔覆了NiCrBSi合金粉末,利用扫描电镜、金相显微镜、磨损试验机、盐雾试验机等对熔覆层的组织及性能进行了研究.结果表明:激光熔覆层由熔覆区、结合区和热影响区3部分组成.多道...     

离焦量对激光熔覆层组织及性能的影响

目的改善40 Cr钢表面性能,提高其表面硬度、耐磨性及耐蚀性。方法利用扫描电子显微镜、显微硬度计、磨损试验机、电化学测试系统等对激光熔覆层组织及性能进行观察和分析。结果离焦量越大,熔覆粉末及基体表面熔化深度越浅,通过控制适当的离焦量可以获得结合良好的涂层;离焦量为110 mm时,激光束的快热快冷作用能获得细小均匀的组织,细晶能保证较高的硬度,耐磨性及耐蚀性均较好。结论 40Cr钢经激光熔覆处理后可显著改善其表面性能,适宜的离焦量有利于获得最佳性能。     

放电等离子烧结NdFeB磁体的氧化和腐蚀行为

采用放电等离子烧结技术制备了新型NdFeB磁体,研究了NdFeB磁体在湿热环境下的氧化行为和在电解质溶液中的电化学特性.在扫描电子显微镜下分析了磁体的显微组织结构和成分.结果表明,与传统烧结NdFeB磁体相比,新型磁体的显微组织特征为:主相Nd2Fe14B晶粒细小、均匀,富钕相在主相晶粒边界上分布较少,主要集中在三角晶界处.这种组织结构有效抑制了磁体沿富钕相发生的晶间腐蚀的过程,使磁体具有良好的耐腐蚀性能.     

Rapid fabrication of large-area, corrosion-resistant superhydrophobic Mg alloy surfaces

A superhydrophobic magnesium (Mg) alloy surface was successfully fabricated via a facile electrochemical machining process, and subsequently covered with a fluoroalkylsilane (FAS) film. The surface morphologies and chemical compositions were investigated using a scanning electron microscope (SEM) equipped with an energy-dispersive spectroscopy (EDS) and a Fourier-transform infrared spectrophotometer (FTIR). The results show hierarchal rough structures and an FAS film with a low surface energy on the Mg alloy surfaces, which confers good superhydrophobicity with a water contact angle of 165.2° and a water tilting angle of approximately 2°. The processing conditions, such as the processing time and removal rate per unit area at a constant removal mass per unit area, were investigated to determine their effects on the superhydrophobicity. Interestingly, when the removal mass per unit area is constant at approximately 11.10 mg/cm(2), the superhydrophobicity does not change with the removal rate per unit area. Therefore, a superhydrophobic Mg alloy surface can be rapidly fabricated based on this property. A large-area superhydrophobic Mg alloy surface was also fabricated for the first time using a small-area moving cathode. The corrosion resistance and durability of the superhydrophobic surfaces were also examined.     

含磷石墨烯的制备及复合涂层的耐蚀性能

以植酸(PhA)为原料,采用热解法制备含磷石墨烯(PhA-G),并以硅树脂(SiR)为成膜物制备含磷石墨烯/硅树脂(PhA-G/SiR)复合防腐蚀涂层。通过拉曼光谱和XPS分析含磷石墨烯的结构,通过SEM、TEM和AFM观察含磷石墨烯的形貌,通过接触角、吸水率、电化学阻抗谱、极化曲线和盐雾实验等研究复合涂层的耐蚀性能。结果表明：相比于纯SiR涂层和氧化石墨烯/硅树脂(GO/SiR)复合涂层,PhA-G/SiR复合涂层对金属的保护作用更好;当含磷石墨烯添加量为3%(质量分数)时,PhA-G/SiR复合涂层表现出较好的疏水性和优异的防腐蚀性能,其接触角为103.5°,吸水率为3.72%;腐蚀电流密度为3.53×10^-10 A/cm²,电化学阻抗值达到3.82×10⁷ Ω·cm²,耐盐雾达到960 h。