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溶胶-凝胶制备的Al2O3涂层抗原子氧侵蚀性能研究 总被引:1,自引:0,他引:1
以异丙醇铝(Al(C3H7O)3)为先驱物,水为溶剂,HNO3做胶溶剂制得了稳定、均一的Al2O3溶胶,浸涂在聚酰亚胺和银薄膜表面干燥后获得了致密透明的涂层。采用空间综合环境地面模拟设备对试样进行了原子氧暴露实验。结果表明:溶胶.凝胶制备的Al2O3涂层抗原子氧侵蚀性能优异,抗原子氧侵蚀性能比聚酰亚胺基体提高了2个数量级以上。经FTIR和XPS分析表明:在原子氧暴露后涂层表面生成了一层Al2O3,阻止了原子氧对基体材料的进一步侵蚀。涂覆涂层后基体的光学性能没有受到影响。实验证明溶胶.凝胶制备抗原子氧侵蚀的防护涂层是一种行之有效的方法。它工艺简单,可涂覆形状复杂、大面积的器件。 相似文献
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以异丙醇铝(Al(OC3H7)3)和氧氯化锆(ZrOCl2·8H2O)为原料,采用溶胶-凝胶法在γ-TiAl基合金表面制备Al2O3/ZrO2涂层。研究涂层试样和空白试样在1000℃静态空气中的长期氧化行为和循环氧化行为。结果表明:Al2O3/ZrO2涂层降低了该合金的氧化速率,提高了合金的抗循环氧化能力。对涂层的作用机制进行了探讨。 相似文献
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采用溶胶-凝胶法在钨纤维的表面制备Al2O3涂层,用热分析(TG-DSC)、X射线衍射(XRD)、扫描电镜(SEM)和电子能谱仪(EDS)等方法研究钨纤维表面Al2O3涂层在不同干燥工艺、不同PVA添加量和不同煅烧温度下的组织特征。结果表明:采用分步干燥工艺可以避免涂层团聚和开裂;溶胶制备中加入体积分数为5%的聚乙烯醇(PVA)可以提高溶胶稳定性,有利于制备均匀且无裂纹的Al2O3涂层;钨纤维表面Al2O3涂层制备的最佳煅烧温度为950℃;采用Al2O3涂覆的钨纤维抗氧化温度提高了120℃,氧化增重减少了约9%。 相似文献
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溶胶-凝胶法制备的Al2O3涂层及其对γ-TiAl合金的高温氧化防护 总被引:1,自引:0,他引:1
以异丙醇铝(Al(OC3H7)3)为原料,采用溶胶-凝胶法在γ-TiAl基合金表面制备Al2O3涂层.以空白样品做对照,研究涂层的作用机制以及涂层对γ-TiAl基合金1 000 ℃高温氧化行为的影响.结果表明:采用浸涂工艺制备的涂层表面均匀、无裂纹,主要由γ- Al2O3相组成,厚度约为0.8 μm;等温氧化110 h后,空白试样和Al2O3涂层试样的氧化抛物线速率常数分别为4.85×10-12 和 3.31×10-13 g2/(cm4-s),涂层明显提高合金的抗氧化能力及抗循环氧化能力;空白样品上形成的氧化膜出现分层现象,而在涂层样品的Al2O3涂层中存在金红石型TiO2和α-Al2O3混合物. 相似文献
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目的提高304不锈钢表面的耐蚀性。方法选取304不锈钢为基体,采用溶胶凝胶法,制备陶瓷涂层。以异丙醇铝为前驱体制备Al2O3溶胶。通过XRD对干凝胶粉末进行物相分析,并对陶瓷涂层的耐腐蚀性能进行了研究,分析了制备溶胶的原料配比、胶溶剂的加入量、不同烧结温度对陶瓷涂层表面形貌和耐腐蚀性能的影响。结果 n异丙醇铝:n无水乙醇:n去离子=1:1:100、水浴温度70℃、p H=4~5时搅拌制备出的溶胶,在600℃下保温30 min可制备出无裂纹、均匀、高纯、表面质量良好的陶瓷涂层,陶瓷涂层为高纯的Al2O3。结论陶瓷涂层在Na Cl溶液和盐雾中表现出优异的耐蚀性。 相似文献
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采用溶胶-凝胶法在铝合金表面制备无机耐磨陶瓷涂层,考察了不同配比的SiO2溶胶对涂层表面质量、显微硬度以及与基体的界面结合情况的影响,并研究了陶瓷涂层的形成机制。结果表明,当SiO2溶胶的配比中,正硅酸乙酯与水、乙醇的摩尔比为1∶1∶10时,得到的涂层表面平整紧实,显微硬度最高。微观分析发现涂层和基体发生了一定程度的化学反应,涂层中出现了AlN、Al3SiCr、Al0.7Fe3Si0.3等新相,表明界面出现过渡层。溶胶与陶瓷粉体制备的复合涂料,使得涂层能在较低温度下完成烧结,从而在铝合金表面得到致密的陶瓷涂层。 相似文献
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Jung-Han LEE Jong-Do KIM Jin-Seok OH Seo-Jeong PARK 《中国有色金属学会会刊》2009,19(4):946-951
Al coated steel sheets with excellent heat resistance, thermal reflection, and corrosion resistance are widely used in various applications. The laser weldability of the Al coated steel sheet for full penetration welding was reported. The phenomenon caused by intermixed aluminum and behavior of aluminum in the weld were investigated. Al coated steel sheets that have various thickness and coating mass were prepared for laser welding. The effects of parameters such as welding conditions and Al coating conditions were investigated. Al content mixed in the weld after laser welding was evaluated, and then a correlation between the mixed Al and mechanical properties was investigated. The results show that the Al-rich zones which have Fe-Al intermetallic compounds are found in the weld. The intermetallic compounds cause the decreased strength of the weld. 相似文献
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Y.M. Wang H. Tian D.L. Quan L.X. Guo J.H. Ouyang Y. Zhou D.C. Jia 《Surface & coatings technology》2012
High infrared emissivity coatings were prepared on 304 steel by pyrolyzing reactions with poly(hydridomethylsiloxane) (PHMS) and Al/HW powders. The microstructure, phase and chemical composition of the coatings were determined by SEM, XRD and EDS techniques. The infrared emissive properties at wavelength 3–20 μm of the coatings pyrolyzed at 600 and 800 °C on the steels were investigated. It was found that the 800 °C pyrolyzed coating exhibited a slightly higher infrared emissivity value than that of the 600 °C pyrolyzed coating, which was attributed to the complete conversion of Al to Al2O3 and pyrolysis of PHMS into SiO2, as well as the enhancement of photon emission by HW. Comparatively, the uncoated steel indicated a much lower infrared emissivity value about 0.2 in 8–14 μm. 相似文献
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研究了施加稳恒磁场(0~1 T)对碳钢表面电镀Ni-W合金的影响。测定了不同方向、不同强度稳恒磁场下的电流效率、合金组成及镀层硬度,并用X射线衍射对镀层的微观结构进行了分析。对实验结果进行了分析讨论,找出了稳恒磁场对上述性能的影响规律。结果表明:与不施加磁场相比,施加磁场后镀层的含钨量上升:当磁场方向垂直于电场方向(B⊥J),B=1.0 T时,含钨量上升了约11%;当磁场方向平行于电场方向(B∥J),B=1.0 T时,含钨量上升了约13%;镀层的非晶化程度增强;镀层的硬度提高、孔隙率下降;但Ni-W合金电沉积的电流效率降低。 相似文献
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Continuous, uniform Hf(Ta)C coating was co-deposited on carbon/carbon composites by chemical vapor deposition. The phase composition, microstructure and ablation properties of the Hf(Ta)C coating are investigated. Results show that the as-prepared coating is a biphasic coating consisting of HfC and HfTaC2. The particle-stacked structure is effective to produce a crack free Hf(Ta)C coating and good adhesion between the coating and C/C composites. The Hf(Ta)C coating can effectively protect C/C composites from ablation. After 60 s ablation, the mass and linear ablation rates of coated sample are 0.01 ± 0.02 mg cm−2 s−1 and 0.46 ± 0.02 μm s−1, respectively. 相似文献
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Al-Mg合金镀层的制备与性能 总被引:3,自引:0,他引:3
利用AlCl3 LiAlH4 MgBr2有机溶剂体系在碳钢基体上电沉积出Al-Mg合金镀层,并对不同沉积电流密度下Al-Mg镀层的表面形貌、成分、结构、厚度、结合力和耐蚀性进行了研究。结果表明:沉积出的铝镁合金镀层表面光滑、均匀、致密;膜层中的镁含量随沉积电流密度的增加而增大,且以Al-Mg固溶体形式存在,并按(200)面的结构生长;随沉积电流密度的增加,铝镁合金镀层的厚度与晶格常数呈线性增大;在3.5%NaCl溶液中的耐蚀性呈先增大后减小的规律;Al-Mg镀层与碳钢基体的结合力良好,均大于50 N;Al-Mg镀层的沉积速率、结合力和耐蚀性均高于相同沉积条件下的纯铝镀层;Al-Mg合金镀层沉积的最佳电流密度为0.75~1.50A/dm2。 相似文献
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为实现铝合金结构材料在高温环境下的热防护,采用溶胶-凝胶法在铝合金表面制备无机锆溶胶涂层。采用正丙醇锆和冰醋酸制备了稳定性良好的锆溶胶,研究了聚乙烯基吡咯烷酮(PVP)含量对锆溶胶粒子大小和黏度的影响规律,并分析了PVP对溶胶粒子的作用机制。添加60%(质量分数,下同)SiO_2填料制备无机涂层,并对涂层进行烧蚀考核,对比研究了不同胶粘剂对涂层结构和热防护性能的影响。根据涂层在烧蚀考核中的宏微观响应,分析了无机涂层在高温下的热防护机制。结果表明:冰醋酸添加量为2.6 g时,锆溶胶稳定性最好;添加质量分数为7%PVP优化后,锆溶胶粒子大小均匀并且具有最好的涂覆性;3种不同胶黏剂基涂层在1300℃火焰烧蚀30 s后基体均未发生破坏,水玻璃基涂层烧蚀后发生剥落;较其它胶黏剂涂层,锆溶胶基涂层具有最好的热防护效果。烧蚀过程中,锆溶胶粒子在高温下发生脱水缩合形成纳米氧化锆粒子,弥散分布在填料周围,与填料产生良好的协同隔热作用,使涂层整体具有良好的高温热防护性能。 相似文献
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King Peter C. Brownrigg Allan Long John M. Reynoldson Ray W. 《Journal of Materials Engineering and Performance》2004,13(4):431-438
CrN coatings were formed on plain carbon steel by prenitrocarburizing, followed by thermoreactive deposition and diffusion
(TRD) in a fluidized bed furnace at 570 °C. During TRD, Cr was transferred from Cr powder in the fluidized bed to the nitrocarburized
substrates by gas-phase reactions initiated by reaction of HCl gas with the Cr. The microstructural processes occurring in
the white layer, caused by N diffusion toward the surface during this stage were studied. This study compares TRD atmospheres
employing inert gas and HCl or inert gas, H2, and HCl. Surface characterization was performed by scanning electron microscopy (SEM), x-ray diffraction (XRD), and glow-discharge
optical-emission spectroscopy (GDOES).
This paper was presented at the 2nd International Surface Engineering Congress sponsored by ASM International, on September
15–17, 2003, in Indianapolis, Indiana, and appears on pp. 467–75 of the Proceedings. 相似文献