等离子喷涂Al2O3+TiO2复合陶瓷涂层的组织结构

利用ＳＥＭ,ＴＥＭ,ＥＤＡＸ及Ｘ射线等手段研究了Ａｌ２Ｏ３＋ＴｉＯ２／ＮｉＣｒＡｌＹ复合陶瓷等离子喷涂层的组织结构,涂层呈片层状,Ａｌ２Ｏ３＋ＴｉＯ２陶瓷涂层由γ－Ａｌ２Ｏ３,ＴｉＯ２及少量的α－Ａｌ２Ｏ３组成,由于喷涂层温度比较高,部分熔化的Ａｌ２Ｏ３和大部分熔化的ＴｉＯ２发生了一定程度的互熔,形成了Ａｌ２Ｏ３＋ＴｉＯ２共晶组织。片层内由Ｎｉ基固溶体及弥散分布其上的γ相（Ｎｉ３Ａｌ）组成,片间为     

硬质合金粉末表面涂层陶瓷的材料

利用溶胶－凝胶法在ＴｉＣ粉末,（Ｗ,Ｔｉ）粉末表面涂层Ａｌ２Ｏ３陶瓷,通过热压烧结制得了两种新型涂层的刀具材料（ＦＴＣ１和ＦＴＣ２）,粉末涂层材料ＦＴＣ１和ＦＴＣ２的力学性能满足刀具材料的使用要求。利用扫描电镜观察发现基体粉末表面较均匀地涂覆了一层α－Ａｌ２Ｏ３陶瓷,并对材料的力学性能和微观结构进行了分析。     

激光熔覆Al2O3+TiO2复合陶瓷涂层的微观结构

研究了４５＃钢表面Ａｌ２Ｏ３＋ＴｉＯ２复合陶瓷激光熔覆层的微观组织和相结构、Ａｌ２Ｏ３＋ＴｉＯ２复合陶瓷激光熔覆涂层由α－Ａｌ２Ｏ３,ＴｉＯ２,γ－ＴｉＯ２,γ－Ａｌ２Ｏ３及Ａｌ２ＴｉＯ５相组成,消除了等离子喷涂层的层状组织特征,形成了大致方向的柱状晶,晶内为溶入了Ｔｉ及少量底层元素的α－Ａｌ２Ｏ３;晶界为由ＴｉＯ２和Ａｌ２Ｏ３形成的Ａｌ２ＴｉＯ５相,溶有少量的Ｃｒ,Ｆｅ,Ｙ取代了Ａｌ２ＴｉＯ５     

Na2O—Al2O3—B2O3—SiO2系统溶胶,凝胶涂层的振动光谱研究

本文用振动光谱分析了Ｎａ２Ｏ－Ａｌ２Ｏ３－Ｂ２Ｏ３－ＳｉＯ２系统溶胶中的化学反应和用浸渍法制备的凝胶涂层结构。结果表明：部分硼、铝在溶胶陈化初期就与Ｓｉ（ＯＣ２Ｈ５）４的水解或缩聚产物反应形成线性聚合物，宜于浸涂。热处理时涂层中继续形成Ｓｉ－Ｏ－Ｓｉ、Ｓｉ－Ｏ－Ａｌ和Ｓｉ－Ｏ－Ｂ键；基本结构单元为［ＳｉＯ４］、［ＢＯ４］、［ＢＯ３］和［ＡｌＯ４］。     

原位生成TiB2颗粒增韧SiC基复相陶瓷研究

提出一种新的方法制备ＳｉＣ－ＴｉＢ２颗粒复相陶瓷。通过Ｔｉ，Ｓｉ与Ｂ４Ｃ之间的化学反应在ＳｉＣ基体中原位生成ＴｉＢ２颗粒，获得的ＴｉＢ２颗粒一般在５μｍ以下，但发现有ＴｉＢ２颗粒团聚现象。其中ＳｉＣ－ＴｉＢ２３０％（ｖｏｌ）复相陶瓷的断裂韧性和三点弯曲强度分别比ＳｉＣ基体提高约１倍，达到４．５ＭＰａ·ｍ＾１／２和４００ＭＰａ。认为ＴｉＢ２颗粒与ＳｉＣ基体之间热膨胀系数不同导致的残余应力场引起的裂纹     

钌钛锡氧化物阳极表面形态及电化学性能研究

通过对Ｒｕ，Ｔｉ，Ｓｎ氧化物涂层电极中ＳｎＯ２含量的研究，确定了Ｒｕ０．２－Ｔｉ０．８－ｘＳｎｘＯ２电极涂层中ＳｎＯ２含量与电极形貌，电化学活化面积之间的关系，最终确定Ｒｕ０．２Ｔｉ０．７Ｓｎ０．１Ｏ２涂层具有最大的电化学活性表面积。     

釉面砖表面掺铅TiO2涂层的溶胶——凝胶法制备及其光催化性能

用溶胶－凝胶法在釉面砖上制备了均匀的ＴｉＯ２及掺铅ＴｉＯ２涂层，讨论了影响涂层质量的某些因素，用Ｘ射线光电子能谱仪（ＸＰＳ）研究了釉面涂层的化学组成。在紫外线及日光照射下，ＴｉＯ２涂层奥面砖可以对有机磷农药光催化降解。掺铅ＴｉＯ２涂层釉面砖的光催化降解率明显高于未掺铅的ＴｉＯ２涂层釉面砖的光催化降解率。该类材料可望在环境保护、污水处理等方面有广阔的应用前景。     

金属陶瓷涂层耐蚀性影响因素的研究

研究了溶胶制备中所用催化剂种类、基体金属前处理及涂层厚度对金属陶瓷涂层耐蚀性的影响,不含ＣＩ＾－催化剂的溶胶－凝胶配方所得陶瓷涂层的耐蚀性最了,适当的前处理及适宜的涂层厚度有利于提高陶瓷涂层的耐蚀性。     

长寿命金属阳极涂层的研究及应用

总结了Ｒｕ－Ｔｉ－Ｓｎ三组份金属阳极涂层在氯酸盐电解生产的经验，据资料报导与ＲｕＯ２相比，涂层上的ＩｒＯ２不会在阳极电位转化成可溶性化合物，Ｉｒ原子对氧原子的吸附是可逆的，说明Ｉｒ比Ｒｕ具有抗腐蚀、耐钝化，在原涂层中加Ｉｒ，可使其寿命延长至原来的３倍。     

铝镁浇注钢包衬渣线部位Al2O3—ZrO2—SiO2系陶瓷保护涂层的研究

以铝镁浇注料钢包衬为母体，主要研究渣线部位预防性Ａｌ２Ｏ３－ＺｒＯ２－ＳｉＯ２系陶瓷保护涂层作用机理，以期钢包各部位寿命同步，进面提高其寿命节材降耗。     

3种溶液体系中镁合金微弧氧化研究第一部分——氧化膜的相组成及其耐蚀性

利用直流脉冲方法在3种溶液体系中于AZ91D镁合金表面制得了微弧氧化陶瓷膜,分析了各膜层的厚度、显微硬度、相组成和耐蚀性能。结果表明,不同体系中的膜层增厚速率不同,形成膜层的相关成分也不同。通过比较微弧氧化前后镁合金的动电位极化曲线和交流阻抗发现,处理后的AZ91D镁合金的耐蚀性得到了明显改善。     

Novel anti-corrosion silicon dioxide coating prepared by sol–gel method for AZ91D magnesium alloy

Silicon dioxide sols which can be directly applied on the surface of AZ91D magnesium alloy to improve its corrosion resistance were prepared by two-step process. In this study, tetraethyl orthosilicate (TEOS) and triethoxyvinylsilane (VTEO) were employed as the precursors to prepare SiO₂ (TV) sol, as a comparison, the other SiO₂ (T) sol prepared by only tetraethyl orthosilicate (TEOS) as precursor was also investigated. Fourier transform infrared (FT-IR) spectrum was performed to analyze the structure differences between the SiO₂ (TV) sol and SiO₂ (T) sol. The surface morphology of the silicon dioxide coatings was characterized by scanning electron microscope (SEM). The results show that more uniform and denser coatings can be obtained from SiO₂ (TV) sol. The corrosion resistance of the AZ91D magnesium alloy coated by silicon dioxide coatings was examined by electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization tests in 3.5 wt.% NaCl aqueous solution. The results indicate that the corrosion resistance of the AZ91D substrate is greatly improved by the SiO₂ (TV) sol coatings.     

Effect of pore content and pH on the corrosion behavior of hydrophobic ceramic coatings

In this paper, superhydrophobic ceramic coatings were successfully prepared on stainless steel substrates (S304) by sol–gel method, and the effects of pore content and pH conditions on the corrosion resistance of hydrophobic ceramic coatings were studied. As the porosity increases, the contact angle of the coating increases. Among them, the contact angles of the coatings with 15% and 20% porosity in different pH solutions are all greater than 150°, achieving superhydrophobic surfaces. The contact angle results before and after corrosion show that the solution with a higher pH has a greater damage to the hydrophobicity of the coating. The corrosion resistance of the coatings was evaluated comparatively from polarization curves and electrochemical impedance spectroscopy. As the hydrophobicity improves, the corrosion resistance of the hydrophobic ceramic coating is enhanced. The impedance moduli at .01 Hz of the coating are 1.04 × 10³ times (pH 4), .13 × 10³ times (pH 7), and .74 × 10³ times (pH 10) of the bare steel, respectively. With the increase of pH, the corrosion resistance of hydrophobic ceramic coatings decreases, because OH⁻ in the corrosion solution is more easily adsorbed on the surface of the coating, thereby destroying the long hydrophobic chains.     

粘接剂对热化学反应陶瓷涂层结构与性能的影响

采用相同的陶瓷骨料(SiO2+Al)、添加剂(MgO+CrO3)和固化工艺,分别以磷酸铝和水玻璃为粘接剂,在Q235钢上制备陶瓷涂层,对其相成分、微观形貌、热震性能以及耐蚀性能进行了分析测试,讨论了粘接剂对涂层耐蚀性的影响。结果表明,尽管以磷酸铝为粘接剂的陶瓷涂层在固化过程中产生少量孔隙,但仍具有比以水玻璃为粘接剂的陶瓷涂层更优异的抗热震性能以及耐酸、碱、盐腐蚀性能。     

Effect of Ti amount on wear and corrosion properties of Ti-doped Al2O3 nanocomposite ceramic coated CP titanium implant material

Al₂O₃ and Ti-doped Al₂O₃ nanocomposite ceramic coatings were prepared by using a sol-gel dip-coating process. Corrosion and wear resistance of Al₂O₃ ceramic coatings in relation to Ti amount were carried out using pin-on-disk tribotester, potentiodynamic polarization and electrochemical impedance spectroscopy (EIS). Surface characterizations before and after the corrosion and wear tests were investigated by the scanning electron microscope (SEM) and X-ray diffraction (XRD) and hardness analysis. The results of corrosion and wear tests exhibited that the corrosion and wear resistance of nanocomposite ceramic coatings became better than uncoated samples. Also, corrosion and wear resistance of nanocomposite ceramic coatings improved with Ti doping content increased.     

Characterization and property of microarc oxidation coatings on open-cell aluminum foams

The ceramic coatings were prepared on open-cell aluminum foams by microarc oxidation (MAO) treatment in an alkaline-silicon electrolyte. The morphology, microstructure, elemental distribution, and phase composition of the MAO coatings were investigated by scanning electron microscopy, energy-dispersive X-ray spectroscopy, and X-ray diffraction, respectively. The corrosion behaviors of the coated and uncoated foams were evaluated by electrochemical polarization measurement. The results show that the MAO coatings cover the surface of open-cell aluminum foams. The coatings were composed of an external porous layer and an internal dense layer. The main phase of the MAO coating phase is γ-Al₂O₃. The coated aluminum foams exhibit more positive corrosion potential and lower corrosion current density compared with the uncoated aluminum foams.     

Environment Friendly Nano Silicon Dioxide Accelerated Zinc Phosphate Coating on Mild Steel Using a Series of Surfactants as Additives

Mild steel panels were subjected to zinc phosphate conversion coating accelerated by environment friendly nano silicon dioxide using a series of cationic surfactants as additives. Four cationic surfactants have been synthesized in the absence of solvent using triethylamine and four different long chain alkyl halides. From ¹H NMR and ¹³C NMR spectra the chemical structures of the synthesized surfactants were confirmed. The nano silicon dioxide accelerator provided a highly porous phosphate coating ensuring good adhesion to the consecutive top coating. The incorporation of cationic surfactants as additives led to fine-grained coatings which enhanced adherence and excellent corrosion resistance property to the phosphate coating. The performance of the surfactants as a corrosion inhibitor increases with the increase in the hydrophobicity of the side-chain length. Accelerator and additive incorporation effectively reduced the extent of zinc dissolution during phosphating and exhibited the highest polarization resistance. The good dispersability of additives and increased hydrophobicity yielded coatings with improved protection against corrosion. The corrosion inhibition performance of the coated steel has been studied by Open Circuit Potential (OCP), Potentiodynamic Polarization Curve, Electrochemical Impedance Spectroscopy (EIS) and salt spray test.     

Effect of sol–gel layers obtained from GLYMO/MTES mixtures on the delamination of a cataphoretic paint on AA1050

In this study, the performance of different sol–gel layers produced from different mixtures of silicon alkoxides precursors (γ-glycidoxypropyltrimethoxysilane, GLYMO, and methyltriethoxysilane, MTES) applied on AA1050 aluminum alloy as a pretreatment prior to depositing an electrophoretic paint (polyether–polyamine polymeric blend) is investigated. The structure of the sol–gel coatings was characterized by means of ATR FTIR, while the corrosion protection properties were assessed by polarization curves. Accelerated laboratory tests, such as exposure in both neutral and acetic salt spray chambers and filiform corrosion tests, were employed to investigate the corrosion protection properties of the cataphoretic paint-coated samples. The failure mechanisms of the different coatings were investigated. The experiments revealed that the presence of GLYMO in the sol–gel coating seems not to be suitable for acting as a coupling agent between the paint and the aluminum substrate. On a positive note, this work shows that the filiform corrosion test seems to be the most appropriate test to evaluate the efficiency of sol–gel layers employed as pretreatment to enhance the corrosion protection provided by a paint on an aluminum substrate.     

LY12铝合金钼酸盐转化膜及其耐蚀性

应用电化学方法研究了LY12铝合金钼酸盐转化膜的成膜过程及其在3.5%NaCl溶液中的耐蚀性。结果表明,钼酸盐转化处理成膜工艺简单,经钼酸盐转化处理的铝合金的耐蚀性能提高,转化处理提高了铝合金的抗点腐蚀能力。电位-时间曲线表明钼酸盐转化膜成膜较为顺利。分析了膜的形成机理及耐蚀机理。     

金属基耐高温陶瓷涂层抗热冲击性能的研究

为提高金属基陶瓷涂层的抗热冲击性能，以无机胶粘剂磷酸二氢铝、耐磨陶瓷骨料氧化铝、碳化硅和氧化镁混合后涂覆于金属表面制得陶瓷涂层。通过交替加热及冷却试验测试该陶瓷涂层的抗热冲击性能，并与其他人的研究数据进行比较。所得涂层抗热冲击次数超过10次，超过了其他人的实验数据，这是由于涂层与基体在界面处相互扩散形成过渡层。另外，宏观上的机械联锁有利于提高涂层与基体在界面处的结合，从而提高了其抗热冲击性能。