Properties of thin TiN films deposited onto stainless steel by an in-line dry coating process

A new coil-coating pilot plant, capable of utilizing ion plating, sputtering and plasma-assisted chemical vapor deposition (PACVD) processes, independently or in series, was developed and optimum conditions for TiN, TiC, Al_xO_y, SiO_x and Cr coating were established. This paper is mostly concerned with the results of characterization (conducted in parallel by the authors′ two institutions) of TiN films deposited by ion plating or sputtering onto type-304 stainless steel strips. In particular, the dependence of the basic properties such as chemical composition, structure, adhesion, and color on the coating process are discussed with respect to anti-corrosion, anti-wear, and decorative applications. TiN coatings with a very attractive gold coloration were obtained; they performed well in wear testing, but did not show satisfactory corrosion resistance. However, it was found that the latter can be improved significantly by depositing a SiO_x, top layer by PACVD above the TiN coating. Thus the in-line dry coating processes are capable of producing highly functional steel surfaces with decorative color and high corrosion resistance.     

Electrochromic properties of InN:Sn films deposited by reactive evaporation

Indium-tin nitride (InN:Sn) films were deposited by vacuum evaporation assisted by active nitrogen irradiation. A glancing-angle deposition scheme was applied to form isolated nanocolumnar structures in order to expand surface area of the films. X-ray diffraction analysis revealed that the films consisted of crystallites of InN:Sn in a wurtzite structure and amorphous InN:Sn matrix. The doped tin atoms did not work as donor in the InN:Sn films but electrons-trapping sites. The electrochromic amplitude was reduced with increase in tin composition. Despite that the tin doping caused the decrease in carrier density, the color-change region of the InN:Sn films shifted slightly toward shorter wavelength.     

Fatigue performance and microanalysis of heat treated 2205 duplex stainless steel

Abstract

The reduced corrosion fatigue performance of a heat treated grade of duplex SAF 2205 stainless steel has been quantified using Wöhler rotating bending fatigue machines. The reduction in fatigue performance has been related to elemental profiles around intergranular and intragranular precipitates and grain boundary segregation measured using EDAX analysis and scanning transmission electron microscopy.     

Reactive pulsed laser deposition of thin molybdenum- and tungsten-nitride films

In this work reactive pulsed laser deposition of molybdenum- and tungsten-nitride thin films is investigated. Metallic targets were ablated in low-pressure (1, 10 and 100 Pa) nitrogen atmosphere by KrF excimer laser pulses (fluence ∼6.5 J/cm²). Films were deposited on silicon wafers heated to ∼25, 250 and 500 °C. The characteristics of the films strongly depend on the N₂ pressure. By increasing N₂ pressure, the nitrogen content increases in the films, which leads to a monotonous increase of the electrical resistivity. Deposition rate decreases at 100 Pa as indicated by Rutherford backscattering spectrometry. At this pressure, hardness of the films significantly decreases also, as shown by microhardness measurements. X-ray diffractometry shows that films crystallinity is improved by increasing the substrate temperature. In addition, atomic force microscopy (AFM) and scanning electron microscopy (SEM) were applied for visualising the film surface.     

Analysis on microstructure and characteristics of TiAlN/CrN nano-multilayer films deposited by cathodic arc deposition

In this study, TiAlN/CrN multilayer thin films were deposited on SUS 403 stainless steel by cathodic arc deposition. The effects of substrate orientation (substrate surface parallel/perpendicular to target surface) and rotation speed were investigated in detail. Microstructure of the coatings was analyzed by X-ray diffraction, X-ray photoelectron spectroscopy and scanning electron microscopy. Meanwhile, tribological and corrosion tests were performed. The experimental results showed that the as-deposited films exhibit a nano-scale multilayer structure consisting of TiAlN and CrN phases. The TiAlN/CrN multilayer films prepared by a parallel orientation and a rotation speed of 4 rpm not only possesses the best coating hardness and hardness/elastic modulus ratio, but also reveals superior abrasion resistance and corrosion resistance.     

Structural studies on some doped CdS thin films deposited by thermal evaporation

The influence of the Mn, Se and Sb impurities on the structure and morphology of CdS thin films grown on p⁺ Si wafers was studied. The starting powders were mixed in the same molar ratios (0.3%) and deposited in the same conditions by vacuum thermal evaporation. X-ray diffraction(XRD), X-ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM) and reflectance studies made on thermal treated thin films (573 K, 2 h in air) evidenced that thin films have a hexagonal oriented structure, and that dopants enter into the CdS lattice merely by substitution. The dopant nature influences the thin film thickness and chemical composition. The doped CdS thin films have roughness in nanometer region and a reflectivity lower than 40%. Silicon substrate acts as a template and favors the retention of Mn and scatters the Sb dopants. The CdS:Se thin film is thicker than CdS:Mn and CdS:Sb ones and is a mixture of doped and undoped nanocrystals.     

Tribological property enhancement of CrN films by metal vapor vacuum arc implantation of Vanadium and Carbon ions

CrN films have been extensively used in precision forming and molding applications because of their excellent tribological properties and oxidation-resisting characteristics. Vanadium and carbon ions are introduced into the near surface layer of deposited CrN films via metal vapor vacuum arc implantation to improve the wear performance of CrN films. Dense and smooth CrN film was deposited using a filtered arc deposition system, which provides fully ionized Cr plasma on the substrate surface. Subsequently, surface bombardment of the deposited CrN film with vanadium and carbon ions densifies the film and forms an alloy near the surface. These CrN-based films were characterized by X-ray photoelectron electron and Auger electron spectroscopies. Examinations of the tribological and mechanical film properties, including wear resistance, corrosion resistance and fracture toughness were performed and correlated with respect to the implantation parameters.     

Influence of substrate temperature on CeF3 thin films prepared by thermal evaporation

We have investigated the effect of substrate temperature on the structural, compositional and electrical properties of cerium fluoride thin films prepared by thermal evaporation method. The structure of cerium fluoride is hexagonal and the growth orientation changes with increase in substrate temperature. The substrate temperature favors the growth of vertical nanorods on the surface of the thin films. The compositional analysis confirms the formation of cerium oxyfluoride, leading to free fluoride ions. Electrical conductivity increases with increasing substrate temperature.     

Synthesis and optical characterization of amorphous carbon nitride thin films by hot filament assisted RF plasma CVD

Carbon nitride thin films were synthesized by hot filament assisted radio frequency plasma chemical vapour deposition using methane and nitrogen gas mixture on silicon and glass substrates. The films were deposited at different substrate bias and at different substrate temperatures. At higher substrate bias (>−120 V) there was no deposition on the substrate, but complete etching of the deposited layer was observed. X-ray diffraction studies indicated the films were amorphous. The Fourier transform infrared spectra showed that the films produced exhibited high transmittance with the presence of the C-N stretching band at 1260 cm⁻¹. For the films deposited at a lower substrate temperature C=N peaks were also present. Raman spectroscopic study indicated the presence of D and G peaks whose relative height varied with substrate temperature. The transmittance versus wavelength measurement in the UV-VIS-NIR region showed the high transmittance in the NIR region. The optical band gap of the films was calculated to be 2.0 eV and the refractive index varied within 1.6-1.7 for the wavelength range 800-1800 nm.     

GaN thin films deposited by pulsed laser ablation in nitrogen and ammonia reactive atmospheres

Well-oriented, crystalline GaN films were grown on (11

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0) sapphire substrates in reactive atmospheres of N₂ and NH₃ by pulsed laser deposition. GaN targets were ablated at 2.8 J cm⁻² and the substrate temperature was varied from 500 to 700°C. The background gas pressure was varied from 0.04 to 0.3 mbar. All the films had a wurtzite structure. The crystal quality and preferential orientation depended on the substrate temperature, laser fluence and the presence of the nitriding atmosphere. For both N₂ and NH₃, the most resistive films were preferentially orientated in the [000l] direction. For 700°C the film resistivity was found to increase from 10⁻³ Ω cm when deposited in NH₃ to 10² Ω cm when deposited in N₂. The band-gap, obtained from optical transmission measurements shifted from 3.1 to 3.4 eV. Violet photoluminescence was found in all samples and was centered at 3.2 eV with a full width at half maximum of 0.2 eV. A broad peak in the yellow, centered at 2.1 eV, was detected for films grown in vacuum and ammonia.     

316不锈钢表面沉积厚类金刚石膜层的性能研究

采用脉冲辉光放电等离子体气相沉积法在316不锈钢表面沉积膜层较厚的类金刚石膜层。利用拉曼光谱仪(Raman)、X射线光电子能谱仪(XPS)、傅里叶变换红外光谱仪(FT-IR)、光学显微镜、显微硬度计和摩擦磨损实验机分别对膜层组成和微观结构及机械性能进行了表征。研究发现,通过脉冲辉光放电等离子体气相沉积法,在316不锈钢表面制备的类金刚石膜层光滑致密;Raman分析得到的ID/IG和IT/IG比值分别为0.72和0.22;FT-IR分析可知膜层含有较多的CHx组成的sp3键;摩擦磨损试验得到膜层的摩擦系数低至0.100,XPS分析膜层sp3含量高达60.7%和光学显微镜测量膜层的厚度达到7mm。由此可知沉积类金刚石膜层后,可以显著地改善316不锈钢表面的机械性能。     

装饰薄膜ZrN的中频反应磁控溅射沉积工艺研究

利用中频反应磁控溅射技术在1Cr18Ni9Ti不锈钢基底上沉积ZrN薄膜。通过控制N/Ar、溅射功率和基体偏压等参数,得到不同实验条件的ZrN膜层。通过对膜层颜色测量和AES分析,研究N分压强对ZrN膜层质量的影响。实验结果表明：工作气压0.3Pa,溅射功率5kW,基体偏压-150V、占空比50%等工艺参数一定的前提下,N分压强在不同的范围内,可以分别制备出视觉效果类似于18K、23K和纯金的氮化锆膜层。     

Diffusion barrier property of TiN and TiN/Al/TiN films deposited with FMCVD for Cu interconnection in ULSI

Flow modulation chemical vapor deposition (FMCVD) with titanium tetrachloride (TiCl₄) and ammonia (NH₃) is effective for depositing titanium nitride (TiN) films with conformal morphology, good step coverage, low electrical resistivity, and low chlorine residual contamination. It means that FMCVD TiN film is a good candidate of diffusion barriers for copper interconnection technology in ULSI. But the diffusion barrier property of FMCVD TiN film against Cu diffusion has not been confirmed. So, firstly, we deposited Cu (100 nm)/FMCVD TiN (25 nm)/Si multilayer films and investigated the thermal stability of Cu/TiN/Si structure. Vacuum annealing was done at 400, 500, 550 and 600 °C. For films annealed for 30 min at 400 °C, Cu diffused through the TiN layer and formed copper silicides on the surface of Si substrates. Therefore, FMCVD films formed under such conditions are unsatisfactory diffusion barriers. To enhance the diffusion barrier property of FMCVD TiN films, we used sequential deposition to introduce a monolayer of Al atoms between two TiN films. Etch-pit tests showed that for TiN films with Al interlayer, Cu diffusion through the barrier occurred at 500 °C and that is 100 °C higher than TiN film without Al interlayer. Al atoms formed AlO_x with oxygen atoms present in the TiN films as impurities, and fill up the grain boundaries of TiN film, thereby blocking the diffusion of Cu atoms.     

Effect of aging treatments and microstructural evolution on corrosion resistance of tungsten substituted 2205 duplex stainless steel

Abstract

The effect of partial substitution of tungsten for molybdenum on the microstructure and corrosion resistance in 22Cr–5Ni–3Mo duplex stainless steel (DSS) has been investigated following aging heat treatments in a temperature range of 600-1000°C. Electrochemical tests were carried out for the evaluation of corrosion resistance. Aging treatment had hardly influenced the general corrosion resistance. With the increase of aging time, the pitting corrosion resistance of the DSSs had decreased. After aging for 2 min at 700–900°C, the pitting potential of the 3Mo steel decreased remarkably, while that of the W substituted steel hardly changed. During aging, the intermetallic σ and secondary austenite (γ₂) phases were precipitated, and the pitting corrosion and intergranular corrosion resistance were significantly decreased after aging at 700–750°C for 10 h, which could be caused by the γ₂ formation. The γ₂ phase could effect the depletion of molybdenum and chromium in the γ₂ /α and γ₂/σ boundaries.     

Optical and electrical properties of ZnO nanoparticle thin films deposited on quartz by sparking process

ZnO nanoparticle thin films were deposited on quartz substrates by a novel sparking deposition which is a simple and cost-effective technique. The sparking off two zinc tips above the substrate was done repeatedly 50-200 times through a high voltage of 10 kV in air at atmospheric pressure. The film deposition rate by sparking process was approximately 1.0 nm/spark. The ZnO thin films were characterized by X-ray diffraction, Raman spectroscopy, UV-vis spectrophotometry, and ionoluminescence at room temperature. The two broad emission peaks centered at 483 nm (green emission) and 650 nm (orange-red emission) were varied after two-step annealing treatments at 400-800 °C. Moreover, the electrical resistivity of the films was likely to be proportional to the peak intensity of the orange-red emission.     

多弧离子镀在不锈钢板上沉积TiN的均匀性研究

本文对多弧离子镀在不锈钢板上沉积TiN涂层的均匀性进行了研究,分析了影响涂层均匀性的主要因素.结果表明,弧基距、磁场强度、气体压力及基片温度对涂层的均匀性起着决定性的作用.     

有机玻璃基材表面电子束蒸镀铬-铝-二氧化硅薄膜及其性能研究

采用电子束蒸镀的方法,以有机玻璃为基材,在其表面蒸镀铬过渡层,再蒸镀铝,最后蒸镀保护层二氧化硅.实验结果表明:增加铬过渡层的样品,铝膜结合的非常牢固,附着力得到很大的提高.和未蒸镀二氧化硅保护层的样品进行耐腐蚀性测试对比,发现二氧化硅薄膜具有很好的保护性,铝膜在10%的碱性溶液中完好无损;而没镀二氧化硅保护层的样品,铝膜很快溶解.试验结果表明,采用电子束蒸发技术,在使用合适的工艺参数下,可以在有机玻璃表面制备附着力好、耐腐蚀的高反射铝膜.     

The influence of deposition rate on the stress and microstructure of AlN films deposited from a filtered cathodic vacuum arc

Aluminium nitride (AlN) thin films have been reactively deposited using a filtered cathodic vacuum arc system. A pulsed substrate bias was applied in order to increase the average energy of the depositing species. The stress and microstructure of the films were determined as a function of the deposition rate and pulse bias amplitude/frequency. The stress generated in films grown with high voltage pulsed bias depended on the deposition rate and a transition from tensile stress to compressive stress occurred as the deposition rate increased. This trend was accompanied by progressive changes in the microstructure. In order of increasing deposition rate, the films exhibited: a porous structure with tensile stress; a dense AlN film with compressive stress; and a dense AlN film showing evidence of a thermally induced reduction in stress.     

不同能量离子束辅助沉积对形成氮化钛薄膜性能的影响

用不同能量离子束辅助沉积方法在医用不锈钢317L和Si(100)基底上沉积TiN薄膜。通过X射线光电子能谱(XPS)、X射线衍射(XRD)和俄歇电子能谱(AES)分析研究了薄膜的结构特征;测试了薄膜与基底的附着力和耐磨性;用电化学腐蚀的方法检测了薄膜在Hank’s模拟体液中的耐腐蚀性能;最后采用成纤堆细胞、骨髓细胞体外培养试验考察了生长于不同薄膜表面的细胞粘附、增殖、展布情况及细胞的形态。研究结果表明：用高、低能氮离子兼用的IBAD方法制备的TiN多晶薄膜比只用高能或低能沉积的薄膜具有更强的附着力和耐磨性,在Hank’s模拟体液中显示出更强的抗腐蚀能力,并在细胞体外培养中显示出良好的细胞相容性。     

Biofilm inhibition and corrosion resistance of 2205-Cu duplex stainless steel against acid producing bacterium Acetobacter aceti

Acid producing bacterium Acetobacter aceti causes pitting corrosion of stainless steel(SS).This work investigated the enhanced resistance of 2205-Cu duplex stainless steel(DSS) against biocorrosion by A.aceti in comparison with 2205 DSS using electrochemical and surface analysis techniques.With the addition of Cu to 2205 DSS,biofilms on the 2205-Cu DSS surface were inhibited effectively.The largest pit depth on 2205-Cu DSS surface in the presence of A aceti was 2.6 μm,smaller than 5.5 μm for 2205 DSS surface.The i_(corr) was 0.42±0.03 μA cm~(-2) for 2205-Cu DSS in the biotic medium,which was much lower than that for 2205 DSS(3.69±0.65 μA cm~(-2)).All the results indicated that the A aceti biofilm was considerably inhibited by the release of Cu~(2+) ions from the 2205-Cu DSS matrix,resulting in the mitigation of biocorrosion by A aceti.