含氟两亲性聚合物刷构筑及防污应用研究进展

表面接枝聚合物刷是一种改善表面理化性质,防止蛋白质等生物大分子和其他污损生物吸附的有效方法。含氟聚合物由于其强疏水性、低表面能和低表面粘附力等特点,是构建两亲性聚合物刷的理想组分之一。本文概述了含氟两亲性聚合物刷的构筑方法、种类和防污机理,着重介绍了该类涂层在抗蛋白、抗菌、藻类以及其他污损生物吸附方面的最新研究成果,详细分析了含氟两亲性聚合物刷化学组成、表面重构和弹性模量等因素对微相分离行为以及防污性能的影响规律。亲疏水组分比例会对涂层的相分离行为产生影响,改变亲疏水组分比例可以形成不同尺度、不同形貌的相分离结构,进而影响涂层的防污性能。亲疏水组分的连接方式会影响涂层表面的重构行为,实现涂层亲疏水性能的转变,进而实现调控涂层表面的防污行为。从分子设计层面初步揭示了含氟两亲性聚合物刷的防污机理。最后指出构筑新型的多种防污机制协同作用的多功能化含氟两亲性聚合物刷,是未来两亲性聚合物涂层的主要发展方向。     

热障涂层的研究现状与发展趋势

热障涂层是一类高温防护涂层,由于其应用的广泛性,已成为近年来涂层研究领域的热点之一。对热障涂层国内外的研究进展进行了综述,重点阐述热障涂层成分的选择、热障涂层的结构设计、热障涂层的制备工艺、热障涂层的失效机理、寿命预测以及热障涂层的发展趋势。     

常温钢铁磷化处理的研究

用正交试验法优选了磷化配方,通过金相显微镜观察优化后的磷化膜,其金相结构致密、连续.电化学方法测试成膜过程,其极化曲线表明,磷化成膜后,腐蚀电流基本保持不变.利用X射线光电子能谱(XPS)测定膜表面的元素组成,由Zn、Fe、P的不同峰值的能谱、O的能谱峰及俄歇能谱同时存在,可说明磷化膜主要是由Fe及Zn的多种磷酸盐构成.同时,技术性能测试表明,该磷化液溶液稳定、沉渣少、成膜速度快且磷化膜耐蚀性能好.     

孔表面化学镀Ni-P及其沉积机制

用扫描电镜(SEM)对化学镀Ni-P沉积层形貌进行观察,用能谱仪(EDS)对镀层成分进行分析,用增重法测量沉积速率.试验结果表明,化学镀初期镀层表面形貌为等轴颗粒状,形成连续膜后镀层形貌为胞状.胞状组织上形成的晶核成分与基体胞状组织成分不同.通孔和盲孔高度分别小于1.76 mm和2.2mm时,化学镀Ni-P沉积速率随孔...     

聚醚改性多面体低聚倍半硅氧烷构筑耐水性亲水防雾涂层

目的制备一种高耐水性的亲水防雾涂层。方法通过光引发巯基-烯点击化学反应,合成聚醚改性多面体低聚倍半硅氧烷(POSS),得到聚醚改性POSS(POSS-SH6-PEGMA2),采用FT-IR、1H-NMR表征合成产物的结构。将其与亲水性UV树脂混合,在聚碳酸酯基板上涂布、光固化,形成高耐水性亲水防雾层。采用X射线光电子能谱仪(XPS)分析涂层表面元素,通过超景深三维显微镜对涂层表面形貌进行分析,使用接触角分析仪表征涂层的亲水性,并评价涂层的耐水性和防雾性能。结果通过XPS得到的结果表明,POSS在涂层中发生迁移,富集在涂层表面。通过超景深三维显微镜观察涂层表面发现,表面产生了一系列不同的微观结构,表面粗糙度增大。随涂层中POSS-SH6-PEGMA2的含量增大,涂层的耐水性、亲水性以及防雾性能增强。当POSS-SH6-PEGMA2的含量为55%时(POSS含量为9.71%),涂层的耐水性(吸水率为7.3%)、亲水性(水接触角为7.41°±2.35°)和防雾性能最佳。结论在聚乙二醇二丙烯酸酯涂层中添加一定量聚醚改性POSS(POSS-SH6-PEGMA2的含量为55%),能获得高耐水性的亲水防雾涂层。     

Formation mechanism of amorphous Ni-Fe-P alloys by electrodeposition

The formation mechanism of the amorphous Ni-Fe-P coating was studied by analysis of the forming thermodynamics, dynamics, and crystallography of the amorphous alloy. The results show that, in the initial stage of deposition a thin “crystal epitaxial growth” layer first forms, and then transforms to amorphous gradually. The cross section in Ni-Fe-P coatings by electrolytic etching exhibits a banded structure of alternate dark and light bands. It is proposed that the banded structure is caused by a change in the P content with thickness,which is due to alternated depletion and enrichment of [OH^-] in the diffusion layer resulting from the generation and evolution of hydrogen gas. The amorphous Ni-Fe-P coating will be formed in proper composition, high nucleation rate and strongly hindered growth of the crystal nucleus. Amorphous Ni-Fe-P alloys form as islands, and grow up by layer.     

燃气轮机热障涂层的研究现状与发展趋势

综述了热障涂层的原理、作用、组成和制备方法、失效模式等方面的研究现状,在此基础上探讨了热障涂层的发展趋势.     

扫描速度对激光熔覆Ni基WC合金涂层组织与性能的影响

在45钢表面激光熔覆镍基WC合金涂层,分析扫描速度对熔覆层的成型、组织和性能的影响。采用金相显微镜、扫描电镜、显微硬度仪和摩擦磨损试验机对熔覆层的显微组织、化学成分、相组成以及耐磨耐蚀性进行分析测试。结果表明,熔覆层组织致密,与基体有良好的冶金结合。扫描速度增大,熔覆层出现裂纹的倾向增大,底部柱状晶外延生长层宽度减小,组织晶粒细化,相组成种类几乎没有变化,显微硬度增大,耐磨耐蚀性提高。当扫描速度为200 mm/min时得到成型性及耐磨耐蚀性优良的熔覆层。     

Chemical conversion coating on AZ31B magnesium alloy and its corrosion tendency

The morphology change of the magnesium matrix after pre-treatment and the mor-phology as well as the phase composition of chemical conversion coating formed by phosphate were studied using scanning electron microscope and X-ray diffraction. The corrosion resistance of the coating was studied by salt spray and damp test, and the corrosion tendency during salt immersion test was analyzed. The results show that the phase composition before and after pre-treatment is almost change- less, and the deep microflaw appears between α and β phases during acidic pickling. The phosphate conversion coating is mainly composed of Mg, MgO, and some amor-phous phase, and it can provide a good protection for the AZ31B alloy. Results from corrosive morphology indicate that the growth and the corrosion resistance of the phosphate conversion coating are related to the forming process of the AZ31B matrix.     

Dynamic residual stress in thermal sprayed coatings

0IntroductionExtensive studies and measuring methods for residualstress in thermal sprayed coatings had been conducted bymany researchers,such as X-ray diffraction,neutron dif-fraction,layer removal and also Almen test[1-4].Howev-er,up to date,none has in…     

基于快速原形的陶瓷型喷涂法造型工艺研究

快速原型制造技术与陶瓷型精密铸造相结合是目前金属模具快速制造的有效方法。为了进一步缩短制造周期，降低生产成本，摸索出一套新的陶瓷型精密铸造工艺－喷涂法陶瓷型造型，对该工艺的涂料配方，喷涂工艺进行研究，并经试验验证。     

热镀锌无铬自润滑涂层及性能试验研究

目的 改善热镀锌板成形条件,减少冲压成形工序.方法 研发了一种热镀锌自润滑板,采用扫描电镜研究了热镀锌自润滑涂层的微观结构及成分,采用X射线荧光光谱仪测量了膜重.通过中性盐雾试验、摩擦系数测定、烘烤前后色差变化、涂敷凡士林后色差变化等方法,研究了涂层膜厚对耐蚀性、自润滑性、耐热性、耐指纹性、耐水性的影响,并得出最佳性能的膜层厚度控制范围.结果 自润滑膜层为一种有机-无机混合的致密环保涂层,其在NSST/72 h条件下锈蚀面积小于5％,摩擦系数小于0.10,涂敷凡士林后色差变化值小于1,具有良好的自润滑性、耐蚀性、耐指纹性、耐水性等性能,满足用户的冲压成形条件.结论 自润滑涂层的耐蚀性、耐热性、耐指纹性、耐水性等性能均已达到,甚至超越了现有无铬钝化的水平.涂层自润滑性、耐蚀性、耐指纹性随膜厚的增加而增强,耐热性随膜厚的增大而变差,膜厚对耐水性无明显影响.控制涂层膜厚为0.9～1.6g/m2,可确保涂层具有更加优良的稳定的自润滑性、耐蚀性和耐热性.     

Forming limits of nickel coating on right region

The forming limits of nickel coating on the right region were studied, so as to direct the preparation of the material and help the production of workpieces. The electrodeposited nickel coating was prepared on steel substrate to form advanced structures, and its plastic instability was investigated by the Swift Plastic Instability Theory. By using the compound law for laminated sheet metals, explicit equations for the calculation of the instable eigen values were deduced. The forming limit diagrams of the nickel coating on the right region were plotted. It is exhibited that the forming limit of the coating sheet is between the forming limits of the individual nickel coating and steel substrate. The forming limit of the nickel coating is not so good as that of the steel substrate, and the forming limit strain of the coating sheet tends to diminish with the increase of thickness of the coating. The greater the normal anisotropic coefficient of the materials is, the better the forming limit is.     

丙烯酰胺浓度对聚二甲基硅氧烷表面涂层性能的影响

硅橡胶的疏水特性致使其在体内的减阻性能较差,亟须开展其表面亲水性能和润滑性能均良好的工艺研究。以聚二甲基硅氧烷（PDMS）为基材,以丙烯酰胺（AAm）为反应单体,通过紫外光固化工艺在PDMS表面制备5种不同浓度的聚丙烯酰胺（PAAm）涂层,对涂层的表面成分、表面粗糙度、厚度、亲水性能及润滑性能进行表征,讨论AAm浓度对涂层性能的影响。结果表明：AAm浓度对涂层厚度和粗糙度有显著影响,即随着AAm浓度的提升,涂层厚度和粗糙度均呈上升趋势;AAm浓度也改善涂层的亲水性能和润滑性能,即与基材PDMS(110°)相比,含20 wt.%AAm的涂层接触角低至18.24°,降低到基材的16.6%;含8 wt.%AAm的涂层摩擦因数低至0.039,与基材PDMS相比降低98.2%。提出一种硅橡胶表面构建牢固涂层的简单且高效的方法,可为软材料表面改性提供较好的借鉴。     

CuCo2Be表面等离子喷涂制备Cr3C2-NiCr/NiAl复合涂层成形机理及界面扩散研究

选用等离子喷涂技术在CuCo2Be合金表面制备Cr3C2-NiCr/NiAl复合涂层。选用DTA、XRD、SEM、EDS等分析手段探讨Cr3C2-NiCr/NiAl复合涂层的形成机理及其组成涂层的化合物、物相的形成特点及规律。结果表明:DTA分析发现镍铝打底层在热喷涂过程中由于系放热反应,可能生成Ni2Al3、NiAl3、NiAl等物相;SEM、EDS分析发现复合涂层组织呈现明显的层状,在镍铝打底层中镍铝化合物为角状;XRD分析发现涂层物相在成形的不同阶段和时间内其生成的化合物类型、数量都呈现不同的变化。利用XRD、EDS分析界面处各相的生成及元素的分布、扩散情况,表明在界面处存在一定的元素扩散,界面为微冶金结合。     

离心铸造复合轧辊裂纹原因分析

裂纹是离心铸造高镍铬复合轧辊报废的主要原因之一.针对高镍铬轧辊辊身出现的裂纹问题,分析其形成原因主要为冷型转速过高,化学成分和涂料也是造成轧辊裂纹的重要影响因素.     

Oxidation-Resistant Aluminide Coatings on γ-TiAl

The long-term application of TiAl alloys based on the -phase at temperatures above 750–800°C requires suitable surface coatings to provide the needed oxidation resistance. Without a coating, these alloys, containing large amounts of titanium, suffer from rapid oxidation attack at elevated temperatures. The pack-cementation coating process was used to aluminize the surface region of a Ti–50 at.% Al alloy to TiAl₃, the most promising, oxidation-resistant phase in the Ti–Al system. The isothermal oxidation behavior of the coated alloy was studied in the temperature range 800–1000°C in air for up to 300 hr. The aluminide coating greatly improves the oxidation resistance of -TiAl, forming a protective alumina scale. The rapid aluminum interdiffusion between the TiAl₃ coating and the -TiAl substrate determined the effective life of the coating. In addition, the oxidation behavior of the TiAl₂ phase formed by interdiffusion of the coating system was studied by oxidation of cross sections.     

内燃机排气阀的损坏机理与“PSR——1”号涂层合金的应用

作者用金相,扫描电子显微镜,X光衍射和电子探针分析技术对国产燃油与典型工况内燃机排气阀所用钢材21—4N与4Cr10Si2Mo的损坏机理进行了研究。着重检验了表面腐蚀保护膜的形貌,组成及其在反复应力作用下的破坏过程。无论汽油机或柴油机气阀,都是在燃气腐蚀与疲劳应力的联合作用下过早地产生所谓“麻坑”而损坏。试验已经充分证明:气阀上采用一种表面处理方法所得到的涂层可以有效地减少并推迟“麻坑”的产生,数倍地提高了使用寿命。本文研究了一种叫做PSR—1号的涂层合金及涂层工艺,在VF—79型气阀涂层专用设备上制备的涂层气阀具有很高的耐磨耐腐蚀性能,其全面技术经济指标均已超过传统堆焊阀。经陆路,内河与海洋广泛行驶考核证明,这种涂层无论对汽油机或柴油机排气阀均有极好的保护能力,目前已通过鉴定并正式投产使用。     

A technique for fabrication of coated TiCN-based cermets with functionally graded structure

A technique for fabrication of coated TiCN–Ni–Mo cermets with functionally graded microstructure and composition has been developed. A multilayer coating and the substrate near-surface zone with graded microstructure form as a result of interaction between the cermets and chromium vapour in vacuum. The coating consists of an upper layer of chromium carbide of about 10 μm in thickness and a thin interlayer of less than 1 μm composed of a Ni–Cr alloy between the carbide layer and the substrate. The wide near-surface zone of over 100 μm in thickness with graded microstructure and composition forming under the coatings has an increased Cr content in the Ni-based binder. This zone is characterised by enhanced corrosion- and oxidation-resistance.     

氮碳共渗对Ni-W-SiC复合镀层的组织及性能的影响

讨论了Ni-W-SiC复合镀层与氮碳共渗复合强化的组织结构及性能，结果表明，氮碳共渗后复合镀层的硬度和耐磨性远高于未氮碳共渗的复合镀层，扫描电镜结果表明，在共渗处理中，复合镀层存在硬度梯度，且基体中的换向复合镀层扩散，形成“钉扎效应”，显著提高了镀层与基体的结合力。X射线衍射表明，复合镀层经氮碳共渗后，产生很多新相，这些相的存在显著提高了复合镀层的硬度和耐磨性。