直流磁控溅射Cr/Cr2O3金属陶瓷选择吸收薄膜的研究

光谱选择吸收薄膜的制备是太阳能集热器高效吸收太阳能的关键技术。本文首先研究了磁控溅射Cr／Cr2O3金属陶瓷选择吸收膜中，氧气流量、溅射靶电流等基本参数对靶电压的影响，然后对不同氧气流量和靶电流条件下制备的Cr／Cr2O3金属陶瓷选择吸收膜的光学常数采用椭偏仪进行了研究，得到了不同工艺条件下的Cr／Cr2O3金属陶瓷薄膜的光学常数，最后经过膜系设计和试验镀制，制备出了室温下吸收率α≥95％、发射率ε≤5％的高性能太阳能选择吸收膜。     

光谱选择性太阳能吸收涂层的研究进展

选择性吸收涂层技术是公认的太阳能光热转换较为核心的技术,它对提高太阳能热转换效率,大规模推广太阳能光热应用起着至关重要的作用。主要综述了光谱选择性太阳能吸收涂层的分类及制备方法。     

太阳能光谱选择性吸收涂层研究进展

采用高速研磨搅拌加水掺法,制备出含不同质量分数的纳米SiO2混杂纤维（NSPF）混凝土,通过力学试验测得立方体抗压强度、劈裂抗拉强度、变形性能及冲击韧性。通过与钢纤维／聚丙烯二元混杂纤维（SPF）混凝土进行比较,NSPF混凝土的立方体抗压强度、劈裂抗拉强度、疲劳次数、弹性模量、初裂抗冲击次数和破坏抗冲击次数分别提高10...     

等离子喷涂法制备黑铬太阳能选择性吸收涂层

采用等离子喷涂法制备了黑铬太阳能选择性吸收涂层,采用XRD、SEM等测试方法对涂层的物相、微观结构、太阳能吸收性能进行了表征。对涂层进行了打磨,并在涂层表面制备SnO2选择性透过薄膜。研究表明,采用等离子喷涂方法制备的黑铬涂层吸收率为0.93,发射率为0.88,经打磨处理后,发射率降至0.76。添加SnO2薄膜后,涂层吸收率变化小,发射率降至0.50。热震实验表明该涂层具备良好的抗热震性能。     

Microstructure Formation of HVOF Sprayed WC-Ni Coatings Deposited on Low Alloy Steel

A low alloy steel was coated with WC-Ni by the High Velocity Oxy-Fuel process, in order to increase the wear resistance and corrosion resistance of the material. The microstructure of the coating was determined using various techniques, such as SEM, TEM, EDAX, EPMA and X-ray diffraction methods

During spraying, the WC-Ni powder granules were heated to above the melting point of Ni, before arriving at the substrate surface. The molten Ni dissolves WC rapidly, forming Ni-W-C liquid alloys. Some C and some W are removed from the WC particles by oxidation. When each droplet strikes the steel substrate, a pancake-shaped splat forms, and solidifies with a rapid cooling rate. The structure is built up by the progressive deposition of the splats to produce a continuous coating. The Ni-W-C metallic matrix of the coatings consists of two basic structural types, Ni-rich material with a grain size of 10 - 100 nm, and a FCC crystal structure with a lattice parameter larger than that of Ni indicating the presence of dissolved W and C. The other metallic phase is W-rich, with a grain size less than 10 nm, and in some regions it appears to be amorphous. Dispersed within this material there were sometimes small crystals of W and W₂C. In the initial powder the volume fraction of WC was about 75%, but in the sprayed coating the volume fraction of the WC was reduced to about 20%. This is partly due to loss of W by oxidation, but chiefly due to dissolution of W into the metallic phase.     

TC4钛合金表面交流微弧氧化膜研究

在铝酸盐溶液中,采用交流微弧氧化方法在ＴＣ４钛合金表面制备出氧化物陶瓷膜．使用显微力学探针测定了膜的硬度和弹性模量分布,并探讨了微弧放电对氧化膜和钛合金基体组织、性能的影响．结果表明,钛合金表面经微弧氧化处理后,膜／金属界面附近钛合金基体显微组织保持不变,基体上也不存在硬化区．另外,来自溶液氧原子没有扩散进入未氧化的钛合金基体．氧化膜的显微硬度和弹性模量分布有相似的变化规律．从膜表层到膜内部,硬度和弹性模量逐渐增加．靠近钛／膜界面附近时达到最大值。分别为１３和２３０ＧＰａ膜不同深度处ＴｉＯ_２金红石和ＴｉＡｌ_２Ｏ_５尖晶石相的相对含量变化决定了硬度和弹性模量分布．     

绿色选择性吸收涂层的制备及其光学性能

采用阳极氧化后染色的方法,在铝板表面制备出绿色的太阳光谱选择性吸收膜层。重点研究了阳极氧化时间、电流密度和硫酸浓度等对涂层性能的影响,利用XRD、SEM、UV/VIS/NIR分光光度计、FTIR红外光谱仪等技术对铝板结构、形貌、光谱及红外反射特性等进行了测试表征。结果表明,当硫酸浓度为200g/l,电流密度为4A/dm2,阳极氧化时间为40min时,可以得到性能较好的膜层。彩色太阳能吸收涂层可与建筑物及其外部环境相协调,具有潜在的应用前景。     

溶胶-凝胶自蔓延燃烧法合成CoMn2O4尖晶石型陶瓷颜料用于制备墨绿色太阳能吸光涂层

采用溶胶-凝胶自蔓延燃烧法在400 ℃的低温条件下合成单相CoMn₂O₄尖晶石型陶瓷颜料。通过XRD、SEM及颜料的漫反射光谱系统地研究了煅烧温度对陶瓷颜料的晶型结构、晶粒尺寸、晶粒形貌、色值(L*、a、b)及热发射值(εT)的影响。最终,将合成的CoMn₂O₄尖晶石型陶瓷颜料与环氧改性的有机硅树脂、有机助剂混合,形成吸光涂料。采用操作简单、成本低廉、环境友好、容易实现大面积制备的涂料喷涂法将吸光涂料喷涂到金属铝基底上,制备出尖晶石型墨绿色陶瓷太阳能吸光涂层,其太阳能吸收值αs为0.785～0.815,热发射值为ε100为0.342～0.400。CoMn₂O₄尖晶石型陶瓷涂层为冷色太阳光吸收涂层,其呈现的墨绿色丰富了涂料涂层的颜色,能够满足太阳能户外建筑对彩色的要求。     

周期换向脉冲电沉积Zn-Ni合金镀层的结构与耐蚀特性

在硫酸盐型Zn-Ni合金镀液中,分别采用直流电沉积和周期换向脉冲电沉积方式制备Zn-Ni合金镀层。通过研究电源输出波形对Zn-Ni合金镀层微观形貌、XRD图谱特征以及耐蚀行为影响的规律,发现采用脉冲电沉积法制备的Zn-Ni合金镀层具有较好的微观形貌,镀层表面平整、结晶细致,镀层的自腐蚀电流小,耐蚀性好。综合分析研究结果表明,采用多参数周期换向脉冲电沉积法制备新型合金镀层具有广阔的应用前景。     

Theoretical Analysis of Spectral Selective Transmission Coatings for Solar Energy PV System

Spectral selective transmission coatings can adjust the spectrum of incident solar radiation to reduce the waste heat generation in solar cells and to improve solar photovoltaic conversion efficiency. The ideal spectral transmissivity of the coatings should match the spectral response of solar cells, which means the ideal spectral transmissivity should be equal to 1.0 in the range of the spectral response and 0 in the other spectrum. The reflection performance of the three kinds of spectral selective transmission coatings for silicon solar cells are designed and analyzed. The results indicated that the ZnS/Na₃AlF₆ coating systems have a wider reflected infrared (IR) region than the TiO₂/SiO₂ coating systems, but lower transmissivity in the wavelength range of 0.5 μm to 1.1 μm. Furthermore, an Nb₂O₃/SiO₂ coating system is proposed and optimized, which has 31 layers with a smaller total thickness of 2.675 μm. The radiative properties including reflectivity and transmissivity of spectral selective transmission coatings are investigated and theoretically analyzed.     

基于SCFNA法的FSS吸波材料设计及制备

目的 设计并制备一种与单元电导率匹配、电磁性能优异的柔性频率选择表面吸波材料。方法 首先选择空间限域强制组装法（SCFNA）制造具有优异导电性能的片材,再按圆形谐振单元裁剪并周期性排布在有机介质层内。完成频率选择表面（FSS）的制备后测试其电磁波性能,并与仿真模型优化的结果进行对比。结果 制备的柔性选择表面样件在频率为18～40GHz时吸收率达到96.22%以上。结论 使用空间限域强制组装法设计制备了导电单元,通过调整工艺参数实现对单元电导率的精准调控,成功制备出了一种在18～40 GHz频段下电磁性能优异的高柔性吸波体材料。     

碳化物超高温陶瓷太阳能选择性吸收涂层的研究进展

太阳能选择性吸收涂层是将太阳辐射选择性吸收转化成热能的材料.为更大限度地利用太阳能,高温太阳能选择性吸收涂层成为提高光热转化效率的关键部件.碳化物超高温陶瓷因具有良好的光学性能和高温稳定性而成为优选材料.目前,很多研究者已通过磁控溅射法、热喷涂法、溶胶凝胶法和激光涂覆法等方法制备了多种碳化物陶瓷基太阳能选择性吸收涂层,并且做了大量的工作来优化其性能.本文综述了碳化物陶瓷基太阳能选择性吸收涂层的研究进展,介绍了太阳能光谱选择性的要求及其选择性吸收的基本原理,总结了碳化物陶瓷基太阳能选择性吸收涂层的制备方法、材料、性能及其重要影响因素,最后展望了碳化物超高温陶瓷太阳能选择性吸收涂层的发展前景.     

Co-based Amorphous/Nanocrystalline Composite Coatings Deposited by Arc Ion Plating

Cobalt-based amorphous/nanocrystalline composite coatings have been grown by arc ion plating together with a specimen cooling system.With decreasing substrate temperature,the coatings undergo significant structure evolution.The degree of crystallization first decreases and subsequently increases as confirmed by X-ray diffraction.The cluster size first decreases and then remains constant as confirmed by transmission electron microscopy.The effect of substrate temperature on the evolution of the structure has been studied as a result of a competition between nucleation thermodynamics and kinetics of crystalline growth.With decreasing the substrate temperature,the microhardness and the critical load of the composite coatings firstly increased,and then remained almost constant.And the saturation magnetization revealed the opposite trend over the same range.The essence of these phenomena was ascribed to the microstructural variations caused by the decrease of the substrate temperature.     

中高温光谱选择性吸收涂层的研究进展

太阳能是极其丰富的可再生能源,近年来,研究人员不断努力开发高吸收低发射、耐高温、持久耐候的高性能光谱选择性吸收涂层。本文主要介绍国内外科研工作者在中温和高温光谱选择性吸收涂层方面的研究工作和最新成果,并对其高温热稳定性及失效机理进行了探讨。     

TiAlN/Cu Nanocomposite Coatings Deposited by Filtered Cathodic Arc Ion Plating

TiAlN/Cu nanocomposite coatings with Cu concentration of 0–1.4 at.% were deposited on the highspeed steel(HSS) substrates by filtered cathodic arc ion plating technique.The chemical composition,microstructure,morphology,adhesion strength,mechanical and tribological properties of the TiAlN/Cu coatings were characterized and analyzed.The results reveal that the coating structure and properties depend on not only the Cu concentration,but also the deposition condition.The addition of Cu significantly decreases the grain size and weakens the texture in the TiAlN/Cu coatings.With increasing the Cu concentration,the coating hardness decreases slightly from 30.7 GPa of the pure TiAlN coating to 28.5 GPa of the TiAlN/Cu coating with 1.4 at.% Cu.All the TiAlN/Cu coatings present sufficient adhesion strength.In addition,the existing state of additive Cu in the TiAlN/Cu coatings is also investigated.     

Wear Resistance of TiN_x/CF_y Coatings Deposited by RF Magnetron Co-Sputtering

TiN_x/CF_y composite coatings were prepared by RF magnetron co-sputtering using twin cylindrical tube targets with Ar and N_2 mixtures.The composition of the coatings deposited at various positions was analyzed by X-ray photoelectron spectroscopy(XPS) and Rutherford back-scattering spectrometry(RBS).The results revealed that the composition of the deposited coatings has a wide range of TiN_x and CF_y contents at different deposition positions,which leads to different structures and performances.The hardness of the composite coatings increases from 32 to 1603 HV with increasing the TiN_x concentration.The static contact angle of water ranges from 20° to 102° and decreases upon the incorporation of more TiN_x into the CF_y polymer.The presence of the CF_y groups enhances the contact angle between the coating and the solutions dropped onto it,which could effectively protect the coating from corrosion and improve the wear resistance properties in high relative humidity(RH).The brittleness of the coatings decreases due to the softness of the CF_y component,which can bear most of the load and result in less probability of crack formation.XPS results demonstrate the existence of a Ti-(C N) chemical bond in the composite coatings,which improves the wear resistance of the coatings.It is indicated that the wear resistance of the TiN_x/CF_y coatings is independent of the hardness.However,these properties depend on the uniform structure and the existence of chemical bonding between the TiN_x and CF_y phases.Moreover,a specific ratio between the soft CF_y phase and the hard TiN_x phase can produce coatings with good wear resistance.     

Ni-P/Ni-Mo-P镀层耐腐蚀性研究

通过在镀液中加入Na2MoO4的化学沉积法对酸性Ni-Mo-P/Ni-P双层化学镀工艺进行了研究。通过试验，确定了用连续施镀法制备此多元合金镀层的工艺。测定了镀层的性能，特别是对其耐腐蚀性能进行了重点研究。结果表明，镀层的成分及结构对其性能有关键的影响，双层镀镀层性能优于Ni-P单层镀镀层性能。     

多弧离子镀（Ti,W）xN合涂层组织与性能

采用Ti/W复合靶用多弧离子镀技术沉积了（Ti,W)xN合金涂层,并对该涂层的组织与性能进行了研究。结果表明,涂层组织致密,孔隙率极低,主要结构为（Ti,W)2n,并具有较高的显微硬度和抗氧化性。在沉积过程中存在着多元合金涂层与复合靶的成分离析现象,这与靶材的结构有关。