离子刻蚀对磁控溅射氧化铝薄膜的影响

研究了PET薄膜表面经氩离子刻蚀后其物理性能的变化,经氩离子刻蚀后磁控溅射沉积Al2O3薄膜表面的测试结果表明:离子刻蚀使PET基体表面更加洁净;Al2O3与基体的结合强度增大;镀膜表面更加均匀;虽然对阻隔性的影响不大,但由于结合强度的增加,Al2O3膜在使用的过程中,膜层不易脱落,对保持阻隔性有一定的作用.     

AZ31B镁合金表面自蔓延反应火焰喷涂Al_2O_3基陶瓷层的组织结构及性能

为了提高火焰喷涂Al2O3基陶瓷涂层的致密度、结合强度和耐磨性,将铝热剂Al/CuO加入氧化铝钛粉(AT)陶瓷骨料中,采用自蔓延(SHS)反应火焰喷涂技术在AZ31B镁合金表面制备了Al2O3基复相陶瓷层,并对涂层的组织结构、致密度、抗热震性、结合强度和耐磨性进行了测试,分析了铝热剂对陶瓷层性能的影响。结果表明:与普通火焰喷涂制备的AT陶瓷层相比,SHS反应火焰喷涂制备的Al2O3基陶瓷层内部有Cu2+1O,Cu3TiO5,Al等新相生成,具有良好的致密度、结合强度和显微硬度,其耐磨性较普通火焰喷涂AT层提高较多。     

Al/Al2O3多层膜的表面和界面的分析研究

用热蒸发沉积和自然氧化及加热法制备纳米量级的Al/Al2O3薄膜和多层膜.用X射线光电子谱仪(XPS)和透射电镜(TEM)对样品进行检测.XPS实验说明自然氧化的Al2O3膜层厚在2～5 nm.Al/Al2O3薄膜及多层膜的O与Al的原子浓度比为1.43～1.85.Ar离子刻蚀的XPS实验结果(刻蚀速率为0.09 nm/s)说明2个对层的Al/Al2O3多层膜截面样品具有周期性结构.TEM观察到了5个对层的Al/Al2O3多层膜的层状态结构,其周期为4 nm.由此说明,热蒸发及自然氧化法是制备纳米量级的Al/Al2O3多层膜的有效方法.     

金属化温度对掺锰铬陶瓷封接性能影响的研究

研究了金属化烧结温度对掺锰铬陶瓷的封接性能的影响,初步分析了其影响原因与机理.结果表明:掺锰铬高氧化铝陶瓷对于MoMnSi配方的金属化反应活性高,1300℃是其最佳金属化温度,温度降低和升高都会导致封接性能降低.在最佳温度,金属化层烧结致密,金属化层与陶瓷间形成了主要由锰尖晶石(MnO·Al2O3)和少量硅氧化物构成的过渡层结构,从而将金属化层与陶瓷有效地连接在一起.温度升高使金属化层过度收缩会形成大量孔洞,元素氧化加剧,不利于过渡层的形成,导致封接性能大大降低.     

Al/Al2O3多层膜的表面和界面的分析研究

用热蒸发沉积和自然氧化及加热法制备纳米量级的Al/Al2 O3薄膜和多层膜。用X射线光电子谱仪 (XPS)和透射电镜 (TEM)对样品进行检测。XPS实验说明自然氧化的Al2 O3膜层厚在 2～ 5nm。Al/Al2 O3薄膜及多层膜的O与Al的原子浓度比为 1 4 3～ 1 85。Ar离子刻蚀的XPS实验结果 (刻蚀速率为 0 0 9nm/s)说明 :2个对层的Al/Al2 O3多层膜截面样品具有周期性结构。TEM观察到了 5个对层的Al/Al2 O3多层膜的层状态结构 ,其周期为 4nm。由此说明 ,热蒸发及自然氧化法是制备纳米量级的Al/Al2 O3多层膜的有效方法     

SHS陶瓷内衬复合管接合界面结构及力学性能研究

基于重力分离自蔓延过程,Al-Fe2O3-CrO3-TiO2-C燃烧体系,制备出了一种新型的FeO-TiC-Al2O3-CrO陶瓷内衬钢管,其内衬陶瓷层厚度均匀、致密、表面光滑.研究表明,加入TiO2、Na2B4O7和石墨后,在陶瓷/金属结合界面形成了Ti、Fe元素的梯度分布,B离子在Al2O3熔体表面的富集,改善了界面结合处Al2O3陶瓷熔体与铁合金过渡层之间的浸润性;双层梯度结构提高了陶瓷/金属界面结合强度,使复合管具有良好的力学性能.     

涂层结构设计对等离子喷涂陶瓷层结合强度及其应力的影响

用等离子在45#碳钢上喷涂了不同涂层设计的Al2O3以及Al2O3+130mg·g-1TiO2陶瓷层.用X-射线衍射法和拉伸实验测量了涂层表面层中的残余应力及结合强度.增加粘结层和过渡层能大大地克服陶瓷涂层与基材机械的以及热的不匹配性,使涂层的应力和结合强度都得到明显改善.此外,SiO2能改善ZrO2陶瓷层与基材以及陶瓷层内部的结合程度,使涂层内应力松弛并使其结合强度提高.然而SiO2添加剂只有在高熔点陶瓷层中(如ZrO2),"液相烧结"作用才明显,而在熔点较低的陶瓷层中(如Al2O3),这种作用并不明显.在用等离子喷涂低熔点Al2O3陶瓷时,添加适量的低熔点TiO2陶瓷是必要的.     

Al2O3涂层碳纤维/环氧基复合材料的性能研究

采用溶胶-凝胶法在碳纤维的表面涂覆了一层Al2O3涂层,透射电镜分析表明涂层中粒子的大小约为10nm,接触角分析表明涂层后碳纤维的表面张力有大幅提高.通过比较涂层前后碳纤维/环氧复合材料的力学性能发现,Al2O3涂层后复合材料的层间剪切强度,拉伸强度和弯曲强度分别提高了17.7%,4.8%和3.1%.扫描电镜分析表明,Al2O3涂层后的碳纤维与环氧树脂基体的结合更加紧密.且在碳纤维表面形成的Al2O3涂层在350℃～700℃能有效地减缓碳纤维环氧基复合材料的氧化失重速率.     

Ti(CN)/TiC/Al2O3/TiN多层涂层的结构和界面结合力研究

采用中温、高温复合化学气相沉积技术(MHCVD)在WC- (6％wt)Co硬质合金基体表面制备了Ti(CN)/TiC/Al2O3/TiN 多层陶瓷涂层.通过光学显微镜(OM)、扫描电镜(SEM)、X射线衍射仪(XRD)和数显显微硬度计等手段分析多层陶瓷涂层的表面及断面形貌、物相组成、显微硬度;采用表面划痕实验,结合形貌观察及X射线能谱分析(EDS)研究多层陶瓷涂层/硬质合金基体的界面结合力及其影响因素.结果表明:Ti(CN)/TiC/Al2O3/TiN 多层陶瓷涂层结构均匀致密,涂层后硬质合金的显微硬度明显提高,约2600 HV,多层陶瓷涂层与基体界面结合良好,划痕实验显示临界载荷高达105 N,多层陶瓷涂层界面间的原子扩散作用对涂层/基体界面附着力有较大贡献,而涂层内部少量Ti2O3、W6Co6C 等物相的存在对提高界面结合力也有帮助.     

不同铝源制备莫来石结合碳化硅多孔陶瓷及性能研究

以碳化硅(SiC)和不同铝源(多孔Al2O3/纳米Al2O3/Al(OH)3)为起始原料,通过原位反应结合工艺制备莫来石结合碳化硅多孔陶瓷。主要研究了不同铝源及温度对多孔陶瓷抗弯强度、气孔率、线性伸缩率等性能的影响,并采用XRD和SEM分析表征了样品的物相组成与断面形貌。结果表明:以多孔Al2O3为铝源,在1450℃下保温3h制备的碳化硅多孔陶瓷的综合性能最优,其强度为58 MPa,气孔率为41.9%;烧结温度对3种铝源所制备的多孔陶瓷具有相同的影响,随着温度的升高,强度逐渐升高,气孔率逐渐降低,线性收缩率逐渐增大。     

氧化铝陶瓷局部活化及选择性化学镀铜的研究

为解决陶瓷表面局部化学镀存在的问题,研制了一种针对氧化铝陶瓷局部化学镀铜前处理用的活化胶,其由具有活化能力的银盐(或钯盐)和粘稠的复合物有机载体组成.将活化胶印于氧化铝陶瓷表面,经500℃高温烧结形成局部活化层后,可直接置于化学镀液中进行镀铜处理,得到与印刷图形一致的局部镀铜层.利用电化学工作站测定样品在化学镀铜溶液中电位随时间的变化情况,考察不同活化条件对Cu2+还原的催化活性,利用SEM/EDS进行表面形貌及成分分析,确定了活化胶中银盐和钯盐的适宜浓度.结果表明,该两种活化胶应用于氧化铝陶瓷表面化学镀铜的活化工艺,可实现敏化活化的一步化,使陶瓷表面局部化学镀工艺流程简化,成本降低,具有较高的实用价值.     

ADHESION STRENGTH OF ELECTROLESS NICKEL DEPOSITS ON ALUMINA CERAMIC SUBSTRATE

Alumina ceramics are. widely used for LSI packages and printed circuit and sensor materials. For many of these applications, metallization of the surface is required. In general,this is performed by applying a conductive paste on the ceramic surface

An alternative approach is the subject of this paper. A wet process involving etching, catalytic activation, and electroless plating was investigated to deposit a nickel film with excellent adhesion. To obtain good adhesion of electroless nickel on alumina ceramics, ammonium fluoride etching, stannous chloride sensitizing and palladium chloride activation were used sequentially as preplating treatments. A dilute nickel bath with a 1:4 molar ratio of Ni to hypophosphite and a pH of 6 was optimal. Purging the bath with an inert gas improved nickel adhesion.     

镍/陶瓷复合膜的制备及表征

采用镍盐浸渍-液相化学还原法对氧化铝支撑体进行镍活化,再采用化学镀制备得到镍/陶瓷复合膜.采用XRD,SEM-EDS及气体渗透等方法表征镍/陶瓷复合膜的表面微结构、形貌及分离性能.结果表明:采用镍活化-化学镀过程可成功制备厚度较均匀的镍/陶瓷复合膜,在渗透压差0.08 MPa、室温的条件下,H2/N2分离因子为3.8.     

Preparation of AlN-Cu composite powders by electroless plating of controlled oxidized nitride particles to prevent degradation by hydrolysis

The present work describes the preparation of AlN-Cu composite powders by electroless plating. Initially, the hydrolysis reaction of the ceramic particles in the electroless solution was studied as a reference element for the design of a protective surface barrier that enabled the coating process, with no ceramic phase degradation. The metal source of the electrolytic bath was copper sulfate, with formaldehyde as the reducing agent, under alkaline conditions of pH 12. The microstructural characterization indicated the formation and growth of aluminum hydroxides from AlN particles, inhibiting the coating of Cu by increasing the OH⁻ ions in the solution. As the exposure time increased, the ellipsoidal bayerite grew from AlN and transformed into prismatic particles of the thermodynamically more stable gibbsite phase. To prevent the degradation of AlN, a controlled oxidation stage was implemented to form a protective barrier of non-reactive alumina on the surface through thermal treatment in oxidizing atmospheres. An atmosphere of dry air was found to be more appropriate than pure oxygen for the formation of a continuous and dense layer of crack-free alumina on nitride surfaces, and a temperature of 1000 °C for 1 h enabled the formation of 3.9 by weight of α-Al₂O₃, capable of reducing the hydrolysis reaction of AlN. The process of autocatalytic deposition on the passivated particles, applied in three consecutive steps of metallization, led to AlN-Cu composite powders with 29 wt% Cu. Finally, the coated powders were treated in a hydrogen-reducing atmosphere at 400 °C to remove traces of the Al(OH)₃ phase encountered, as well as to improve the adhesion of the nanostructured deposit of the cauliflower-like structure to the AlN surfaces, obtaining AlN-Cu composite powders suitable for the preparation of metal/ceramic composites.     

Development of alumina ceramics vacuum duct for the 3 GeV-RCS of the J-PARC project

An alumina ceramics vacuum duct has been developed for the 3 GeV-RCS of J-PARC project at JAERI. There are two types of alumina ceramics vacuum ducts needed, one being 1.5 m long with a circular cross-section for use in the quadrupole magnet, the other being 3.5 m long with a 15°, bend with a race-track cross-section for use in the dipole magnet. These ducts could be manufactured by joining several duct segments of 0.5-0.8 m in length by brazing. The alumina ceramic ducts have copper stripes on the outside surface to reduce the duct impedance. One of the ends of each stripe is connected to a titanium flange by way of a capacitor so to interrupt an eddy current circuit. The copper stripes are produced by an electroforming method in which a stripe pattern formed by Mo-Mn metallization is first sintered on the exterior surface and then overlaid by PR-electroformed copper (periodic current reversal electroforming method). In order to reduce emission of secondary electrons when protons or electrons strike the surface, TiN film is coated on the inside surface of the ducts.     

玻璃纤维增强双马来酰亚胺树脂基复合材料表面金属化的研究

采用化学方法对玻璃纤维增强双马来酰亚胺树脂基复合材料的表面进行镀前处理,以提高金属化镀层的质量。金属化工艺过程包括：材料的镀前处理,化学沉积铜,电镀铜和电镀光亮镍。实验结果表明,复合材料表面的粗化工艺对于镀层的质量具有重要的作用,经过适当的化学处理,使材料表面具有均匀适当的粗糙度,同时改善表面的亲水性,提高表面对活性钯催化剂的均匀吸附能力,能够提高镀层与基体的结合力。     

氧化铝泡沫陶瓷增强预制体上化学镀镍工艺研究

通过研究氧化铝泡沫陶瓷增强预制体上化学镀镍的前处理工艺,尤其是粗化、活化、敏化等步骤,并调整化学镀镍配方及工艺,成功地镀覆了厚度为数十个微米的镍层,初步解决了氧化铝陶瓷与铝基体（ZL102）的界面润湿问题。磨损试验结果证明效果明显。     

激光微加工对陶瓷表面化学镀铜的影响研究

采用扫描电镜(SEM)、X射线光电子谱(XPS)、X射线衍射能谱仪(XRD)等手段比较激光微加工处理前后陶瓷表面形貌发生的变化,探讨了激光微处理在陶瓷表面无敏化活化化学镀铜工艺中的作用.结果表明,陶瓷基底经激光处理后,其表面成分并未发生改变,但其表面活性增强,从而促进了化学镀铜反应的进行.     

Metallization of Kevlar fibers with gold

Electrochemical gold plating processes were examined for the metallization of Kevlar yarn. Conventional Sn(2+)/Pd(2+) surface activation coupled with electroless Ni deposition rendered the fibers conductive enough to serve as cathodes for electrochemical plating. The resulting coatings were quantified gravimetrically and characterized via adhesion tests together with XRD, SEM, TEM; the coatings effect on fiber strength was also probed. XRD data showed that metallic Pd formed during surface activation whereas amorphous phases and trace amounts of pure Ni metal were plated via the electroless process. Electrodeposition in a thiosulfate bath was the most efficient Au coating process as compared with the analogous electroless procedure, and with electroplating using a commercial cyanide method. Strongly adhering coatings resulted upon metallization with three consecutive electrodepositions, which produced conductive fibers able to sustain power outputs in the range of 1 W. On the other hand, metallization affected the tensile strength of the fiber and defects present in the metal deposits make questionable the effectiveness of the coatings as protective barriers.     

An in-situ formed ceramic/alloy/ceramic sandwich barrier to resist elements interdiffusion between NiCrAlY coating and a Ni-based superalloy

NiCrAlY coatings are widely applied on various alloy components to enhance oxidation and/or corro-sion resistance at high temperatures.However,elements interdiffusion occurs between them due to composition difference.Although various diffusion barriers(DBs)are reported,this problem is still far from completely solved as most ceramic barriers suffer from poor adherence,while the metallic barriers play a limited role.In this study,NiCrAlY coating was deposited onto a second-generation single-crystal superalloy by arc ion plating.A novel simple method is provided to address elements interdiffusion.By pre-oxidation at a moderate temperature,a thin scale of Ni(Co)O forms at the alloy surface.It transforms to be an alumina/NiCoCr alloy/alumina sandwich by an in-situ reaction with the overlaying NiCrAlY coat-ing and the alloy substrate at high service temperatures,which offers good barrier ability in conjunction with strong adhesion.In the presence of such an alumina/alloy/alumina DB,the NiCrAlY coating provides high resistance to oxidation and scale spallation for the alloy substrate.