NiTi合金表面类金刚石膜的表面特征和腐蚀行为

采用等离子浸没离子注入和沉积（PIIID）法以C2H2为等离子源对NiTi合金进行表面改性。利用Raman光谱分析膜层结构。采用原子力显微镜和纳米压痕分析涂层前后NiTi的表面形貌和力学性能。利用电化学测试、扫描电镜和原子吸收光谱测试涂层前后基体的耐腐蚀性和Ni离子析出。结果表明：NiTi合金表面的膜层是类金刚石（DLC）；经过PIIID处理后，基体表面的粗糙度降低；纳米硬度得到提高；耐腐蚀性能获得明显改善；Ni离子析出得到有效的抑制。     

Preparation, corrosion and structural properties of Cu–Ni multilayers from sulphate/citrate bath

Potentiostatic electrodeposition was used to produce Cu–Ni multilayer by two-wave pulse plating technique from sulphate/citrate electrolyte at pH 4. Cyclic voltammetry studies provide information about the deposition potential. The compositions of multilayers were studied using X-ray fluorescence (XRF). Electrochemical corrosion studies of the deposited multilayer on copper were studied by potentiodynamic polarization and electrochemical impedance spectroscopy (EIS). The surface of the layer having smooth, small grain and compact structure was confirmed by scanning electron microscopy (SEM) and atomic force microscopy (AFM) analysis. The face centered cubic lattices are present in the Ni–Cu multilayer and this is confirmed by the X-ray diffraction (XRD) data. The multilayer structures have better corrosion resistance than the base substrate.     

Characteristics of Ni-Ir and Pt-Ir hard coatings surface treated by pulsed Nd:YAG laser

The subjects of the presented paper are to develop a laser surface treatment technology for the protective coatings of glass-molding dies and to better understand the interaction between laser beam and materials coated on the die surface. A variety of alloy films, including Ir-25 at.% Pt, Ir-50 at.% Pt, Ir-75 at.% Pt, Ir-25 at.% Ni, Ir-50 at.% Ni, and Ir-75 at.% Ni compositions are deposited by the ion source assisted magnetron sputtering system (ISAMSS). A Cr layer that functioned as a buffer layer is deposited between the alloy film and die surface. After an alloy film and the buffer Cr layer were sequentially coated on tungsten carbide (WC) surface, Nd:YAG laser was directly applied in the writing process. The temperature profile of the film stack structure is simulated by ANSYS software. The surface roughness was analyzed by atomic force microscopy (AFM) to compare the coating surface roughness before and after the laser surface treatments. The treated coatings for oxidation prevention test were examined by energy dispersive x-ray spectrometry (EDS). Nanoindentation instrument was performed to evaluate microhardness and reduced modulus of the coatings. The cross-sectional structures between the hard coating layer and buffer layer were also inspected by a scanning electron microscope (SEM). The Pt-Ir and Ni-Ir film coatings are unable to withstand the working temperature over 1500 °C, which is considered for quartz molding process and hot embossing process. The films showed high roughness, low microhardness and low reduced modulus because the film oxidation occurred in a high working temperature process.     

负偏压对多弧离子镀制备的(Ti,Cr)N膜的影响

利用扫描电子显微镜、原子力显微镜等手段研究负偏压对多弧离子镀制备的(Ti,Cr)N薄膜表面缺陷、表面粗糙度、化学成分、沉积速率及硬度的影响。结果发现:随着负偏压的增加,(Ti,Cr)N薄膜的液滴受到抑制,表面粗糙度下降,沉积速率降低,硬度增加,但负偏压对薄膜的Cr含量影响较小。     

Low temperature processing of high conductivity and high transparency indium–tin-oxide/Ag alloy/indium–tin-oxide multilayered thin films

Indium–tin-oxide (ITO) thin films and ITO/Ag alloy/ITO multilayered thin films were deposited on glass substrates using a vertical in-line multilayer sputtering system. Ceramic ITO targets were used for the deposition of ITO layers at low substrate temperature of 100 °C. It was observed that the sheet resistance and light transmission of ITO films were affected by the oxygen pressure significantly. The ITO/Ag alloy/ITO multilayered thin films made in the present work had a low sheet resistance (6.9 Ω/□) and a high transmission (87.1%) at 550 nm. Atomic force microscopy (AFM) investigation showed that through selecting proper processing parameters, the surface roughness could be significantly reduced. The surfaces of ITO films were found very smooth by using pulsed-direct current (pulsed-dc) sputtering with introduction of H₂O. The work functions of the ITO films and ITO/Ag alloy/ITO multilayered films were increased with oxygen plasma treatment.     

Cu/Ni多层膜对Ti811合金微动磨损和微动疲劳抗力的影响

在Ti811钛合金表面利用离子辅助磁控溅射沉积技术制备20～1200nm不同调制周期的Cu/Ni金属多层膜,分析多层膜的结构,测试膜基结合强度、膜层显微硬度和韧性,对比研究不同调制周期的Cu/Ni多层膜对钛合金基材常温下微动磨损性能和微动疲劳(FF)抗力的影响。结果表明:利用离子辅助磁控溅射技术可以获得致密度高、晶粒细化、膜基结合强度高的Cu/Ni多层膜,该类多层膜具有良好的减摩润滑作用,因而改善了Ti811钛合金常温下抗微动磨损和微动疲劳性能;Cu/Ni多层膜对钛合金FF抗力的改善程度随膜层调制周期呈现非单调变化趋势,调制周期为200nm的Cu/Ni多层膜对钛合金FF抗力的提高程度最大,原因归于该膜层具有良好的强韧和润滑综合性能。     

电解抛光态690TT合金经不同时间浸泡后表面氧化膜结构分析

利用AFM,SEM,TEM,EDS及XPS分析了电解抛光处理690TT合金在含B和Li,充H_2的高温高压水溶液中经不同时间浸泡后表面生长氧化膜的微观结构.结界表明,从短期氧化到长期氧化,氧化膜表面形貌变化不明显;氧化膜主要由具有尖晶石结构的氧化物和单质Ni构成.浸泡720,1440和2160h后,氧化膜均由外层、中间层和内层构成:外层是分散的富含Ni和Fe的尖晶石结构的大颗粒氧化物;中间层是疏松的富含Ni的尖晶石结构的针状氧化物;内层是连续致密的富Cr氧化物.仅氧化膜中的内层氧化物能对基体起到良好的保护作用.电解抛光处理不利于690TT合金表面保护性氧化膜的快速生长.浸泡至2160 h后,氧化膜依然缺乏保护性.内层氧化膜的平均生长速率并未显著降低.     

Cu对TiNi记忆合金耐腐蚀性能的影响

用电化学极化方法研究了Cu含量及溶液pH值对Ti50Ni50-xCux合金在1%NaCl溶液中的耐蚀性的影响。结果表明,Cu的加入可显著提高合金的再钝化电位,而对点蚀电位在x<6时则无明显影响。溶液pH值升高时,点蚀电位提高。而再钝化电位则不受pH值影响。     

Magnetism and work function of Ni-Cu alloys as metal gates

The magnetism and work function of pure Ni(001) and Ni-Cu slab alloys were investigated using first-principles methods based on density functional theory. The calculated results reveal that both magnetic moments and work functions of the alloys depend strongly on the surface orientation, but hardly on the distribution of doped Cu atoms for a given surface orientation. It is found that the doped Cu atoms have evident influence on the magnetic moment of Ni-Cu slabs, and the average magnetic moment of Ni atoms for Ni-Cu alloys decreases with increasing concentration of Cu atoms. Moreover, it is observed that the work function of Ni(001) is insensitive to the supercell thickness and the inner concentration of Cu atoms. In the meantime, the spin polarization is found to have an obvious role on the work function of the Ni-Cu alloys, which may give a new way to modulate the work function of the metal gate.     

磁控溅射Cu膜表面形貌演化的多尺度行为

用原子力显微镜(AFM)观察磁控溅射Cu膜的表面形貌,并基于功率谱密度(PSD)和粗糙度测量方法对薄膜进行了量化表征,研究了薄膜表面演化的动力学标度行为.结果表明:薄膜表面演化具有多尺度特征,在全域和局域呈现两种不同的标度行为.全域的粗糙度指数αg≈0.83,生长指数βg≈0.85;而局域的粗糙度指数α1≈0.88,生长指数β1≈0.26.这种差异揭示了薄膜生长机制的尺度依赖性.薄膜全域表面演化为异常标度行为,这归因于体扩散导致了晶粒几何形态的急剧变化;而局域表面演化呈现表面扩散控制的生长行为.     

Scaling Behaviors of Surface Roughening of Cu Thin Films Deposited by Oblique Angle Deposition

Cu thin films with different thicknesses were deposited by magnetron sputtering at various oblique angle θ of incidence between the deposition flux and the substrate surface normal.Cross-section microstructure and surface morphology of the films were investigated by scanning electron microscope(SEM)and atomic force microscope(AFM),respectively.Then the scaling behaviors of film surface roughening were analyzed in terms of dynamic scaling theory.With the increasing of the deposition angle θ,the angleφbetween grain growth direction and substrate surface normal increased gradually.With increasing θ in the range of<50°,the roughness exponent α increased from 0.76 to 0.82 and the growth exponent β decreased from 0.42 to 0.35.However,when θ increased to 70°,α and β changed to 0.72 to 0.61,respectively.The evolution of the scaling exponents effectively revealed the fact that the film surface roughening arises from the competition between surface diffusion and shadowing effect.     

The influence of pulse parameters on Zn-Ni alloy coatings plated on AZ91 magnesium alloy

The influence of pulse parameters on zinc-nickel coatings plated on AZ91 magnesium alloy is investigated by scanning electron microscopy (SEM) and X-ray diffraction (XRD). The particles of zinc-nickel alloy plated on AZ91 magnesium alloy become smaller and the surface roughness decreases with the increase of current density and frequency. However, long plating times and a high ratio of t_on/t_off have decremental effects on the particles and surface roughness. The contents of crystal phases of zinc-nickel alloy coatings are higher under pulse current deposition than under direct current. The frequency, current density, plating time and ratio of t_on/t_off have different impacts on the thickness and Ni content of zinc-nickel coatings.     

Formation of oxidation-resistant Cu-Mg coatings on (001) Cu for oxide superconducting tapes

The formation of oxidation-resistant buffer layers on (001) oriented Cu for coated high-temperature superconducting tape applications was investigated. The approach employed Cu/Mg multilayer precursor films that were subsequently annealed to form either Mg-doped fcc Cu or intermetallic Cu₂ Mg. The precursor consisted of an Mg/Cu multilayer stack with 5 each of 25 nm thick Mg and 25 nm thick Cu layers which were grown at room temperature by sputter deposition. At annealing temperature of 400 °C, formation of the intermetallic Cu₂ Mg was observed. X-ray diffraction showed that the Cu₂ Mg (100) oriented grains were epitaxial with respect to the underlying Cu film, possessing a cube-on-cube orientation. In order to test oxidation resistance, CeO₂ films were deposited at elevated temperature on Ni/(Cu,Mg)/Cu/MgO structures. In case of the CeO₂ film on Ni/Cu/MgO, significant surface roughness due to the metal oxidation is observed. In contrast, no surface roughness is observed in the SEM images for the CeO₂/Ni/(Cu,Mg)/Cu/MgO structure.     

In-situ thermal evolution of Ni/Ti multilayer thin films

Nickel and titanium alternated nanolayers were deposited from Ti and Ni targets. The multilayer thin films were designed in order to have equiatomic overall chemical composition with a period from 5 to 70 nm. The chemical composition, morphology, structure and phase transformation behaviour were studied. The surface and cross-section morphology of the as-deposited thin films was analysed by atomic force microscopy (AFM) and scanning electron microscopy (SEM). The Ni/Ti thin films present in their surface nanograins and for higher periods in cross section it was possible to distinguish the alternated layers and measure their thickness. The structural evolution with temperature was analysed by in-situ hot stage X-ray diffraction (XRD). The as-deposited multilayer thin films exhibit a tendency to a transitory disorder as the period decreases. For the smaller periods a disordered phase forms during the deposition process, while in Ni/Ti multilayers with higher periods this phase is only observed during annealing. By increasing the temperature an exothermic reaction occurs with the formation of the B2-NiTi austenitic phase. In spite of moderate enthalpy of mixing, the multilayers with intermediate modulation period of Ni/Ti films show potential to be used for joining purposes.     

Roughness analysis of CVD Cu films on different substrates by AFM imaging

The roughness analysis of chemical vapor deposition (CVD) of copper (Cu) thin films on various substrates with and without seed layers was studied using atomic force microscopy (AFM). The effect of the seed layers on the film morphology was investigated, and none of the seed layers on the substrates improved the film morphology compared with TiN.     

微波等离子体改性对金刚石薄膜表面亲水性的影响

采用微波等离子体法,分别使用H和O等离子体对金刚石薄膜表面进行改性处理.通过扫描电子显微镜(SEM),原子力显微镜(AFM),X射线光电子能谱(XPS),并结合接触角随时间变化的曲线,初步评价了改性前后薄膜表面显微结构和成分的变化对亲水性的影响.结果表明:同一条件下制备的金刚石薄膜表面形貌、粗糙度差异不会影响表面亲水性;改性前金刚石薄膜亲水性差,H、O等离子体改性后薄膜表面接触角由原来的81°下降到20°以下,形成了亲水性良好的表面;暴露在空气中后,接触角在前3天的变化很大,这种变化与薄膜表面成分的改变密切相关.     

Effect of immersion Ni plating on interface microstructure and mechanical properties of Al/Cu bimetal

A nickel-based coating was deposited on the pure Al substrate by immersion plating, and the Al/Cu bimetals were prepared by diffusion bonding in the temperature range of 450–550 °C. The interface microstructure and fracture surface of Al/Cu joints were studied by scanning electron microscopy (SEM) and X-ray diffraction (XRD). The mechanical properties of the Al/Cu bimetals were measured by tensile shear and microhardness tests. The results show that the Ni interlayer can effectively eliminate the formation of Al-Cu intermetallic compounds. The Al/Ni interface consists of the Al₃Ni and Al₃Ni₂ phases, while it is Ni-Cu solid solution at the Ni/Cu interface. The tensile shear strength of the joints is improved by the addition of Ni interlayer. The joint with Ni interlayer annealed at 500 °C exhibits a maximum value of tensile shear strength of 34.7 MPa.     

Electrochemical Deposition of Ag,Au and Ag-Au Alloys on n-Si(111)

The mechanisms of silver and gold-silver alloy electrodeposition on n-Si(III) in a cyanide medium have been studied combining electrochemical and surface analytical techniques. The kinetics during the initial stages of deposition were investigated by cyclic voltammetry and chronoamperometry combined with AFM and SEM. The conditions for progressive and instantaneous primary nucleation were elucidated from the analysis of current transients. Based on experimental results a double pulse routine (including a short nucleation pulse to a relatively high cathodic potential E₁ followed by a low growth potential E₂ was introduced for obtaining continuous and adherent thin metal films. The morphology of deposited films was found to be strongly dependent on the growth potential. The influence of deposition conditions on composition of Ag-Au alloy films was investigated by EDX and XPS. Current-voltage and capacity-voltage measurements showed an ideal Schottky behaviour of the n-Si/Ag, n-Si/Au and n-Si/alloy solid-state contacts, and the formation of high quality junctions in all cases. Specific aspects of metallisation of n-Si/SiO₂ microstructure arrays, applying the double pulse polarisation technique, are discussed. The use of the so-called capillary based electrochemical microcellfor localised metallisation on microstructure arrays is demonstrated.     

工艺参数对铜锰合金镀层组织和成分的影响

目的在基体表面制备出均匀平整、致密且与基体结合良好的合金镀层,合金镀层中Mn的原子数分数达20%以上。方法用电沉积方法以氯酸盐体系,用EDTANa2作为络合剂,在SUS430不锈钢表面制备了Cu-Mn合金镀层,利用SEM及EDS研究了镀层的微观形貌及成分变化,分析了电流密度、pH值、沉积时间、电解液中n(Cu):n(Mn)比等参数对镀层微观结构和成分的影响。结果电流密度为200~700 m A/cm~2、pH值为3~7、时间为10~30 min和n(Cu):n(Mn)比为1:20~1:10时,镀层中的Mn含量随电流密度、pH值及时间的增大而增大,随着n(Cu):n(Mn)比值的增大而减小。结论电镀Cu-Mn合金的优化工艺参数是:电流密度为500 m A/cm2,pH值为5,时间为20 min,n(Cu):n(Mn)比为1:10。此时能够得到均匀、致密、与基体结合良好的合金镀层,且合金镀层中Mn的原子数分数能达到20%以上。质量良好的Cu-Mn合金镀层在固体氧化物燃料电池中具有潜在的应用价值。     

AlCrTaTiZrV高熵合金氮化物扩散阻挡层的制备及其热稳定性

为研究氮气含量的变化对AlCrTaTiZrV高熵合金薄膜性能的影响,检验在最佳氮气含量下厚度为15 nm的(AlCrTaTiZrV)N扩散阻挡层的热稳定性。采用直流磁控溅射设备在N型Si(111)基底上溅射不同氮气含量的高熵合金氮化物;选取最佳氮气含量为制备条件,在硅基底上沉积15 nm厚的AlCrTaTiZrVN₁₀高熵合金氮化物为扩散阻挡层,并在阻挡层顶部沉积50 nm厚度的Cu膜,最终形成Si/AlCrTaTiZrVN₁₀/Cu三层堆叠结构。利用真空退火炉将Si/AlCrTaTiZrVN₁₀/Cu薄膜体系在500 ℃下进行不同时间的退火处理,用以模拟恶劣的工作环境。利用场发射扫描电子显微镜(FESEM)、原子力显微镜(AFM)、X射线衍射仪(XRD)及四探针电阻测试仪(FPP)对试样的表面形貌、粗糙度、物相组成及方块电阻和进行表征。试验结果为:当氮气含量低于10%时,高熵合金氮化物薄膜为非晶结构。当氮气含量为20%时,高熵合金氮化物薄膜呈现FCC结构,并随着氮气含量的增加,薄膜的结晶性得到提高。薄膜表面的粗糙度在氮气含量为10%时最低,R_a仅为0.124 nm。三层堆叠结构500 ℃退火8 h后,Cu表面发生团聚,薄膜的方阻维持在较低的0.070 Ω/□,且并未发现Cu-Si化合物。厚度为15 nm的非晶结构AlCrTaTiZrVN₁₀薄膜在500 ℃退火8 h后,依旧可以抑制Cu的扩散,表现出了优异的热稳定性及扩散阻挡性能。