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1.
金属材料难以避免地会经常产生表面吸附与腐蚀,从而造成材料表面腐蚀失效,给生命安全与社会经济造成巨大的危害与损失,研发高效的金属表面防护涂层是一种关键技术手段。利用自由基共聚法,制备了兼具高疏水性与优异的防腐功能的有机硅-丙烯酸酯复合树脂材料。通过核磁共振氢谱、原子力显微镜、接触角以及腐蚀溶液浸泡等测试手段,对复合材料进行了化学结构、形貌及性能的测试和表征。研究结果表明:复合涂层的表面呈现典型的纳米级粗糙结构,分布着微纳米富硅储液池;复合树脂在金属表面成膜后可显示很高的疏水特性,其表面水滴的前进、后退接触角(θAθR)分别为106和94 °,优异的疏水性能使其可应用于高效油水分离;该涂层对常见液体以及脱氮假单胞菌Pseudomonas sp均显示出优异的防吸附性能,特别是该复合树脂涂层还具有良好的抗酸、碱、盐腐蚀性和机械稳定性。上述结果表明,有机硅-丙烯酸酯复合树脂涂层在诸多领域均具有较高的应用潜力。  相似文献   
2.
《Ceramics International》2022,48(1):754-759
Thermal control coatings (TCCs) are an essential part of the thermal control systems in the spacecraft. Solar absorptance and emittance are the key performance parameters of TCCs. To develop an ultra-low solar absorption and stable inorganic TCCs for surface radiator, different TCCs were prepared by co-sintering ZnO and SiO2 nanoparticles to form Zn2SiO4/SiO2 pigment in this work, and the optical properties and radiation stability were systematically studied. It is found that the coating based on composite pigment has high reflectivity in the ultraviolet band and excellent optical performance possessing the low solar absorption of 0.06. In addition, the Zn2SiO4/SiO2 coating demonstrates the highest proton and electron radiation stability because that SiO2 between Zn2SiO4 particles acts as the relaxation center of the defects caused by radiation.  相似文献   
3.
《Ceramics International》2022,48(4):5091-5099
The impact of the addition of TiO2 nanoparticles and nanowires on the morphology, phase characteristics, contact angle, and electrochemical performance of chemically bonded phosphate ceramic coatings (CBPCs) was investigated. The chemical composition and surface morphology of the TiO2 nanoparticle and nanowire modified with and without (heptadecafluoro-1,1,2,2-tetradecyl) trimethoxysilane were characterized. Results indicated that the hydrophobic –CF2– and –CF3 groups were successfully introduced into the TiO2 nanoparticles and nanowires after modification. Corrosion resistance of CBPCs with TiO2 was evidently improved compared with that without TiO2. Such improvement was mainly due to the combined effects of low surface energy materials and micro/nano structures. In addition, CBPCs with TiO2 nanowires exhibited higher hydrophobicity and corrosion resistance than those with TiO2 nanoparticles because of the special columnar structure of the nanowires.  相似文献   
4.
Heat transfer within ceramic feedstock powders is still unclear, which impedes optimization of the thermal and mechanical properties of the thermal sprayed coatings. The microspheres (yttria-stabilized zirconia YSZ and lanthanum zirconate LZO) were prepared via the electro-spraying assisted phase inversion method (ESP). The thermal properties of the two ESP microspheres and a commercial hollow spherical powder (HOSP) were investigated by using theoretical, experimental, and simulation methods. Thermal conductivity of the single microsphere was estimated via a novel nest model that was derived from the Maxwell-Eucken 1 and the EMT model. Thermal conductivity of a single YSZ/LZO-ESP microsphere prepared at 1100–1200 °C was within 0.36–0.75 W/m K, which was ~ 20 % lower than that of a single YSZ-HOSP microsphere with a similar porosity. Heat flux simulation showed that high tortuosity around the multi-scaled voids of the ESP microsphere led to a more efficient decrease in thermal conductivity compared with total porosity.  相似文献   
5.
纳米纤维素及其在水性涂料中的应用研究进展   总被引:1,自引:1,他引:0       下载免费PDF全文
纳米纤维素具有高长径比、高结晶度、高杨氏模量、高强度等优点,加之其具有生物质材料的轻质、可降解及可再生等特性,使其成为一种改善水性涂料机械、光学、耐水等性能的优异选择。本文综述了纳米纤维素制备和改性方法,详细论述了纤维素纳米纤丝(CNF)和纤维素纳米晶体(CNC)对水性聚氨酯和水性丙烯酸涂料的性能改善机理及其应用研究进展。最后总结了纳米纤维素复合水性涂料研究现存的问题,并总结了未来的研究方向。  相似文献   
6.
Pursuing novel thermal barrier–coating materials with lower thermal conductivity and high-temperature stability can simultaneously improve the working efficiency and service temperature of a gas turbine. In this study, a series of high-entropy RE2(Y0.2Yb0.2Nb0.2Ta0.2Ce0.2)2O7 (RE = La, Nd, Sm, Gd, Dy, and Er) oxides were prepared though solid-state reaction. Through tuning the rare-earth cations, an order–disorder transition occurs from certain partially ordered weberite structure (C2221) to disordered defective fluorite structure (Fm3¯ $\bar{3}$m). All the high-entropy RE2(Y0.2Yb0.2Nb0.2Ta0.2Ce0.2)2O7 oxides possess low thermal conductivity in the range of 0.91–1.34 W m−1 K−1 at room temperature, which can be attributed to increased lattice anharmonicity and disorder, resulting in additional phonon scattering. Herein, we proved that the incorporation of heterovalent cations at B-sites in high-entropy A2B2O7 crystals is an effective strategy to reduce the thermal conductivity without compromising the decrease of oxygen vacancy. Moreover, the high-entropy RE2(Y0.2Yb0.2Nb0.2Ta0.2Ce0.2)2O7 oxides show the relatively higher thermal expansion coefficients of 10.3–10.7 × 10−6°C−1 and excellent phase stability at elevated temperatures.  相似文献   
7.
张昆  李美求  魏轲  冯鹏云 《焊接》2022,(4):9-16
在油气开采作业过程中,高压流动介质中固体颗粒对结构件的冲蚀磨损而引起综合表面性能下降,造成了基材损坏,严重影响了关键设备的使用寿命。冲蚀最先被破坏损伤的是材料表面,表面沉积涂层处理技术是改善特定应用中裸漏零部件特性的有效方法。提高表面涂层性能是设备抗冲蚀常用的手段,正越来越多地用于石油和天然气行业中。根据材料本身的物理特性,文中从塑性材料和脆性材料的分类评述了其各自冲蚀机理,综述了利用热喷涂技术、激光熔覆技术、电镀技术及气相沉积等技术制备抗冲蚀磨损涂层的研究现状和进展,介绍了这些技术在制备涂层过程和使用的主要仪器设备。提出了应用多种工艺技术交叉来制备抗冲蚀磨损涂层的方法和以后研究的重点。并对涂层抗冲蚀磨损领域未来的研究方向进行了展望,为固液或气固等多相流动介质的高压石油装备抗冲蚀设计提供参考。  相似文献   
8.
目的 建立热障涂层寿命预测模型,并研究涂层寿命预测与各种应力应变信息的相关性。方法 首先利用带热障涂层圆管试验结果,将涂层界面简化为余弦曲线,建立了相应的二维轴对称有限元模型;然后根据热障涂层疲劳试验结果,结合线性疲劳累积理论和Manson–Coffin低周疲劳模型,建立了热障涂层的寿命预测模型,并将拟合问题转化为寻优问题,使用遗传算法确定寿命预测模型中的系数;最后基于热障涂层试验的微观照片确定出危险点位置,选取正向、剪切、等效和通过二向应力应变分析方法提取垂直于余弦曲面形貌的11种应力应变信息进行寿命预测,并分析了寿命预测的最大误差和平均误差,对分析的结果进行了验证。结果 采用等效应变范围进行涂层寿命预测的最大误差和平均误差最小,分别为50%和21%,涂层寿命与等效应力的相关性最大。采用等效应变进行寿命预测的结果与文献中的结果相比,最大误差降低了169.1%,整体的寿命预测值从±2倍分散带之内缩小到了±1.5倍分散带之内。采用等效应变范围进行不同工况下的涂层寿命预测,预测结果为130次循环,试验结果为160次循环,寿命预测的结果较好。结论 证明了所建立模型的正确性与准确性,为涂层寿命...  相似文献   
9.
《Ceramics International》2022,48(22):32973-32985
Multilayer structure design is one of the most promising methods for improving the comprehensive performance of AlCrN-based hard coatings applied to cutting tools. In this study, four types of AlCrSiN/AlCrVN/AlCrNbN multilayer coatings, with different modulated thicknesses, were deposited to investigate their microstructure, mechanical, tribological, and oxidizing properties. All multilayer coatings exhibited grain growth along the crystallographic plane of (200) with a NaCl-type face-centered cubic (FCC) structure. The results show that, as the modulation thickness decreases from ~35 nm to ~10 nm, (1) the grain refinement effect is increasingly evident; (2) all multilayer coatings show a hardness of >30 GPa and an elastic modulus of >300 GPa. Both the ability to resist elastic strain to failure and the plastic deformation of multilayer coatings increase. In addition, their resistance to cracking reduces; (3) the wear rates of these multilayer coatings reduce successively from 1.78 × 10?16 m3 N?1 m?1 to 7.7 × 10?17 m3 N?1 m?1. This is attributed to an increase in self-lubricating VOx and a decrease in adhesives from the counterparts; (4) the best high-temperature oxidation resistance was obtained for the multilayer coating with a modulated thickness of ~15 nm.  相似文献   
10.
《Ceramics International》2022,48(5):6372-6384
Sm2O3-HfO2 series ceramics were synthesized at high temperature using the solid-state reaction. The phase stability, thermo-physical and infrared emission properties of Sm2Hf2O7 (SHO) and Sm2Hf2O7-44.83 wt%HfO2 (25S/H) composite ceramics were comparatively investigated. Furthermore, their calcium magnesium aluminosilicate (CMAS) corrosion was conducted at 1250°C for different times. The results reveal that both SHO and 25S/H ceramics have excellent phase stability at 1600°C as well as excellent sintering resistance. SHO still exhibits slightly lower thermal conductivity and lower hardness and Young's modulus, higher thermal expansion coefficient (CTE) and fracture toughness as well as higher infrared emittance (0.899 at 800°C) than 25S/H composite with the excessive HfO2 inside. Both SHO and 25S/H ceramics react with CMAS to form a relatively compact reaction layer, which can effectively prevent the penetration of CMAS. These results preliminarily indicate that SHO ceramic can be proposed as an alternative material of the traditional YSZ for high-temperature thermal protective applications thanks to its compatible performance of low thermal conductivity and high infrared radiation, etc.  相似文献   
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