钛合金表面抗氧化玻璃-陶瓷涂层研究进展

抗氧化性差是影响钛合金在航空航天领域广泛应用的重要因素,提高抗氧化性成为钛合金研究的一个主要方向。玻璃-陶瓷涂层具有较宽的软化温度范围、良好的化学稳定性、高的机械强度,可作为钛合金高温抗氧化涂层。总结了钛合金表面抗氧化涂层材料的性能要求及玻璃-陶瓷抗氧化涂层材料的优缺点,综述了国内外钛合金表面抗氧化玻璃-陶瓷涂层的研究进展;展望了钛合金表面抗氧化玻璃-陶瓷涂层的发展方向。     

固体氧化物燃料电池合金连接体表面改性研究进展

铁素体不锈钢是目前用作固体氧化物燃料电池(SOFC)连接体最理想的合金材料。但问题在于铁素体不锈钢在SOFC工作环境下易被氧化,尤其是在阴极侧Cr向外扩散,易导致阴极Cr中毒问题。为了克服以上弊端,国内外很多学者对合金表面改性做了大量研究,本文综述了近些年在该领域的研究成果。     

FeCrAl合金表面高温抗氧化陶瓷涂层的制备

用粘结料与Cr2O3制成料浆,用喷涂涂覆于FeCrAl合金表面,在空气中1 300℃熔烧制备了耐高温（1 200℃）抗氧化陶瓷涂层.用扫描电子显微镜,电子探针显微分析仪,X射线衍射仪,热膨胀仪等测试手段对涂层以及涂层与基体界面处进行表征.探讨了陶瓷涂层样品高温抗氧化性能的机理,获得了具有良好高温抗氧化性能的陶瓷涂层配方,其粘结料与Cr2O3的质量比为1;0.5.结果表明：在空气中1 200℃,360 h抗氧化实验后,这种涂层样品的氧化质量增加约为基体合金的1/22.揭示了涂层高温抗氧化性能与涂层的组成、显微结构之间的关系.     

固体氧化物燃料电池金属连接体保护涂层的制备方法概述

不锈钢合金是目前固体氧化物燃料电池(SOFC)常用的连接体材料,在使用过程中仍存在的主要问题是易被氧化;以及阴极侧Cr易扩散而导致阴极Cr中毒,致使电堆的电性能衰减过快。为解决上述问题,常在金属连接体表面添加致密的保护涂层。为得到成分均一﹑结构致密﹑厚度可控﹑导电性能良好且与基体结合牢固的涂层,很多方法可被采用。本文综述了SOFC金属连接体保护涂层的制备方法,将其分为物理法和化学法两大类。对各制备方法的工艺与性能之间的关系进行了讨论与比较,并提出了SOFC金属连接体保护涂层制备的主要问题和研究方向。     

涂覆工艺对金属基陶瓷涂层高温抗氧化性能影响的研究

将陶瓷粘结料与Cr2O3或重烧MgO制成料浆,采用刷涂、浸渍和喷涂三种涂敷方法和高温熔烧工艺制备金属基Cr2O3或MgO质高温抗氧化陶瓷涂层。研究了三种涂敷方法、涂层厚度对涂层试样高温抗氧能力的影响规律。结果表明:当料浆组成、涂层厚度和熔烧制度相同条件下,采用喷涂工艺所制备的涂层试样具有最佳的抗氧化能力,且Cr2O3和MgO质陶瓷涂层在1200℃、30h的抗氧化能力分别是金属基体的约62倍和16倍。采用SEM对涂层的显微结构进行了表征,揭示涂覆工艺与涂层结构和抗氧化能力之间的关系。     

镍基高温合金陶瓷涂层的制备及性能表征

以Cr2O3粉、玻璃料及黏土为原料制成料浆,通过喷涂将其涂覆在镍基高温合金GH44的表面,采用热化学反应法于1050°C保温10min,熔烧制备出高温陶瓷涂层。通过扫描电镜和X射线衍射分析了高温陶瓷涂层的表面和截面形貌以及相组成,对涂覆陶瓷涂层的镍基合金的抗热震性能、抗氧化性能以及高温疲劳性能进行了测试。结果表明,陶瓷涂层结构致密,与基体结合牢固,具有良好的抗热震性能。涂覆陶瓷涂层的镍基合金其高温抗氧化性相对于基体提高了6倍以上,其高温疲劳性能明显改善。     

Cr2O3/NiO对金属基高辐射陶瓷涂层结合性能的影响

以熔块、粘土、ZrSiO4为基料,通过添加不同比例的Cr2O3/NiO,采用高温熔烧法在不锈钢金属基表面制备出结合性能较好的高辐射率陶瓷涂层。利用XRD、SEM和红外辐射测试等方法对涂料的物相、结构形貌和红外辐射性能作了分析测试,结果表明:合理的加入Cr2O3/NiO经高温煅烧后,其可增强涂层材料对金属基的润湿性,NiO还可与基材发生物化反应,从而使涂层与基体之间形成牢固的结合。同时Cr2O3/NiO能与涂层材料中的其他成份形成立方尖晶石结构,有利于增大涂层辐射率。     

环境障涂层材料及结构的研究进展

陶瓷基复合材料(CMC)具有低密度、高强度、抗氧化、抗烧蚀和优异的高温力学性能,在未来的航空航天领域前景十分广阔。环境障涂层(EBC)是为了提高陶瓷基复合材料部件在高温腐蚀环境下稳定性的表面防护涂层。EBC研究主要集中在涂层材料、涂层结构等方面,目的是为了提高涂层的高温稳定性和耐腐蚀性能。介绍了环境障涂层的发展历程,以及涂层材料和涂层结构方面的研究进展。     

化学世界

SiC/SiC陶瓷复合材料具有低密度、高强度、抗氧化、抗烧蚀、优异的高温力学性能，在未来的航空航天领域前景十分广阔。环境障涂层（Environment barrier coatings，EBC）是为了提高陶瓷复合基材料部件在高温腐蚀环境下稳定性的表面防护涂层。EBC研究主要集中在涂层材料、涂层结构等方面，大大提高涂层的高温稳定性和耐腐蚀性能。本文主要介绍了环境障涂层的发展历程，以及在涂层材料和涂层结构上的研究进展。     

碳纤维增强碳复合材料高温抗氧化硅基陶瓷涂层的研究进展(英文)

碳纤维增强碳(carbon fiber reinforced carbon,C/C)复合材料抗氧化问题一直是国际材料界研究的热点。硅基陶瓷作为C/C复合材料抗氧化涂层,是目前研究最深入的涂层体系。综述了国内外近几年C/C复合材料高温抗氧化硅基陶瓷涂层的研究进展,总结了C/C复合材料高温抗氧化硅基陶瓷涂层的制备工艺和对已有工艺的改进方法,分析了硅基陶瓷涂层在高温空气中、燃烧环境中的氧化失效机理。结合硅基非氧化物陶瓷(SiC,Si3N4等)环境障碍涂层的发展,展望了C/C复合材料在复杂环境中抗氧化涂层的研究方向。     

MnxCo3-xO4 spinel coatings: Controlled synthesis and high temperature oxidation resistance behavior

A controllable method for the synthesis of Mn_xCo_3-xO₄ (x = 0.4, 0.8, 1.0, 1.2) spinel coatings with unique microstructures and high-temperature oxidation resistances for solid oxide fuel cells is crucially desired. Herein, we report the synthesis and analysis of synthesized coatings with different phase compositions of ferritic stainless steel interconnects. The coatings are fabricated using a sol-gel dip-coating method. Multiple experimental results confirm that the Mn_xCo_3-xO₄ coatings exhibit the advantages of having fine grains and uniform density. Furthermore, the as-prepared Mn_1.2Co_1.8O₄ coating has a low coefficient of thermal expansion (11.98 × 10^-6 K^-1), matching that of ferritic stainless steel, which effectively improves the anti-stripping property of the materials. In particular, oxidation tests illustrate that the oxidation weight gain of this coating decreased by 84.4% compared with bare ferritic stainless steel after 3600 h. The area-specific resistance (ASR) results indicate that the ASR value of the Mn_1.2Co_1.8O₄-coated sample reduced by about 70% compared with those of the ferritic stainless steel samples, which demonstrates its desirable high-temperature oxidation resistance property. It is hoped that this work stimulates new research ideas for the development of spinel oxide coating.     

Interconnect materials for next-generation solid oxide fuel cells

Highly-efficient solid oxide fuel cell (SOFC) systems are gaining increased attention for future energy conversion applications. Many planar SOFC stack designs utilise ferritic stainless steel (FSS) interconnect components. During operation, surface corrosion of FSS interconnects degrades stack operation by increasing electrical resistance and introducing other deleterious material interactions. To minimise these effects, various surface modifications and coatings are currently under investigation. Two of these methods under development for this application are: metal organic chemical vapour deposition (MO-CVD); and, large area filtered arc deposition (LAFAD). SOFC interconnect-relevant corrosion behaviour of an MO-CVD coating on Crofer 22 APU, AL453, Fe30Cr and Haynes230, and complex, amorphous LAFAD AlCrCoMnTiYO coatings on FSS 430 were investigated. Both of these surface modifications and coatings exhibit significantly improved corrosion protection as compared with uncoated FSS samples.     

高铬铁素体不锈钢在硫酸和湿法磷酸生产中的应用

在当今金属镍价格不断上涨的情况下，开发和使用不合贵重金属镍而力学性能和耐腐蚀性能都十分优良的高铬铁素体不锈钢具有很重要的经济意义：调整高铬铁素体不锈钢中的碳含量，可改变其物化性能，介绍了超低碳、低碳和高碳高铬铁素体不锈钢的特点，以及它们在高温浓硫酸和湿法磷酸生产设备中的应用情况。     

热浸渗铝硅合金Q235钢的抗高温腐蚀性能研究

研究了Q2 35钢经热浸渗纯铝和不同硅含量的铝合金后的抗高温氧化和抗热腐蚀性能 ,比较了纯铝渗层和铝硅合金渗层的抗高温腐蚀性能 ,并分析了硅元素的作用。结果表明 ,Q2 35钢经热浸渗纯铝和铝硅合金后的抗氧化性能基本接近不锈钢 ,而抗热腐蚀性能则明显优于不锈钢     

凹凸棒土基高温防脱碳涂层的研究

为了避免钢在热处理过程中表面发生氧化脱碳,以凹凸棒土(ATP)为主要原料,加入一定比例的Al2O3、SiC和Cr2O3等粉末和硅酸钾水溶液配制成涂料,刷涂于60Si2Mn和GCr15两种钢材表面并在60℃下烘干2 h形成涂层,然后对此涂层进行热处理温度850～1 150℃、保温时间30～120 min的高温防脱碳试验,并采用光学显微镜和X射线衍射仪等对涂层的保护效果和保护机制进行了研究。结果表明:该涂层能够显著降低这两种钢材的脱碳层厚度,并且随着保温时间的延长和加热温度的升高,涂层防脱碳性能仍然保持良好;该涂层通过形成致密覆盖层以及涂层中SiC的氧化反应而对钢材起到防脱碳作用。     

不锈钢管在聚酯生产行业中的选用

采用慢应变速率拉伸试验、扫描电镜断口分析以及金相显微组织分析检测等方法对0Cr13Al铁素体不锈钢及2205双相不锈钢在酸性介质中应力腐蚀开裂行为进行了研究。并评定不锈钢管在腐蚀性介质中应力腐蚀开裂的敏感性。为在聚酯生产行业中选择容器用钢提供依据。结果表明,拉伸试样全部断裂在焊缝或热影响区。试样断口形貌呈准解理断裂和韧性断裂。2205双相不锈钢的应力腐蚀敏感性比0Cr13Al铁素体不锈钢低。     

High Temperature Cyclic Oxidation Resistance of Iron Chromium Base Alloys

The cyclic oxidation behavior of an experimental stainless ferritic steel, without molybdenum and with copper‐aluminum‐titanium‐lanthanum additions, developed for solid oxide fuel cell applications, was evaluated and compared with the oxidation behavior of commercial austenitic and ferritic stainless steels. For the cyclic oxidation tests, the steel samples were tested at temperatures ranging from 600 to 800 °C. The experimental ferritic stainless steel showed the highest cyclic oxidation behavior among the studied steels at 700 °C and 800 °C, presenting a parabolic and logarithmic kinetics, respectively.     

凝胶--封孔法制备不锈钢表面陶瓷膜层

为改善不锈钢的抗高温氧化性和耐磨性,拓宽其应用范围,采用凝胶－－封也法在不锈钢表面制得陶瓷膜层。介绍了该方法的工艺过程,探讨了电沉积及封孔机理以及各因素对成膜过程的影响。该方法所得陶瓷膜层光滑平整,具有好的耐磨性及抗高温氧化性。     

Oxidation Behavior of Ferritic Steel Alloy Coated with Highly Dense Conducting Ceramics by Aerosol Deposition

Conducting La_0.8Sr_0.2MnO₃ (LSM) ceramic layers with a thickness of ∼10 μm were deposited on ferritic stainless steel (SS) by aerosol deposition for use as an oxidation resistance coating layer in the metallic interconnects of solid oxide fuel cell. The microstructural evolution and electrical properties of the LSM-coated SS were observed. The coated layers were fairly dense without pores or cracks, and maintained good adhesion even after oxidation at 800°C for 1000 h in air atmosphere. The surface of the bare SS after heat treatment at 800°C for 1000 h was covered with Cr-containing oxide scales, and the electrical conductivity was sharply decreased. However, the LSM-coated SS alloy showed a surface microstructure with almost no chromic oxide formation and maintained good electrical conductivity after the heat treatment. Close observation of the interface between LSM and SS indicated the presence of ∼500-nm-thick Cr₂O₃ and MnCr₂O₄ spinel phase, which may have caused the long-time deterioration of the interconnector performance. The area-specific resistance of the LSM-coated alloy after heat treatment at 800°C for 1000 h was 10.4 mΩ·cm².     

Investigation of Impactors on Cell Degradation Inside Planar SOFC Stacks

The impactors on cell degradation inside planar SOFC stacks were investigated using both coated and uncoated Fe–16Cr alloys as the interconnects under stable operating conditions at 750 °C and thermal cycling conditions from 750 to 200 °C. It was found that cell degradation inside the stack is primarily dependent on the interfacial contact between the cathode current‐collecting layer and the interconnect. Additionally, cell degradation is found to be independent of the high‐temperature oxidation and Cr vaporization of the interconnects during stack operation, as the stacks are well sealed. The coating on the interconnect can further improve the contact between the cell cathode and the interconnect when the latter is properly embedded into the current‐collecting layer.