纳米Al2O3添加剂对VW75稀土镁合金微弧氧化膜层的影响

为提高VW75稀土镁合金表面耐蚀性,采用手动恒压法对合金进行了微弧氧化(MAO).基础电解液为硅酸盐碱性电解液(Na2SiO3-NaOH),通过添加纳米氧化铝(α-Al2O3)对电解液进行改性,优化原始微弧氧化层.利用数字式涂层测厚仪和带能谱的扫描电子显微镜(SEM)表征膜层厚度及表面微观组织特征,同时测试了合金在3....     

铝合金表面多功能膜的TiO_2溶胶封孔工艺及性能

对铝合金板进行阳极氧化与电解着色沉银处理,得到铝合金表面氧化膜涂层,然后用酞酸丁酯为主要原料制备的TiO2溶胶进行封孔处理制备多功能涂层。采用正交试验法,以涂层的耐蚀性和透明性作为评价标准来确定最佳封孔工艺。采用XRD、SEM、EDS对最佳工艺条件下封孔后的涂层结构、形貌及成分分布等进行表征,并对其耐蚀、耐擦拭性能、亲水性、光催化性及抗菌性等进行研究。结果表明:最佳封孔工艺为:按照V(酞酸丁酯):V(乙醇):V(醋酸):V(95乙醇)=10:40:8:30的原料配比制备TiO2溶胶,氧化膜在90℃溶胶中浸泡30 min烘干。TiO2封孔涂层为非晶体结构,主要分布在氧化膜表面,将着色的银纳米粒子封闭在孔底;经溶胶封孔后的氧化膜比基体具有更好的耐蚀性、抗菌性、自洁性与亲水性等特殊性能。     

催化剂载体FeCrAlY材料表面γ-Al2O3活性层的制备

本文介绍了用溶胶—凝胶法制备机动车尾气净化催化剂金属载体 Fe Cr Al Y材料表面γ- Al2 O3 活性层的工艺 ,根据热冲击循环中涂层重量变化讨论了在涂覆溶胶中加入无机类添加剂 ST及涂覆次数对涂层结合力的影响 ,用扫描电子显微镜 (SEM)观察了涂层的表面形貌并分析了涂层脱落情况。     

镁合金微弧氧化研究

在两种体系中研究了镁合金的微弧氧化.对比实验表明,磷酸盐体系中钕对氧化膜外观、厚度和耐蚀性有较大改善,提高钕盐浓度效果更佳;硅酸盐体系中,用稀土盐溶液浸泡试样后,制得的试样表面颜色较白,膜层分布更均匀,起弧容易.两种体系中用稀土转化膜取代镁合金表面的自然氧化膜进行微弧氧化处理,获得的陶瓷层分布更加均匀,表面更光滑致密,耐蚀性显著加强.     

用无机盐制备非载体Al2O3薄膜的溶胶—凝胶法研究

结晶三氯化铝经溶解，水解，胶溶制备了Ｂｏｅｈｍｉｔｅ溶胶，然后在石英玻璃上制备出表面光滑，平整，颗粒大小均匀的γ－ＡｌＯ３薄膜。ＤＴＡ分析表明，Ｂｏｅｈｍｉｔｅ凝胶膜２５８．７℃开始失水而转化为γ－Ａｌ２Ｏ３薄膜。     

镁合金表面微弧氧化处理研究进展

介绍了镁合金微弧氧化技术的发展,氧化膜形成的基本原理和生长规律,总结和分析了不同工艺参数如电压、电流密度、电解液体系等对氧化膜性能的影响规律,并简单介绍了电解槽中电导率、添加剂对氧化膜的影响情况,同时指出镁合金微弧氧化研究的不足及发展方向。     

Al2O3-Y2O3 Nano- and Micro-Composite Coatings on Fe-9Cr-Mo Alloy

Al2O3-Y2O3 nano- and micro-composite coatings were deposited on Fe-9Cr-Mo substrates by using sol-gel composite coating technology. The processing includes dipping samples in a sol-gel solution dispersed with fine ceramic powders, which are prepared by high-energy ball milling. High-resolution microscopy （FE-SEM） analyses show that the coating is composed of composite particle clusters with an average diameter of 1μm, and the coating is relatively dense without cracking during drying and sintering stages. XRD analyses show that the oxide coating is mainly composed of α-Al2O3 and γ-Al2O3. The oxidation tests performed at 600℃ in air show that the coatings are provided with much improved resistance against high temperature oxidation and scale spallation. It is indicated that nano-structured composite particles and reactive elements are integrated into the coatings, which plays an important role in preventing agglomeration of nano-particles and initiation of cracks.     

ZM5镁合金超音速微粒沉积Al-Si涂层的耐腐蚀性能

为提高镁合金的耐蚀性能,采用超音速微粒沉积技术在ZM5基体上制备Al-Si防护涂层。采用环氧面漆对涂层进行封孔处理,采用电化学方法和中性盐雾实验对镁合金基体、涂层及涂层封孔后的抗腐蚀性能进行测试。结果表明:防护涂层致密,缺陷少,可显著提高ZM5镁合金的耐蚀性能;腐蚀电流密度比基体降低2~3个数量级,阻抗模值提高2个数量级,而涂层封孔后耐蚀性能进一步提高。相比镁合金24 h严重腐蚀,涂层中性盐雾实验1 000 h仅轻微腐蚀,腐蚀造成的质量损耗较小,封孔后涂层未见明显腐蚀,可为镁合金提供长效防护。     

溶胶-凝胶法制备超细氧化钐的工艺研究

以柠檬酸为络合剂,用溶胶-凝胶法制备超细Sm2O3粉,并用TG/DTA对产物进行了热分析,用XRD,SEM对产物的粒度及分散性进行了表征;考察了反应温度及溶液的pH值对产物粒度、形貌及分散性的影响.结果表明,柠檬酸溶胶-凝胶法制备Sm2O3的最佳反应温度为80℃,当溶液的pH值为7时,产物的粒度和分散性最佳,XRD测出原始晶粒的精确尺寸为21.5nm,SEM所测二次颗粒的平均粒径为100nm左右.     

溶胶-凝胶法合成Y2O3-SiO2:Eu3+,Bi3+发光体及发光特性研究

采用溶胶-凝胶法低温合成了Y2O3-SiO2:E u3+,Bi3+发光体,研究了烧结温度、Eu3+及Bi3+浓度、Y 2O3与SiO2的配比对发光强度的影响.通过X射线粉末衍射、热重及差热分析,研究了由凝胶至发光晶体的转变,通过激发光谱和发光光谱的测试,讨论了材料的发光特性及Bi 3+对Eu3+的敏化作用.     

正脉冲电压对Mg-4Gd-3Y-0.5Zr合金微弧氧化膜组织形貌与耐蚀性能的影响

采用SEM、覆层测厚仪、电化学工作站等研究了正脉冲电压对Mg-4Gd-3Y-0.5Zr稀土镁合金双脉冲微弧氧化膜的组织形貌及耐蚀性能的影响。结果表明：随正脉冲电压的升高,膜层厚度增加,膜层表面微孔数量减少、孔径增大,烧结强度增加,裂纹增大;耐蚀性能先增强后降低,均显著优于合金基体;最佳正脉冲电压为450 V,腐蚀电位与腐蚀电流分别为-1.495 V、10-8.62 A/cm2。     

Structure and Corrosion Resistance of Microarc Oxidation Coatings on AZ91D Magnesium Alloy

Magnesium alloys are widely used as shells of 3C (computer, mobile phone and consumer electronics) equipments for its impressive mechanical and physical properties, such as low density, good resistance to electromagnetic radiation, suitable for high pressure diecasting and easily recycling, etc. But poor corrosion resistance confines its extensively application. In this paper, protective coatings was successfully prepared on AZ91D magnesium alloys by micro-arc oxidation (MAO) and painting process. Microstructures and phases of MAO coatings were invesgated with scanning electron microscope (SEM) and X-Ray diffractometer. Mechanical properties of MAO coating, such as adhesive force and corrosion resistance, were also tested. Results showed that MAO coatings were a good base for painting process. MAO coatings with paint have good adhesive properties to base metal and excellent corrosion resistance. Micro-arc oxidation with painting process is a good kind of surface treatment to improve the corrosion resistance of mobile phone shell made of AZ91D magnesium alloys.     

Preparation and Corrosion Resistance of Rare Earth Ceramic Film on AZ91 Magnesium Alloy

With the purpose of improving corrosion resistance and solving environmental pollution caused by traditional protective technique, rare earth ceramic film on AZ91 magnesium alloy was prepared by dip coating process, and technical parameters of preparation were defmed. Microstructure and composition of the film were studied and corrosion resistance was evaluated as well. The results show that rare earth ceramic film is uniform,dense, with strong cohesion and intact coverage. The film is mainly made up of CeO2 and MgCeO3. The results of corrosion experiments approve that the film acts as a barrier to isolate the contact of the substrate with corrosion media and decreas corrosion rate. Polarization curve of the coated sample shiftes to positive potential obvito 2.7 × 104 Ω. These facts indicate that rare earth ceramic film could effectively improve corrosion resistance of AZ91 magnesium alloy.     

热喷涂与微弧氧化法制备镁合金表面陶瓷层

通过对热喷涂与微弧氧化这两种镁合金表面陶瓷层制备方法的综合比较,探讨了它们各自的适用范围、优缺点和应用前景,并对它们作为镁合金表面防护技术的发展方向进行了展望。     

Preparation and Corrosion Resistance of Rare Earth Conversion Coatings on AZ91 Magnesium Alloy

Magnesiumalloysarewidelyusedinweaponin dustry,spacenavigationandhavegoodpotentialof applicationanddevelopmentindailycommunication facilitiesduetotheirpropertiesoflightweightandhighstrength[1].Appliedasstructuralmaterials,mag nesiumalloysmayeasilycrackduet…     

报废镁合金表面涂层的清洗技术研究

以苯甲醛为主溶剂,甲酸为助溶剂,液体石蜡为抑制挥发剂的有机溶液去除报废镁合金表面涂层,并对去除机理进行研究。结果表明,当苯甲醛和甲酸的体积比为13∶7,处理时间为10min时,涂层的起皱率可达100%;在涂层去除过程中,有机溶剂分子与涂层聚合物之间没有发生化学反应,溶剂对涂层聚合物无降解破坏作用,而是使聚合物空间网状结构扩大,减弱了有机涂层与基材间的作用力,促使涂层与镁合金基材分离。     

镁合金电镀铝前处理工艺的探讨

采用氢氟酸对AZ31镁合金电镀铝进行前处理,并对钝化处理得到的转化膜的物相、表面形貌和耐蚀性进行测定.结果表明,钝化处理得到的转化膜对镁合金基体有较好的保护作用,符合镀前处理的要求.     

Preparation and Performance of Rare Earths Chemical Conversion Film on Magnesium Alloy

Golden yellow cerium conversion film was obtained on magnesium alloys surface by immersion method and the preparation parameters were established. The influence of different process parameters on the surface morphology and performance of the conversion film were analyzed by means of SEM and electrochemical method. Formation dynamics about cerium conversion film on magnesium alloy in solution containing cerium salt and the anti-corrosion behavior of the conversion film in 3.5% NaCl solution were studied by electrochemical method respectively. The results shows that the conversion film is more compact at room temperature when concentration of cerium sulfate is 10 g·L-1 in the solution; the open circuit potential of the magnesium sample moves up to positive direction about 100 mV, the surface of conversion film becomes even and lustrous, and the adhesion intensity of conversion film increases when adding aluminum nitrate into the solution containing cerium salt. The pH value of the solution and immersion time of the sample in the solution also affect the surface morphology and anti-corrosion property of the conversion film. After covered by rare earths conversion film, the anti-corrosion property of magnesium alloy is obviously improved. Rare earth conversion film has self-repairing capability in corrosion medium.     

钛合金表面微弧氧化耐磨和耐蚀膜层的研究进展

微弧氧化是一种直接在有色金属或其合金表面原位生成陶瓷膜的新技术,利用该技术可在钛合金表面生成耐磨和耐蚀性能优良的膜层。介绍了微弧氧化技术及其特点、钛合金表面微弧氧化耐磨和耐蚀膜层的研究进展,并指出了钛合金表面微弧氧化耐磨和耐蚀膜层的应用前景和今后膜层研究的发展方向。