织物用水性多波段伪装印花涂料的研究与应用

目的 制备水性多波段伪装印花涂料及可见光/近红外/热红外多波段伪装织物.方法 将印花粘合剂、增稠剂、红外低发射率颜料、近红外高反射颜料、着色颜料、分散剂等制备咸水性多波段伪装印花涂料.采用圆网涂料印花工艺,将水性可见光/近红外/热红外多波段伪装印花涂料印染在涤棉混纺织物上,得到了四色可见光/近红外/热红外多波段伪装印花织物.通过环境扫描电镜、分光式测色仪、分光光度计、双波段发射率测量仪、红外热像仪等测试手段对印花织物的形貌、伪装性能、理化性能进行了表征.结果 印花涂层均匀附着在涤棉混纺织物纤维表面,印花织物的可见光迷彩颜色与环境背景相似,近红外光谱反射特性在0.4～1.2 μm范围内与背景基本上实现了同色同谱,在红外成像下形成有效梯度分割,且与背景有较好的融合效果.结论 制备的印花涤棉混纺织物具有可见光/近红外/热红外兼容伪装性能,各项性能指标达到了实用要求.     

冷颜料在红外隐身涂料中的应用

目的通过冷颜料降低目标的表面温度,起到红外隐身的作用。方法采用XRD衍射仪和紫外/可见光/近红外分光光度计等,分析颜料的相结构及近红外光谱特性。采用红外辐射率测量仪、紫外/可见光/近红外分光光度计和红外灯模拟太阳光照射,分析涂层的红外发射率及反射隔热性能。结果与炭黑颜料相比,铁铬黑颜料的近红外平均反射率为57%,且反射光谱与叶绿素基本一致;当填料质量分数为10%时,铁铬黑涂层的近红外反射率最大,平均反射率为39.2%,红外发射率为0.91;20%(质量分数)炭黑涂层和10%(质量分数)铁铬黑涂层相比,铁铬黑涂层的反射隔热效果明显,其平衡温度较普通炭黑涂层低8.8℃。结论红外隐身材料应考虑颜料对涂层红外发射率的影响,在满足涂层颜色的条件下尽量控制颜料的添加量,实际应用中以颜料添加10%(质量分数)为宜,在满足涂层反射隔热要求的同时,保证了涂层的红外发射率。     

石墨烯对聚氨酯/Al复合涂层光泽度及红外发射率性能的影响

目的在不明显升高聚氨酯(PU)/Al复合涂层红外发射率的前提下,明显降低涂层的光泽度,获得低光泽与低发射率兼容的功能涂层。方法采用石墨烯改性PU/Al复合涂层,系统研究石墨烯改性对涂层的微结构、光泽度、红外发射率及力学性能的影响规律,并对其成因进行分析探讨。结果当石墨烯添加量(占Al粉质量的百分比)小于6%时,石墨烯改性可明显降低涂层的光泽度,且对涂层发射率的影响不明显。当石墨烯添加量为4%时,可使涂层同时具备低光泽与低发射率性能,其值分别为11.0和0.245。涂层的力学性能对石墨烯改性并不敏感,改性前后涂层的硬度、附着力和耐冲击强度分别可达到3H,1级和50kg·cm。结论石墨烯改性可明显降低PU/Al复合涂层的光泽度。当石墨烯添加量合适时,可使涂层同时具备低光泽与低发射率性能,从而实现涂层的红外与可见光兼容隐身。     

8～14μm波段低发射率涂层材料的制备及性能研究

目的为满足市场对低发射率涂层的需要,制备了低发射率涂层材料,并讨论填料和基体树脂对其红外发射率的影响。方法以325、500、800、1000、1200、1500目铝粉为填料,丙烯酸树脂(AR)、环氧树脂(ER)和聚氨酯树脂(PR)为基体树脂,制备了低发射率涂层,分别从基体树脂种类、黏度、铝粉粒径及含量四个方面对涂层红外发射率进行了研究。结果 PR涂层在8~14μm波段的红外发射率最低,PR为低发射率涂层用基体树脂的最佳选择。涂层红外发射率随着基体树脂黏度的增大逐渐降低,并且变化趋势接近于线性。在研究范围内,铝粉的最佳粒径为325目,且涂层红外发射率随铝粉含量的增加而降低。结论制备的低发射率涂层的红外发射率低,而且环保。     

铜铬黑涂层的制备及其红外辐射性能

采用溶胶-凝胶法合成了铜铬黑(CuCr_2O_4)粉体,并以其为基料利用喷涂法在Q235钢表面制备了红外辐射涂层。研究表明,CuCr_2O_4粉体具有良好的高温稳定性,并在近红外波段具有良好的红外吸收性能,吸收率达到0.91。通过X射线衍射仪、紫外-可见-近红外分光光度计和IR-2双波段发射率测试仪对CuCr_2O_4涂层的物相组成及红外辐射性能进行了分析,并考察了涂层的抗热震性能和红外辐射加热性能。结果表明,CuCr_2O_4涂层在3~5μm波段具有良好红外辐射性能,发射率达0.86,此外该涂层还具有良好的抗热震性能和显著的加热节能效果。     

超疏水低红外发射率复合涂层的制备及性能表征

目的制备得到具有超疏水特性的低红外发射率涂层。方法以纳米SiO_2为微纳结构改性剂,聚二甲基硅氧烷(PDMS)为树脂基体,Al粉为功能颜料,采用刮涂法制备得到了多种类型的改性和非改性PDMS/Al复合涂层。分析探讨了PDMS和Al粉配比、纳米SiO_2添加量及表面微纳结构层对涂层性能的影响规律及成因。结果 PDMS和Al粉配比对涂层发射率和光泽度影响明显,当PDMS和Al粉配比为6∶4时,涂层的发射率和光泽度可分别低至0.265和10.3,涂层的水接触角可达到109.5°,要明显高于传统树脂基低发射率涂层。添加纳米SiO_2可使涂层的粗糙度上升明显,从而使涂层的疏水性显著增强。当纳米SiO_2质量分数为8%时,涂层的水接触角可增大到130°,涂层的发射率和光泽度仍可低至0.330和9.8。PDMS/SiO_2微纳结构层可在PDMS/Al复合涂层表面形成明显的乳突状微纳结构,从而使涂层实现超疏水特性。当PDMS和纳米SiO_2配比为7∶3时,改性后的涂层水接触角可高达156°,同时具有相对较低的发射率(0.661)和极低的光泽度(2.1)。结论在PDMS/Al复合涂层表面构筑一定厚度的微纳结构层,可实现该涂层超疏水、低发射率和低光泽的兼容。     

炭/炭复合材料表面SiC/ZrSiO4-SiO2复合涂层的抗氧化性能与红外发射特性研究

为提高炭/炭(C/C)复合材料的高温抗氧化性能并降低其红外发射率,采用包埋–刷涂法在其表面制备了SiC/ZrSiO_4-SiO_2复合涂层。借助XRD、SEM等表征分析了涂层的成分与微观结构,并研究了SiC/ZrSiO_4-SiO_2复合涂层包覆C/C复合材料在1500℃动态空气条件下的抗氧化性能,以及在90和500℃下的红外发射率。结果表明:由疏松结构SiC内涂层和镶嵌结构ZrSiO_4-SiO_2外涂层组成的SiC/ZrSiO_4-SiO_2复合涂层具有优异的抗氧化性能,在1500℃流动空气(0.6 L/min)等温氧化条件下氧化50 h后试样的氧化失重率仅为0.03%。在C/C复合材料表面制备SiC/ZrSiO_4-SiO_2复合涂层后其红外发射率明显降低,并随温度升高而越低。复合涂层包覆试样在90℃时3~5μm和8~14μm波段的平均红外发射率分别为0.55和0.66;在500℃时3~5μm和8~14μm波段的平均红外发射率分别为0.48和0.62。SiC/ZrSiO_4-SiO_2复合涂层包覆C/C复合材料可作为优良的低红外发射率高温热结构材料应用于航空航天领域。     

碳基陶瓷隔热瓦表面高发射耐烧蚀抗氧化涂层的制备及性能

本实验采用大气等离子喷涂技术在碳基陶瓷隔热瓦ZrB2-SiC-玻璃内涂层表面制备镍铬尖晶石高发射涂层以提高其抗氧化耐烧蚀性能。利用XRD和SEM对粉体和涂层的相结构和微观形貌进行分析,采用氧-乙炔火焰对涂层进行烧蚀试验。结果表明,在Cr2O3:NiO摩尔比为1:1.2,1200℃固相反应2h后,可以得到物相较纯的NiCr2O4尖晶石粉体;Cr2O3:NiO摩尔比不变,掺入质量分数15%TiO2、25%MnO2,1200℃固相反应2h可以得到复杂的混合尖晶石粉体。纯NiCr2O4涂层及掺杂NiCr2O4涂层的发射率在1~22μm波段分别达到0.955和0.954。喷涂后纯NiCr2O4发生了轻微的分解,发射率有所降低,而掺杂NiCr2O4相结构稳定,不易分解,发射率稳定。氧-乙炔火焰烧蚀考核结果表明,当火焰温度高于2000℃时,掺杂NiCr2O4涂层表面温度比纯NiCr2O4涂层降低了240℃,其红外辐射性能优于纯NiCr2O4涂层。掺杂NiCr2O4涂层能耐受大于2000℃/300 s烧蚀考核,具有良好的高发射耐烧蚀性能。     

等离子喷涂 NiCoCrAlY / Al2 O3 高温固体润滑耐磨涂层的抗氧化性能研究

目的研究等离子喷涂NiCoCrAlY/Al2O3高温固体润滑耐磨涂层在850℃时的高温抗氧化性能和抗氧化机理。方法采用喷雾造粒、化工冶金包覆技术制备NiCoCrAlY/Al2O3复合粉体,并采用等离子喷涂技术在45#钢表面制备NiCoCrAlY/Al2O3复合涂层。采用SEM和XRD研究粉体和涂层的显微结构和物相组成,并采用马弗炉研究复合涂层在850℃的恒温氧化动力学曲线,通过研究氧化96 h以后涂层表面的组织形貌,探讨NiCoCrAlY/Al2O3复合涂层的抗氧化机理。结果 NiCoCrAlY合金层均匀致密地包覆在Al2O3颗粒的表面,包覆层厚度约为3~5μm。复合粉体的主要组成为Al2O3相和NiCoCrAlY合金相,没有其他杂质相的存在。等离子喷涂NiCoCrAlY/Al2O3复合涂层氧化动力学曲线分为大斜率直线、抛物线和系数几乎为0的抛物线等3个阶段。氧化96 h以后,涂层的氧化质量增量为4.9 mg/cm2左右,表面形成了一层连续的氧化物保护膜,经EDX分析,氧化膜层主要由Al,O,Cr和Ni组成。结论等离子喷涂NiCoCrAlY/Al2O3复合涂层具有良好的高温抗氧化性能,涂层中Ni,Cr,Al的氧化以及硬质相Al2O3的加入是涂层抗氧化的主要原因。     

高紫外反射ZnO/SiO2复合粉体制备及其热控涂层性能研究

目的 以ZnO/SiO2复合粉体为填料,开展新型热控涂层制备方法研究,提高传统白色热控涂层的紫外反射率, 研制出具有太阳全光谱高反射性能的热控涂层。方法 以硫酸锌和硅酸钠为原料,采用常温化学合成与高温热处理相结合的方法制备ZnO/SiO2复合粉体,通过X射线衍射仪、扫描电子显微镜及紫外可见分光光度计等仪器,对复合粉体的微观结构及光学性能进行表征。然后以ZnO/SiO2复合粉体为填料,以无机硅酸钾为粘结剂,制备了ZnO/SiO2热控涂料,通过不同颜基比和厚度的优化,得到了太阳全光谱(200~ 2600 nm)高反射白色热控涂层的制备方法。结果 研制的ZnO/SiO2复合粉体在紫外波段的反射率均大于88%,与传统ZnO粉体相比具有明显提升。当以无机硅酸钾为粘结剂、颜基比为2:1、喷涂厚度为100~140 μm时,所制备涂层在太阳全光谱呈现高反射特性,此时涂层的太阳吸收比为0.12,红外发射率为0.92。结论 ZnO/SiO2热控涂层具有优异的热控性能,与传统白色热控涂层相比具有更低的吸收比,同时在太阳全光谱具有高反射特性,可以满足新一代大功率卫星长寿命和高效散热的技术需求。     

不同发射率红外隐身涂层在典型背景中的伪装效率研究

通过对发射率F为0．42～0．95的迷彩隐身涂层在典型背景中的红外温度和红外热像图的测试分析,总结出不同红外发射率隐身涂层在周日里与典型背景的融合程度,计算了各发射率隐身涂层的伪装效率。对红外隐身涂层的发射率梯度设计和不同发射率红外斑块在目标表面的分布提出了合理化建议。     

Experimental investigation of emissivity of aluminum alloys and temperature determination using multispectral radiation thermometry (MRT) algorithms

Experiments were performed to measure the emissivity spectra for aluminum (Al) surfaces that are subject to variations in alloy, temperature, heating time, and surface finish. The linear emissivity model (LEM) and log-linear emissivity (LLE) model were tested against thermocouple measurements to explore the accuracy of these models at inferring surface temperature. The data show emissivity decreases with increasing wavelength for λ<3.5 μm, but the trend is reversed at higher wavelengths. Except for AL 1100 (commercially pure Al), the emissivity of all alloys tested decreased 600–700 K and increased 700–800 K. The increased emissivity at 800 K was closely associated with a discoloration of surfaces from light gray into black. Surface roughness produced a 2- to 3-fold increase in emissivity compared with polished surfaces. Overall, the third-order LEM model showed the best overall accuracy for different alloys, temperatures, and surface roughness. Nonetheless, this study points to a need for more accurate models that could handle the diverse operating environment of Al processing plants.     

Emissivity of La1-xSrxMnO3/acrylic Resin Thermal Control Coating

Thermal control coatings were fabricated by mixing of La1-xSrxMnO3(LSMO)powder and acrylic resin and brushed on Al alloy substrate.The powders of La0.7Sr0.3MnO3 and La0.8Sr0.2MnO3 were prepared using sol-gel method.XRD results reveal the phase structure of LSMO powders are perovskite.The transition temperature from metal to insulator of La0.7Sr0.3MnO3 and La0.8Sr0.2MnO3 are 300 and 275 K,respectively.The emissivity evolution with temperature of the coatings was measured.For La0.7Sr0.3MnO3/acrylic resin coating,the emissivity increases from 0.56 to 0.88,and for La0.7Sr0.3MnO3/acrylic resin coating from 0.50 to 0.90.     

Infrared emissivity and corrosion-resistant property of maleic anhydride grafted ethylene-propylene-diene terpolymer (EPDM-g-MAH)/Cu coatings

Maleic anhydride grafted ethylene-propylene-diene terpolymer (EPDM-g-MAH) was prepared by grafting copolymerization method. Composite coatings with varied infrared emissivity were obtained by using copper (Cu) powder as inorganic pigments, either EPDM or EPDM-g-MAH as organic adhesive. The influences of the content of Cu powder and adhesive kinds on the infrared emissivity of the composite coatings were investigated. The as-prepared coatings were characterized by FTIR spectroscopy, infrared emissometer and SEM. The corrosion-resistant property of the coatings in aqueous 3.5 wt.% NaCl was assessed by the potentiodynamic polarization technique and electrochemical impedance spectroscopy (EIS). The results have shown that the interfacial interaction between EPDM and Cu is improved due to the MAH grafting on EPDM, benefiting from the compatibility of EPDM with Cu and the low porosity of EPDM/Cu coatings, which leads to the lower infrared emissivity and better corrosion-resistant property of the coatings.     

Application of low-emissivity Pt layer on Ni alloy to high temperature

Platinum films were sputter-deposited on two groups of nickel alloy substrates, in which the first group was the samples with rough surface, and the other group with polished surface. The platinum thin-films were applied to serve as the low-emissivity layers to reflect thermal radiation. Then, the platinum-coated samples were heated in air at 600 ℃ for 200~h to explore the effect of high-temperature environment on the emissivity of coated platinum film. After annealing, the average IR emissivity (at the wavelength of 3-14 μm) of the platinum film was only about 0.1 for polished sample and 0.45 for rough sample. The diffusion between platinum and the nickel-alloy elements at
600 ℃  had been also discussed.     

Preparation,characterization and infrared emissivity properties of polymer derived coating formed on 304 steel

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.     

不同包裹工艺对SiC抗氧化和红外性能的影响

分别以硅溶胶、硅酸和硅微粉对SiC粉进行包裹实验,得到的样品用双波段红外发射率测量仪测试其常温下8~14μm波段的发射率,用X射线衍射仪测试其物相组成,并测试样品1200℃保温4h的氧化增重率。研究表明,硅溶胶、硅酸和硅微粉的引入均提高了SiC的抗氧化性能,其中硅溶胶和硅微粉效果较好;同时,硅溶胶、硅酸和硅微粉的引入均可提高样品的红外发射率,其中以硅酸引入效果为最好。     

KS-B高吸收高发射率无机热控涂层低轨环境效应

目的 研究低轨环境对KS-B高吸收高发射无机热控涂层(简称KS-B涂层)性能的影响。方法 对KS-B涂层分别进行总剂量为3.9×10²² atoms/cm²的原子氧辐照、剂量为5000 ESH的真空-紫外辐照、总注量为9.30×10¹¹ p/cm²的真空-质子及总注量为1.108×10¹⁴ e/cm²的真空-电子综合辐照试验,分析空间模拟辐照环境中KS-B涂层太阳吸收比(αS)、半球发射率(εH)、表面形貌、表面组分含量、质量损失率等性能的变化规律,研究KS-B涂层的耐空间环境稳定性。结果 原子氧暴露后,KS-B涂层太阳吸收比增加0.003,半球发射率增加0.004;原子氧辐照后,KS-B涂层表面形貌出现了一定程度的糙化,表面Si、O元素含量下降。初始暴露时,KS-B涂层质量损失率逐渐提高,最终质量损失率为0.96%。真空-紫外辐照后,KS-B涂层太阳吸收比增加0.003,半球发射率无变化。真空-质子及真空-电子辐照前后,KS-B涂层太阳吸收比增加0.001,半球发射率无变化。结论 经历原子氧、真空-紫外、真空-质子及真空-电子模拟辐照后,KS-B涂层的太阳吸收比及半球发射率变化较小,具有较好的耐空间辐照性能,可以满足空间站等低轨航天器的长寿命服役需求。     

Corrosion and mechanical properties of epoxy-polyurethane/bronze composite coatings with low infrared emissivity

Low infrared emissivity coatings were prepared by using epoxy-polyurethane (EPU) and bronze as adhesives and fillers, respectively. Due to the increasing electrical conductivity with increasing bronze content, the infrared emissivity is decreasing obviously. Mechanical properties of EPU/bronze composite coatings were studied by using adhesion test and impact strength test. We found that EPU/bronze composite coating had good adherence and impact strength at bronze content below 50 wt.%, and then the mechanical properties decreased in the bronze content range from 50 wt.% to 60 wt.%. Moreover, the composite coatings were tested for the corrosion behavior with potentiodynamic polarization. Corrosion test results showed that the low emissivity EPU/bronze composite coatings exhibited favorable corrosion resistance. By comparing EPU/bronze, PU/Cu, (ball-milled Ag-Cu)/PU and PU/Al coatings, the EPU/bronze coatings with 40 wt.% bronze have the best adherence, low infrared emissivity and good corrosion resistance.     

K424合金镀金膜后红外发射率变化

研究了表面镀金膜的K424合金在热处理前后红外发射率的变化和变化机制.XRD分析结果表明,在热处理后基体金属元素扩散到金膜中,并主要形成了Cr在Au中的固溶体-Au0.7Cr0.3.EDXS分析表明,粗糙表面镀金膜的试样在热处理后,表面主要形成了基体金属元素的氧化物;而抛光表面镀金膜的试样,其表面仍为金膜.通过SR5000光谱辐射计量仪测量合金的红外发射率,结果表明,合金的表面状态和热处理对红外发射率均有较大影响.