镁合金表面等离子喷涂Al涂层的耐腐蚀性能

采用等离子喷涂技术在AZ31镁合金表面制备Al涂层,测试了镁合金及Al涂层试样的极化曲线,研究了没有涂层的镁合金、经封孔处理和未经封孔处理的Al涂层镁合金3种试样在浸泡腐蚀和5%NaCl盐雾腐蚀情况下的耐腐蚀性能及其腐蚀行为。结果表明,经封孔处理的Al涂层试样在上述腐蚀条件下的耐腐蚀性均优于镁合金和未封孔处理的试样,在浸泡实验中未封孔处理的涂层试样比镁合金腐蚀更加严重,在盐雾实验中却优于镁合金。     

热浸镀锌层在中性盐雾试验中的防腐性能研究

采用2种定制的热浸镀锌试件,经5000 h中性盐雾试验后发现镀层防腐性能存在显著差异.采用镀锌层厚度损耗测试法、X射线衍射分析法（XRD）和扫描电镜分析法（SEM）分别测试了镀层的厚度损耗量、盐雾试验前后的晶体物质组成和腐蚀前后的微观形貌.研究表明:2种热浸镀锌试件在盐雾腐蚀过程中的产物和机理相似,而影响其防腐性能的主要因素为热浸镀锌的生产工艺、腐蚀产物的致密程度.     

TiO2基纳米容器的制备及抗腐蚀性能

采用NaF刻蚀法和溶胶凝胶法合成了二氧化钛@二硫基噻二唑@二氧化硅（TiO2@DMTD@SiO2）纳米容器。利用X射线衍射（XRD）、傅里叶变换红外光谱仪（FTIR）、扫描电子显微镜（SEM）等对纳米容器的微观形貌和结构进行了表征，采用视频光学接触角测量仪测试了涂层的亲水性，并通过电化学测试了涂层的耐腐蚀性能。结果表明，掺杂TiO2纳米容器的环氧树脂涂层接触角最大，其接触角为71.9°，并且与空白涂层相比，在质量分数3% NaCl溶液中浸泡1~7 d后，具有更高的耐腐蚀性能。     

等离子喷涂TiO2-CeO2复合涂层的结构及抗菌性能研究

利用等离子喷涂技术在医用Ti合金表面制备TiO2-CeO2复合涂层.采用X射线衍射仪(XRD)和扫描电子显微镜(SEM)对复合涂层进行表征.研究CeO2含量对复合涂层的接触角、表面粗糙度、耐腐蚀和抗菌性能的影响.结果表明,TiO2-CeO2复合涂层主要由金红石型TiO2和少量的锐钛矿型TiO2组成.CeO2的掺杂使得涂层表面具有微米级粗糙度并保持良好的亲水性,且使涂层的耐腐蚀性能得到提高.CeO2的掺杂可提高复合涂层对金黄色葡萄球菌的抑制能力,而对大肠杆菌则没有明显的抑制能力.     

镁合金电镀镍涂层的耐蚀性能

以化学镀镍作为保护层,对AZ91D镁合金进行直流电镀镍涂层以提高其耐腐蚀性能,并对镁合金表面两个不同厚度的镀镍涂层进行了比较.采用SEM对涂层的表面形态进行了研究.在X射线下纹理明显.镍涂层硬度约560VHN,远远高于AZ91D镁合金基底的硬度(约100VHN).电化学测量结果表明,在已经研究的镁合金涂层中,镍镀层有最低的腐蚀电流密度和最高的腐蚀电位.加速腐蚀实验中AZ91D镁合金镀镍具有很高的耐腐蚀性能.     

BNT无铅压电陶瓷体系的设计及制备工艺研究

本文采用传统陶瓷工艺,制备得到Bi0.5（Na1-x-yKxLiy）0.5TiO（3简称BNKLT）无铅压电陶瓷,运用X射线衍射、扫描电子显微镜对其进行了分析表征;通过压电、介电性能的对比,讨论了烧结温度对BNKLT陶瓷的影响;运用热分析及X射线衍射等手段,确定了粉体的热处理温度,并讨论了烧结温度对BNKLT陶瓷性能的影响;通过最终所得陶瓷的性能对比,确定制备的较优工艺参数。     

均相沉淀法制备Zn Fe2 O4负极材料及其储锂性能

采用均相沉淀法制备了ZnFe2 O4前驱体,探索了烧结温度对ZnFe2 O4结构和电化学性能的影响。用X射线衍射（XRD）和场发射扫描电子显微镜（FESEM）表征了材料的微观结构和形貌;采用循环伏安（CV）、电化学交流阻抗谱（EIS）和充放电测试了ZnFe2 O4作为锂离子电池负极材料的储锂性能。结果表明：随着烧结温度的升高,样品粒径增大;当烧结温度达到900℃时可以得到纯相尖晶石型ZnFe2 O4,其中在900℃下烧结的ZnFe2 O4样品具有最高的嵌锂活性、最好的电化学反应可逆性、最低的电化学反应阻抗和优良的倍率性能。     

Q235钢复合涂层腐蚀行为及微观组织研究

为探析舰船常用防护涂层的失效机制,制备了涂有环氧富锌底漆、环氧云铁中间漆和丙烯酸聚氨酯面漆的Q235钢板涂层试样,在盐雾下腐蚀1400h,用扫描电镜和能谱仪对涂层和基体金属表面的微观形貌、界面结构变化,表面缺陷,元素组成进行了研究.试验结果表明：盐雾腐蚀试验后,Q235钢表面涂层厚度增加,试样表面预制划痕处出现腐蚀,腐蚀产物呈片状,微观结构疏松,但涂层与基体在腐蚀后附着良好,涂层有良好的层间附着力,中间层和面层的防渗透性能保持在良好状态.     

可控气氛喷涂钛涂层及涂层电化学性能

为了研究在低度真空环境中所获得的钛涂层的组织和性能,以氩气为载气,在压力为0.4MPa、载气温度为室温、不同的喷涂条件下,用热喷涂方法在Q235钢基体上制备了钛金属涂层.经扫描电子显微镜（SEM）观察,发现在真空中用氩气为载气喷涂的钛涂层组织致密,缺陷与孔隙相对较少.x 射线衍射分析仪（XRD）分析表明,在空气中喷涂的钛涂层有较多的氧化物和氮化物;在真空中喷涂的钛涂层基本上没有氧化物和氮化物,其衍射图谱与纯钛十分接近;在空气中用氩气为载气喷涂的钛涂层含有一些氧化物,涂层中的缺陷和孔隙数量介于前两种状态之间.采用动电位极化法研究了在不同条件下热喷涂钛涂层的电化学腐蚀行为,并与纯钛试样进行比较.结果表明：在真空条件下喷涂的钛涂层腐蚀电位高于在空气中喷涂的钛涂层和在空气中用氩气为载气喷涂的钛涂层,但略低于纯钛的腐蚀电位.     

氯氧镁水泥混凝土中钢筋的腐蚀与防护试验研究

结合氯氧镁水泥混凝土耐水性,研究氯氧镁水泥混凝土中钢筋的腐蚀与防护,试验变量包括钢筋种类、混凝土保护层厚度和腐蚀龄期等。钢筋种类包括裸露钢筋和美加力涂层钢筋;混凝土保护层厚度包括25、50 mm;腐蚀龄期包括60、120、180、240、300、360 d。试验采用自来水长期浸泡至试块2/3处,并采用扫描电子显微镜（SEM）和能谱仪（EDS）对腐蚀后的钢筋微观结构和化学元素组成进行分析,研究钢筋的腐蚀机理。结果表明,通过软化系数分析,氯氧镁水泥混凝土的软化系数处于0.78～0.87,说明试验设计的氯氧镁水泥混凝土可用于干燥地区、受潮较轻地区或次要建筑结构。通过极化曲线及其电化学参数分析,裸露钢筋腐蚀速率为美加力涂层钢筋腐蚀速率的40～80倍,说明涂层防腐效果明显。     

Corrosion of carbon steel under epoxy-varnish coating studied by scanning Kelvin probe

The corrosion behavior of partly coated carbon steel was investigated by salt spray test and scanning Kelvin probe (SKP) in order to understand the long-term corrosion behavior of coated carbon steel in marine atmosphere environment. The localized corrosion was accurately characterized by SKP in both coated and uncoated regions. The SKP results showed that Volta potential varied with the test time, and the more the corrosion products, the more positive the potential. The borderline between coated and uncoated regions of partly coated steel shifted towards the coated side with the increasing of test time. The coating disbonding rate could be determined according to the shift of potential borderline measured by SKP. The corrosion mechanism of partly coated steel in NaCl salt spray was discussed according to the potential maps and corrosion morphologies.     

P-C法涂覆中碳结构钢的表面耐蚀性

应用Ｐ－Ｃ法对中碳结构钢进行Ｃｒ－Ｓｉ－Ａｌ复合涂覆,用电子探针及扫描电镜测定了涂层的表面成分及Ｃｒ,Ｓｉ,Ａｌ在涂层中的分布,用Ｘ射线衍测定了涂层中的相结构,将涂覆后的试样在酸、碱、盐溶液中进行腐蚀试验,结果表明,中碳结构钢经Ｐ－Ｃ法复合涂履后,表面优良的抗多种介质腐蚀的能力。     

40NiCrMo7钢表面锰系磷化膜的制备及耐蚀性

为了满足紧固件在工业中的实际应用,采用不同磷化工艺于40NiCrMo7钢表面制备了锰系磷化膜,并作为紧固件的表面腐蚀防护层.运用扫描电子显微镜、能谱仪、X射线衍射仪、盐雾腐蚀试验机与电化学测试系统对磷化膜的结晶组织、相结构及耐蚀性进行了研究.结果表明,磷化膜的主要相结构为MnHPO_4·2.25H_2O;在工艺Ⅱ条件下,锰系磷化膜组织均匀致密,且覆盖完整;磷化膜的腐蚀速率为0.018 mm/a,同时腐蚀防护率高达97.20%;经240h盐雾腐蚀试验后,磷化膜在工艺Ⅱ条件下的腐蚀面积仅为1%.     

Corrosion resistance of waterborne epoxy coating pigmented by nano-sized aluminium powder on steel

A novel kind of waterborne epoxy coating pigmented by nano-sized aluminium powders on high strength steel was formulated. Several coatings with different pigment volume content (PVC) were prepared. The coating morphology was observed using scanning electron microscopy (SEM), and the electrochemical properties were investigated by electrochemical impedance spectroscopy (EIS). Immersion test and neutral salt spray test were also conducted to investigate the corrosion resistance of the coating. It is demonstrated that the critical pigment volume content (CPVC) value is between 30% and 40%. The coating with PVC of 30% exhibits good corrosion resistance in 3.5% (mass fraction) NaCl solution.     

钢铁镀锌层纳米陶瓷转化膜的制备及性能

为了更深入地探讨钢铁镀锌层纳米陶瓷转化膜形成工艺以及对耐蚀性的影响,采用扫描电子显微镜（SEM）观察镀锌层的表面形貌,以及对涂层性能进行测试,结果表明,在镀锌层上形成很完整的纳米陶瓷转化膜;并且在形成纳米转化膜后与涂层具有有良好的结合力与耐腐蚀性能。     

Effects of laser heat treatment on salt spray corrosion of 1Cr5Mo heat resistant steel welding joints

The surface of 1Cr5 Mo heat-resistant steel welding joint was processed with CO2 laser, and the corrosion behaviors before and after laser heat treatment(LHT) were investigated in the salt spray corrosion environments. The microstructures, phases, residual stresses and retained austenite content of 1Cr5 Mo steel welding joint before and after LHT were analyzed with optical microscope and X-ray diffraction, respectively. The cracking morphologies and chemical compositions of corrosion products after salt spray corrosion were analyzed with field emission scanning electron microscopy(FESEM) and energy disperse spectroscopy(EDS), respectively, the polarization curves were measured on a PS-268 A type electrochemical workstation, and the mechanism of corrosion resistance by LHT was investigated as well. The results show that the passive film of original sample is destroyed owing to the corrosive media penetrating into the subsurface, resulting in the redox reaction. The content of residual austenite in the surface and the self-corrosion potential are increased by LHT, which is contributed to improving the capability of salt spray corrosion resistance.     

X70管线钢热浸渗铝处理后盐雾腐蚀行为

利用热浸渗技术对X70管线钢表面进行了渗铝处理,通过SEM和EDS观察了X70管线钢渗铝处理前后表面微观形貌和化学元素的变化,采用XRD分析了其盐雾腐蚀前后表面物相,研究了渗铝处理对X70管线钢盐雾腐蚀的影响。试验结果表明,盐雾腐蚀后未处理试样表面点蚀较为严重,热浸渗铝处理后试样表层形成一层致密的Al2O3层,有效地阻止了腐蚀性介质Cl-离子和基体活性铁的接触;热浸渗铝后X70管线钢渗铝层组织有多种析出物,其表层黑色物质为FeAl,有效地抑制了表面点蚀的发生;未处理试样表面含铁量高,产生活性铁原子,是盐雾腐蚀发生点蚀主要因素。     

Cr-Si-Al复合涂层的结构与耐蚀耐热性研究

应用Ｐ－Ｃ法对中碳钢进行Ｃｒ－Ｓｉ－Ａｌ复合涂覆,用光学显微镜观察了涂层的形貌。用电子 探针及扫描电镜测定了涂层的表面成分及Ｃｒ,Ｓｉ,Ａｌ在涂层中的分布,用Ｘ射线衍射测定了涂层的结构。将经涂覆后的试样进行盐水腐蚀和高温氧化试验,结果表明,其耐蚀和抗氧化性大幅度提高。     

Effect of Salt Spray Corrosion on Tribological Properties of HVOF Sprayed NiCr-Cr_3C_2 Coating with Intermediate Layer

The objective of the present work was to determine the influence of the neutral salt spray corrosion on the wear resistance of HVOF sprayed NiCr-Cr_3C_2 coating with intermediate layer. Ni-Zn-Al_2O_3 coatings as interlayers were prepared by low pressure cold spray(LPCS) between NiCr-Cr_3C_2 cermet coatings to form a sandwich structure to enhance the corrosion resistance properties. The tribological properties were examined using the UMT-3 fricition and wear tester by line-contact reciprocating sliding under dry and salt spray one week corrosion. The morphology, element distribution, and phase compositions of the coating and worn sufaces were analyzed by using scanning electron microscopy, energy dispersive spectrometry, and X-ray diffraction respectively. The corrosion behavior of the coating was studied by the open-circuit potential, the electrochemical impedance spectroscopy, potentiodynamic polarization, and salt spray corrosion methods. It is found that the sandwich structured coating has better corrosion resistance than the single layer coating. The results show that under dry wear conditions, the wear mechanism is abrasive and adhesive wear, whereas under salt spray corrosion conditions it becomes corrosion wear. The friction coefficient of the sandwich structured coating after salt spray corrosion is slightly lower than the dry friction coefficient, but the weight of the wear loss is lower than that under dry condition.