Microstructure and performance analysis of organic coating under high temperature and high CO<Subscript>2</Subscript> partial pressure

To evaluate the property of the organic coatings in oil and gas plants, the aging process was studied in high temperature and high CO₂ partial pressure environment. Correlations were developed between the macroscopic properties and microstructure of the organic coatings. The surface appearance, mechanical properties, and permeability of the organic coatings were measured. Furthermore, the crystal structure of the organic coatings was investigated through synchrotron radiation grazing incidence X-ray diffraction (GIXRD) on the BL14B1 beam line in Shanghai Synchrotron Radiation Facility. Combined with the Fourier transform infrared spectroscopy, the molecular structure of the organic coatings was investigated. The experimental results indicate that the thickness variation and weight loss of the organic coatings increase with the immersion time, and the penetration resistance of the coating obviously decreases as the temperature rises. Moreover, the degradation of the organic coatings with immersion time in high temperature and high CO₂ partial pressure environment is caused by the amorphization of the organic coatings as the groups and bonds of the organic coatings were not damaged.     

High temperature behaviors of high velocity arc sprayed Fe-Al/Cr3C2 composite coatings

Fe-Al/Cr3C2 composite coatings were manufactured using high velocity arc spraying （HVAS） technology. The high temperature erosion, wear and corrosion resistance of the coatings were investigated. The coating properties such as bonding strength, porosity, hardness as well as microstructures were characterized. The results show that the coatings have relatively high heat tremble bond strength, hardness, and typical layer-shaped coatings＇ microstructures. With the rise of temperature, the coating erosion resistance increases too; the impingement angel does effects on erosion properties, and the erosion mechanism changes from ductile to brittle behaviors at 450℃. The coatings have good room temperature wear resistance and relatively good high temperature resistance. The wear mechanism of the coatings is peeling wear behavior. The coatings have excellent high temperature corrosion resistance because of the produce of oxides during corrosion.     

混合炸药造型粉的超临界流体反溶剂过程制备

将超临界流体反溶剂(Supercritical Fluid Anti-solvent,SAS)过程用于炸药表面包覆.采用氟橡胶F2602为包覆材料,乙酸乙酯为共溶剂,与炸药形成悬浮液,超临界CO2为反溶剂.研究了体系温度、压力和进气速率对炸药包覆效果的影响.经过对包覆后样品的性能测定和SEM分析,结果表明:体系温度是影响包覆效果的最关键的工艺参数,压力和进气速率也有一定影响,通过合理调节以上工艺参数可以获得较佳的包覆效果.     

Corrosion protection of AM50 magnesium alloy by Nafion/DMSO organic coatings

The effectiveness of the corrosion protection of Nafion/Dimethysulfoxid （DMSO） organic coatings for AM50 magnesium alloy prepared by simple immersion and heat treatment was investigated. Its corrosion resistance and morphologies of the Nafion/DMSO organic coatings were studied by electrochemical corrosion testing and optical microscopy. The results show that Nafion/DMSO organic coatings can improve the corrosion resistance of AM50 magnesium alloy effectively. Also, the corrosion resistance increases with the surface density of the organic coatings.     

高酸值松香的加氢工艺研究及产物性能探讨

高酸值松香在高温高压条件下进行加氢反应,使分子内碳-碳双键饱和,得到稳定的工业化产品.以Pd/C为催化剂,研究了不同加氢工艺条件对产物性能的影响,得到最佳加氢反应条件:加氢反应压力5 MPa,反应温度200℃,反应时间2 h,催化剂用量0.3%.采用红外光谱法对加氢前后高酸值松香的结构进行了表征,并通过氧化性实验等方法对加氢效果进行评价.结果表明:在此条件下加氢,产物碳碳双键含量减少,其综合性能特别是高温耐氧化性得到了显著提高.     

Structure and Oxidation Behavior of a Plasma Sprayed Yttrium Silicates Coated SiC-C/C with a Glass Outer Sealant from 1 573K to 1 873K

Different compositions of yttrium silicates coatings were deposited on SiC-C/C by plasma spraying and an outer borosilicate glass was applied on the yttrium silicates coatings surfaces.The structure of the multi-layer coatings was characterized by XRD and SEM analyses.High temperature oxidation behavior of the multi-layer coatings coated C/C composites was investigated.Results show that SiC/2SiO_2Y_2O_3/I.5SiO_2 Y_2O_3/SiO_2 Y_2O_3/glass multi-layer coating has better high temperature oxidation resistance,protecting carbon/ carbon composites from oxidation at 1 773 K in air for 164 h with the weight loss of 1.65%.The oxidation weight loss of the coated C/C with time accorded with parabolic rule in the temperature range 1 573 K-1 873 K; and the corresponding oxidation activation energy of the coated carbon/carbon composites is 132.2 kJ/mol.     

Structure and oxidation behavior of a plasma sprayed yttrium silicates coated SiC-C/C with a glass outer sealant from 1 573K to 1 873K

Different compositions of yttrium silicates coatings were deposited on SiC-C/C by plasma spraying and an outer borosilicate glass was applied on the yttrium silicates coatings surfaces. The structure of the multi-layer coatings was characterized by XRD and SEM analyses. High temperature oxidation behavior of the multi-layer coatings coated C/C composites was investigated. Results show that SiC/2SiO2 Y2O3/1.5SiO2 Y203/ SiO2 Y2O3/glass multi-layer coating has better high temperature oxidation resistance, protecting carbon/ carbon composites from oxidation at 1 773 K in air for 164 h with the weight loss of 1.65%. The oxidation weight loss of the coated C/C with time accorded with parabolic rule in the temperature range 1 573 K-1 873 K; and the corresponding oxidation activation energy of the coated carbon/carbon composites is 132.2 kJ/mol.     

Erosion-Corrosion Behaviors of High Velocity Arc Sprayed Fe-Al/Cr3 C2 Coating

1 IntroductionArc Spraying (AS) is a technique that utilizes anelectric arc as the heat source to melt wires into droplets ,which are subsequentlysprayed ontosubstrates bytheflowof compressed air . High Velocity Arc Spraying (HVAS)technology was developed on the basis of AS. Aspecialtube designed according to the principle of aerodynamicswas mounted at the exit of compressed air .Thenthe hightemperature fuel air or compressed air was accelerated bythe tube .Hence ,a higher velocityand be…     

电刷镀Ni - P合金镀层的高温摩擦磨损性能

对电刷镀Ni - P合金镀层的高温摩擦磨损性能进行了研究.实验结果表明,在20CrMo钢基体上,电刷镀Ni - P合金镀层能有效降低试样在高温(450 ℃)下的摩擦因数,减小高温磨损量.其中,12 min电刷镀试样在高温摩擦测试前80 min内,摩擦因数基本维持在平均值约0.30,仅为20CrMo钢基体(0.60)的50%;80～120 min因镀层局部被磨损穿透,其摩擦因数缓慢增长;120 min后,基本维持在平均值约0.50,测试完成后质量磨损量为同等测试条件下20CrMo钢基体的19.99%;24 min电刷镀试样在450℃下摩擦测试180 min的整个过程中,摩擦因数均较稳定,平均值为0.30,高温摩擦磨损测试后的质量磨损量仅为20CrMo钢基体的6.36%.     

有机合成纤维对隧道管片混凝土经高温后性能的影响

基于高温传感器建立了高温自动采集系统,对火灾高温环境下混凝土内部温度进行了监测,对盾构法隧道管片有应用前景的有机纤维混凝土高温后的性能进行了试验研究.试验结果表明:火灾过程中混凝土构件从内到外存在很明显的温度梯度,掺入有机合成纤维能明显降低温度梯度引起的混凝土开裂、爆裂、剥落现象;聚丙烯纤维分解温度高于纤维素纤维和聚乙烯醇纤维,在弯拉强度、断裂能、断裂韧性及残余强度方面聚丙烯纤维混凝土均优于聚乙烯醇纤维混凝土和纤维素纤维混凝土,更适合用于提高隧道管片混凝土在火灾高温环境下的抗爆裂性能.     

环氧涂层/镀锌板电极系统腐蚀电化学行为

利用EIS研究环氧型有机涂层的腐蚀电化学行为。在浸泡初期阻抗谱是一个时间常数的单容抗弧,阻抗值基本不变,此时漆膜能够阻止介质渗入。在浸泡中期阻抗值随时间逐渐增大,原因为镀锌钢板表面预处理层的铬酸盐自修复作用以及铬酸盐转化膜溶解物和腐蚀产物沉积堵塞漆膜微孔隙,阻止介质渗入到达镀锌钢板表面,导致阻抗值变大。后期,预处理膜完全溶解破坏,金属基体腐蚀反应加快,阻抗值变小.     

用鹅油直接制取CO_2缓蚀剂

讨论了以鹅油为原料直接制取CO_2腐蚀防护的缓蚀剂。利用正交试验对反应中主要原料的摩尔比、反应温度、反应时间、反应压力的影响进行了考查。通过测定合成产物在CO_2腐蚀环境中的缓蚀性能。确定了以鹅油为原料直接制取CO_2缓蚀剂的工艺条件。     

High Purity Hydrogen Production by Metal Hydride System:A Parametric Study Based on the Lumped Parameter Model

The simulation of hydrogen purification in a mixture gas of hydrogen/carbon dioxide (H2/CO2) by metal hydride system was reported.The lumped parameter model was developed and validated.The validated model was implemented on the software Matlab/Simulink to simulate the present investigation.The simulation results demonstrate that the purification efficiency depends on the external pressure and the venting time.An increase in the external pressure and enough venting time makes it possible to effectively remove the impurities from the tank during the venting process and allows to desorb pure hydrogen.The impurities are partially removed from the tank for low external pressure and venting time during the venting process and the desorbed hydrogen is contaminated.Other parameters such as the overall heat transfer coefficient,solid material mass,supply pressure,and the ambient temperature influence the purification system in terms of the hydrogen recovery rate.An increase in the overall heat transfer coefficient,solid material mass,and supply pressure improves the hydrogen recovery rate while a decrease in the ambient temperature enhances the recovery rate.     

VMS有机-无机杂化膜的制备及其防腐性能研究

以乙烯基三甲氧基硅烷（VMS）为前驱体,采用浸涂法在LY12铝合金表面制备了有机一无机杂化防腐保护膜．分别考察了涂膜次数、固化剂用量和溶剂用量对膜层防腐性能的影响,成膜的最佳工艺条件为：固化剂过氧化苯甲酰（BPO）的加入量为凝胶量的2％（质量分数）;凝胶质量与溶剂质量的比为0．17;涂膜四次．利用动电位极化曲线、盐雾实验和盐水浸泡实验评价了膜层的耐腐蚀性能．结果表明,乙烯基三甲氧基硅烷（VMS）膜层可使腐蚀电流减小到原来的1／300左右,同时也使得试片耐长久腐蚀的能力显著增强．     

高压有机片式钽电容器高温可靠性研究

高压有机固体电解质片式钽电容器的高温特性是限制此类电容器广泛应用的瓶颈,目前国际上普遍采用105℃的温度上限,而不能满足125℃环境下的特殊使用要求。该文通过对电介质进行"屏蔽"和预处理,对有机固体电解质进行后处理和包封层改善,高压有机电解质片式钽电容器的高温特性得到明显改善,能够安全通过105℃、2 000 h和125℃、2 000 h寿命试验。该研究结果将为有机固体电解质片式钽电容器在特殊环境下的应用提供必要的技术支撑。     

Thermal insulation and cooling properties of thermal barrier coatings of flame baffles

In order to study the thermal insulation and cooling properties of thermal barrier coatings of a flame baffle,several ZrO2 thermal barrier coatings with different thicknesses were prepared on the surfa...     

ZnO纳米薄膜在竹材表面的生长及防护性能

在低温溶液反应体系下,通过晶种形成和晶体生长两步法在竹材表面培育ZnO纳米结构薄膜,应用场发射环境扫描电镜(FESEM)、X射线衍射仪(XRD)和X射线能谱仪(EDAX)对薄膜形态和结构进行表征,重点研究种子液浸渍时间对纳米薄膜形态及竹材防霉和抗光变色性能的影响.研究结果表明,在生长时间一定的前提下,竹材在种子液中经过0.5 h、1 h和2 h的浸渍,其表面可形成壁厚为50～80 nm的网状结构薄膜,使竹材的防霉性能和光稳定性得到显著改良;当种子液浸渍时间增加到4 h,网状结构薄膜则被大量直径约700 nm的ZnO圆片所覆盖,虽然此时竹材的防光变色性能保持不变,但防霉性能下降,表明纳米网状结构对于充分发挥ZnO防护性能起到重要作用.     

铸造用CO2硬化碱性酚醛树脂的试验研究

铸造业中广泛使用的树脂材料基本上都是一些有毒、污染环境的，因此开发出高质、高效、节能、环保的新型粘结剂是当前铸造绿色集约化发展的迫切需要.针对此粘结剂的特点，以抗压强度为主要考察目标，通过对其碱加入量、硼砂加入量和硅烷加入量进行正交试验，得出优化结果，并对树脂砂的可使用时间、发气性、溃散性和树脂加入量等工艺性能进行了试验研究.试验表明，此粘结剂制得的树脂砂具有良好的工艺性能，吹CO₂气体硬化后，可获得较高的初强度和终强度.     

A photosensitive copolymer for UV-curable electrodeposition coatings

A series of photosensitive random copolymers (UPDHES) were prepared by introducing acrylate groups onto the side chain of the copolymer backbone of N, N-domethyl amimethyl methacrylate (DMAEMA), 2-hydroxypropyl acrylate (HEA), 2-ethylhexyl acrylate (EHA), and styrene (St) (PDHES). The molecular structure of UPDHES was characterized by FTIR, 1HNMR and GPC. The photopolymerization kinetics of UPDHES with different C=C content was investigated using real time FTIR in which it was found that the UPDHES system had notable photosensitivity. The effect of C=C content on the properties of cured films were studied by evaluating various film properties such as thermal stability, glass transition temperature and tensile properties. The thermal degradation of cured films was investigated via thermogravimetric analysis/infrared spectrometry (TGA-IR). Thus a series of UV-curable electrodeposition coatings with good photosensitivity and mechanical properties were prepared from a low-cost photosensitive random copolymer.     

Effect of Deposition Time on Microstructures and Growth Behavior of ZrC Coatings Prepared by Low Pressure Chemical Vapor Deposition with the Br_2-Zr-C_3H_6-H_2-Ar System

ZrC coatings were deposited on graphite substrates by low pressure chemical vapor deposition(LPCVD) with the Br_2-Zr-C_3H_6-H_2-Ar system. The effects of deposition time on the microstructures and growth behavior of ZrC coatings were investigated. ZrC coating grew in an island-layer mode. The formation of coating was dominated by the nucleation of ZrC in the initial 20 minutes, and the rapid nucleation generated a fine-grained structure of ZrC coating. When the deposition time was over 30 min, the growth of coating was dominated by that of crystals, giving a column-arranged structure. Energy dispersive X-ray spectroscopy showed that the molar ratio of carbon to zirconium was near 1:1 in ZrC coating, and X-ray photoelectron spectroscopy showed that ZrC was the main phase in coatings, accompanied by about 2.5mol% ZrO_2 minor phase.