柔性基底Mo-Al2O3金属陶瓷薄膜性能及其应用

柔性Mo-Al2O3金属陶瓷复合膜以聚酰亚胺为基底,具有膜系结构简单、轻质、高效吸热以及热稳定性等优点,是一种新型吸热型热控薄膜材料,可应用于航天器热控器件。着重介绍了柔性Mo-Al2O3金属陶瓷复合膜的膜系结构设计,并对其在航天器中的应用前景进行了分析。     

薄膜热电偶瞬态温度传感器Al_2O_3绝缘膜制备工艺及性能表征

制备绝缘性能良好的Al2O3薄膜是研制薄膜热电偶瞬态温度传感器的关键技术之一。针对直流脉冲磁控溅射制备的Al2O3绝缘薄膜总是存在针孔等缺陷,提出了利用直流脉冲磁控溅射加射频偏压技术成功制备了薄膜热电偶瞬态温度测试传感器的Al2O3绝缘薄膜。通过台阶仪、高阻计、扫描电子显微镜和划痕试验仪对Al2O3绝缘膜的成膜厚度、绝缘性、表面形貌及膜基结合力进行了观测,结果表明,制备的Al2O3绝缘膜厚度可达2.4μm;其绝缘性可达2.6×109Ω;薄膜表面光滑,成膜均匀;Al∶O原子比近似为2∶3;与金属基体的结合力可达12N。提供了一种制备高致密、高绝缘性能Al2O3薄膜的简单有效的方法,为制备瞬态温度传感器提供了技术保障。     

高功率脉冲磁控溅射制备TiNx涂层研究

采用高功率复合脉冲磁控溅射技术(HPPMS)在316不锈钢、硬质合金基体上沉积了TiN薄膜,研究不同N2流量下TiNx膜层的沉积速率、硬度、晶体生长取向、摩擦磨损等性能,并在相同的平均靶电流下与直流磁控溅射制备的TiN薄膜对比.结果表明:HPPMS制备的膜层更加致密,在氩氮流量比为7.4∶1时膜层显微硬度达2470 HV,晶粒尺寸也明显小于直流磁控溅射制备的TiN,摩擦磨损性能也得到了改善.     

直流反应溅射沉积Al2O3薄膜及其在SS-AlN金属陶瓷太阳吸收涂层的应用

在沉积不锈钢-氮化铝(SS-AlN)金属陶瓷太阳吸收集热管的磁控溅射三靶镀膜机上,安装了UPS03反应溅射闭环控制单元,实现反应溅射Al2O3稳定反馈控制。采用国产直流电源在Al靶表面处于过渡态下,成功制备了吸收几乎为零的Al2O3薄膜。溅射功率在14kW时,反应溅射沉积Al2O3的靶电压波动可长时间稳定控制在±3 V范围内,沉积速率为5.4 nm/(min·kW),约为Al靶在无反应气体溅射下沉积Al薄膜速率的74%。采用Al2O3代替AlN作为减反射层,应用到SS-AlN太阳选择性吸收涂层中,进一步提高了复合膜的太阳光学性能,太阳吸收比由AlN作为减反射层的0.956提高到0.965,红外发射比不变,仍为0.044。     

镁合金微弧氧化/空气喷涂复合膜层的耐盐雾腐蚀性能

为了进一步提高AZ31B镁合金的耐腐蚀性,在Na2SiO3电解液体系中,通过微弧氧化直流脉冲电源在其表面制备了微弧氧化膜,再在微弧氧化膜层上喷涂纳米陶瓷涂料层.利用盐雾腐蚀试验研究了微弧氧/涂料复合膜层的耐腐蚀性,采用SEM、XRD等研究了复合膜的组成和结构.结果表明:复合膜层表面均匀,其耐腐蚀性明显高于微弧氧化膜层,...     

MAO层厚度对MAO/DLC复合膜层力学性能与摩擦学特性的影响

借助直流脉冲微弧氧化(MAO)电源,采用恒压模式在AZ80镁合金表面制备四种不同厚度MgO陶瓷层,并以此为基,采用离子束复合磁控溅射技术沉积类金刚石碳(DLC)膜,对比研究了四种膜层体系(MAO-1min/DLC、MAO-3min/DLC、MAO-5min/DLC及MAO-10min/DLC)的表面结构特征、力学性能以及摩擦学性能差异。结果表明:随MAO层厚度增加,复合膜层表面微孔的孔径增大,表面粗糙度增加,且表层DLC膜具有颗粒特征,表现为MAO-3min/DLC及MAO-10min/DLC复合膜层具有较高的纳米硬度和弹性模量,且在磨损过程中对应的摩擦系数与磨痕宽度较小,其抗磨损性能优异;各复合膜层体系在磨损过程中摩擦系数均有波动,产生高温氧化,磨痕表面形成了Fe的转移层;MAO层可提高基体对DLC膜的支撑强度,表层DLC膜对磨损界面具有的润滑作用是复合膜层改善镁基体抗磨损性能之原因所在。     

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。     

精密磨擦材料氧化铝/聚酰亚胺磨片的制备

采用一次成膜和程序升温法,制备了以聚酰亚胺为基底的氧化铝新型磨片(Al2O3/PI),可用于硬脆性机件表面的精加工和抛光.扫描电镜(SEM)显示,Al2O3/PI磨片为双层膜型,磨料层厚度约50μm,基底厚度约150 μm.差热分析(DSC/TGA)、拉伸强度和断裂伸长率测试表明显示,Al2O3/PI磨片的热分解温度大于500℃,并具有PI膜的高强度和良好的柔韧性.对磨片制备过程的主要影响因素及铜片的抛光效果进行了讨论.     

磁控溅射技术新进展及应用

主要简介了磁控溅射技术的基本原理、基本装置、近年来出现的新技术(多靶磁控溅射技术、磁场扫描法、非平衡磁控溅射、脉冲磁控溅射技术、磁控溅射技术与其它成膜技术相结合等),以及国内外利用磁控溅射技术在多层膜和化合物薄膜制备方面取得的一些成果.     

高性能SS-AlN金属陶瓷真空太阳集热管的制备

采用真空磁控溅射沉积SS-AlN金属陶瓷太阳选择性吸收涂层.涂层光学功能层的制备,先采用铜靶溅射Cu红外反射层;再采用不锈钢(SS)和铝两金属靶在Ar和N2的混合气体中同时溅射沉积SS-AlN金属陶瓷吸收层;最后采用Al靶在Ar和N2中反应溅射沉积AlN减反射层.金属陶瓷吸收层由高、低SS体积份额的两吸收子层组成.优化溅射镀膜工艺参数获得高性能吸收涂层,太阳吸收比α(AM1.5)高达0.956±0.003(国标GB:α≥0.86),比GB高10％;红外发射比ε仅为0.043±0.003(GB:ε≤0.08).制备成φ58×2100 mm全玻璃真空太阳集热管,80℃平均热损系数ULT仅为0.47±0.01 W/m2℃ (GB:ULT≤0.85 W/m2℃),比GB低0.38W/m2℃,性能提高45％.制备的真空集热管具有良好的真空品质,集热管内管加热350℃恒温480 h后,吸气镜面轴向长度平均消失率仅为2～3％,集热管真空品质优于GB高达100倍以上(GB:350℃恒温48 h,镜面消失率≤50％).     

采用金-金键合工艺制备垂直结构氮化镓发光二极管(英文)

本文在采用键合工艺制备以硅为衬底的氮化镓发光二极管的工艺过程中分别尝试采用金-金,金-硅,铝-铝,铝-硅键合对。研究发现金-金键合对得到了100%的键合面积。键合工艺结束后,采用KrF激光分离氮化镓发光二极管的器件层和原蓝宝石衬底。通过超声波造影仪(SAM)和扫描电子显微镜(SEM)研究了金属键合工艺过程中相应的键合机制。     

SHS/QP制备(TiB2+Fe)/Fe叠层材料的结构与性能分析

采用SHS/QP工艺制备了(TiB₂+Fe)/Fe叠层材料。SEM分析表明TiB₂+Fe金属陶瓷层结构致密。用EPMA研究了TiB₂+Fe金属陶瓷层与Fe基片之间的界面连接机制,结果表明TiB₂从TiB₂+Fe侧向Fe基片侧进行扩散,以及TiB₂+Fe层中的Fe粘结相和Fe基片的粘接完成了(TiB₂+Fe)/Fe叠层材料的界面连接。叠层材料接头断裂时,断裂位置发生在TiB₂+Fe金属陶瓷层,而不是沿着TiB₂+Fe层与Fe基片的界面断裂。     

Sliding Wear Behavior of Plasma Sprayed Alumina-Based Composite Coatings against Al2O3 Ball

The sliding wear behaviors of a single layer AI2O3-30 wt pct ZrO2, a double layer AI2O3-30 wt pct ZrO2/Ni-Cr and a single layer AI2O3-13 wt pct TiO2 coating deposited on low carbon steel by plasma spraying were investigated under lubricated conditions with various normal loads. The plastic deformation, detachment and pull out of splats were involved in the wear process of the studied coatings under test conditions. Crack propagation was found in AI2O3-13 wt pct TiO2 under loads of 70 and 100 N and in AI2O3-30 wt pct ZrO2/Ni-Cr under a load of 130 N. While increasing the normal load, the wear rates of AI2O3-30 wt pct ZrO2 and AI2O3-30 wt pct ZrO2/Ni-Cr slightly increased, the wear rate of AI2O3-13 wt pct TiO2 increased rapidly. The results showed that the Ni-Cr bonding layer improved the wear resistance of the coating system even it is relatively thin compared with the outer coating layer. The influence of this bonding layer on wear behavior of the coating increased as increasing the normal load.     

致密TiC-Al2O3-Fe 金属陶瓷的自蔓延高温合成

通过自蔓延高温合成结合准热等静压法(SHS/PH IP) 制备出了致密的TiC₂Al₂O₃-20Fe 金属陶瓷。研究了延迟时间、高压持续时间、压力等工艺参数对金属陶瓷密实度的影响, 分析了金属陶瓷的相组成、微观组织及性能。结果表明, 燃烧合成过程中气体的排放和液相的存在是合成密实材料的关键, 通过优化工艺合成了密实度为97. 7% 的TiC₂Al₂O₃-20Fe 金属陶瓷。金属陶瓷由TiC、Al₂O₃ 和Fe 粘结相组成。粘结相Fe 与Al₂O₃ 之间界面光滑,Fe 与T iC 之间有一较薄扩散层。TiC₂Al₂O₃-20Fe 金属陶瓷的抗弯强度和抗压强度分别为890M Pa 和18. 4 GPa。      

Oxidation and Hot Corrosion of Gradient Thermal Barrier Coatings Prepared by EB-PVD

The performances of gradient thermal barrier coatings (GTBCs) produced by EB-PVD were evaluated by isothermal oxidation and cyclic hot corrosion (HTHC) tests. Compared with conventional two-layered TBCs, the GTBCs exhibite better resistance to not only oxidation but also hot-corrosion. A dense Al2O3 layer in the GTBCs effectively prohibites inward diffusion of O and S and outward diffusion of Al and Cr during the tests. On the other hand, an "inlaid" interface, resulting from oxidation of the Al along the columnar grains of the bond coat, enhances the adherence of AI2O3 layer. Failure of the GTBC finally occurred by cracking at the interface between the bond coat and AI2O3 layer, due to the combined effect of sulfidation of the bond coat and thermal cvcling.     

Recent progress on RE2O3-Mo/W emission materials

RE2O3-Mo/W cathodes were prepared by powder metallurgy method. La2O3-Y2O3-Mo cermet cathodes prepared by traditional sintering method and spark plasma sintering (SPS) exhibit different secondary emission properties. The La2O3-Y2O3-Mo cermet cathode prepared by SPS method has smaller grain size and exhibits better secondary emission performance. Monte carlo calculation results indicate that the secondary electron emission way of the cathode correlates with the grain size. Decreasing the grain size can decrease the positive charging effect of RE2O3 and thus is favorable for the escaping of secondary electrons to vacuum. The Scandia doped tungsten matrix dispenser cathode with a sub-micrometer microstructure of matrix with uniformly distributed nanometer-particles of Scandia has good thermionic emission property. Over 100 A/cm2 full space charge limited current density can be obtained at 950Cb. The cathode surface is covered by a Ba-Sc-O active surface layer with nano-particles distributing mainly on growth steps of W grains, leads to the conspicuous emission property of the cathode.     

TiC-Al2O3-Fe金属陶瓷的自蔓延高温合成研究

通过自蔓延高温合成结合准热等静压法（ＳＨＳ／ＰＨＩＰ）制备出了致密度为９７．７％的ＴｉＣ－Ａｌ２Ｏ３－２０Ｆｅ金属陶瓷（ＴＡＦ２０）。分析了金属陶瓷的相组成、微观组织及性能。结果表明：金属陶瓷由ＴｉＣ,Ａｌ２Ｏ３陶瓷颗粒和Ｆｅ粘结相组成;粘结相中Ｆｅ与Ａｌ２Ｏ３之间的界面光滑,与ＴｉＣ之间有一薄的扩散层;ＴＡＦ２０金属陶瓷的抗弯强度和抗压强度分别为８９０ＭＰａ和１８．４ＧＰａ。     

Highly conformal SiO2/Al2O3 nanolaminate gas-diffusion barriers for large-area flexible electronics applications

The present study demonstrates a flexible gas-diffusion barrier film, containing an SiO(2)/Al(2)O(3) nanolaminate on a plastic substrate. Highly uniform and conformal coatings can be made by alternating the exposure of a flexible polyethersulfone surface to vapors of SiO(2) and Al(2)O(3), at nanoscale thickness cycles via RF-magnetron sputtering deposition. The calcium degradation test indicates that 24 cycles of a 10/10 nm inorganic bilayer, top-coated by UV-cured resin, greatly enhance the barrier performance, with a permeation rate of 3.79 × 10(-5) g m(-2) day(-1) based on the change in the ohmic behavior of the calcium sensor at 20?°C and 50% relative humidity. Also, the permeation rate for 30 cycles of an 8/8 nm inorganic bilayer coated with UV resin was beyond the limited measurable range of the Ca test at 60?°C and 95% relative humidity. It has been found that such laminate films can effectively suppress the void defects of a single inorganic layer, and are significantly less sensitive against moisture permeation. This nanostructure, fabricated by an RF-sputtering process at room temperature, is verified as being useful for highly water-sensitive organic electronics fabricated on plastic substrates.