AMORPHIZATION IN Nb-M (M=Fe, Co, Ni) BINARY METAL SYSTEMS INDUCED BY ION BEAM ASSISTED DEPOSITION (IBAD)

Ion beam assisted deposition technique (IBAD) was utilized to systematically study amorphization in binary metal systems of Nb-magnetic element, i.e., Nb-M (M=Fe, Co or Ni). The glass forming range termed as Nb fraction of Nb-Fe system was about 34at.% to 56at.%, that of Nb-Co system was about 32at.% to 72at.% and that of Nb-Ni about 20at. % to 80at. %. Similar percolation patterns were found in amorphous alloy films. The fractal dimensions of the percolation patterns approach to 2, which indicates 2-D layer growth for amorphous phases. It is regarded that the assisted Ar+ ion beam during the deposition process plays important role for the 2-D layer growth. Some metastable crystalline phases were obtained in these three systems by IBAD, e.g., bcc supersaturated solid solutions in Nb-Fe and Nb-Co systems, fcc and hcp phases in Nb-Co and Nb-Ni systems. The formation and competing between the amorphous and the metastable crystalline phases were determined by both the phases' thermodynamic states in binary metal systems and kinetics during IBAD process.

Tribological Properties of DLC Film Prepared by C^+ Ion Beam-assisted Deposition (IBAD)

C ^＋ ion beam-assisted deposition was utilized to prepare deposit diamond-like carbon （ DLC ） film. With the help of a series of experiments such as Raman spectroscopy, FT-IR spectroscopy, AFM and nanoindentation , the DLC film has been recognized as hydrogenated DLC film and its tribologicul properties have been evaluated. The bull-on-disc testing results show that the hardness and the tribologicul properties of the DLC film produced by C^ ＋ ion beam- assisted deposition are improved significantly. DLC film produced by C ^＋ ion beam- assisted deposition is positive to have a prosperous tribologicul application in the near future.

CORROSION BEHAVIOR OF Cu-Nb AND Ni-Nb AMORPHOUS FILMS PREPARED BY ION BEAM ASSISTED DEPOSITION

The Cu25 Nb75 and Ni45Nb55 amorphous films with about 500nm thickness were prepared by ion beam assisted deposition (IBAD). Potentiodynamic polarization measurement was adopted to investigate the corrosion resistance of samples and the tests were carried out respectively in 1mol/L H2SO4 and NaOH aquatic solution. The corrosion performance of the amorphous films was compared with that of multilayered and pure Nb films. Experimental results indicated that the corrosion resistance of amorphous films was better than that of the corresponding multilayers and pure Nb films for both Ni-Nb system with negative heat of formation and Cu-Nb system with positive heat of formation.

A New hcp Phase Formed in the Ni-Nb System during Ion-beam-assisted Deposition

The Ni80Nb20 films were prepared by ion beam assisted deposition (IBAD) with various Ar+ ion energies. A phase evolution of fcc→amorphous→Ni+Nb→Ni+hcp was observed with the increasing of ion beam energy from 2 keV to 8 keV. When bombarded by Ar+ ions of 8 keV during deposition, a new crystalline phase with hcp structure was obtained, of which the lattice parameters are a=0.286 nm and c=0.483 nm, different from those of the similar A3B-type hcp phase previously reported. The experimental results were discussed in terms of thermodynamics and restricted kinetic conditions in the far-from-equilibrium process of IBAD. The formation of hep phase may also be related to the valence electron effect.

Cr/CrN Compound Films Prepared by Ion Beam Assisted Deposition for Improving the Performance of Bearing Steel

With the development of industry, much attention has been paid to lengthening the life span of bearings. As reported in this paper, we investigated the Cr/CrN compound films formed on the specimens of W9Cr4V2Mo bearing steel by ion beam assisted deposition for improving the performance of bearing steels. The Vicker＇s microhardness, pin-on-disc, electrochemical measurement, XRD and SEM tests were used to characterize and analyze the treated samples. All results indicated that the mechanical properties of the treated samples were good, with the microhardness greater than that of the uncoated specimen, and the wear resistance, the passivity and pitting corrosion resistance increased considerably, the films possessed alternate Cr and CrN compound phases and produced different effects on the improvement of the performance of W9Cr4V2Mo bearing steels with different composing phases.

PREPARATION OF B-N FILMS BY ION BEAM ASSISTED DEPOSITION

BN films,synthesized by ion beam assisted deposition,were analysed by RBS,AES, IR spectra and TEM.Formatiom of c-BN phase was shown not only by IR spectra at absorption peak of 1100 cm^(-1),but also by electron diffraction pattern.The results of AES demonstrate an effect of N^+ implantation near the film surface.The deposited films consist of three layers,i.e.,ion implantation layer,film layer and mixed intermediatelayer, according to the difference of concentration.The micro-Knoop hardness of the film is 25—35 GPa.

The Effects of Annealing and Discharging on the Characteristics of MgO Thin Films Prepared by Ion Beam-Assisted Deposition as a Protective Layer of AC-PDP

This study investigated the effects of annealing and discharging on the characteristics of MgO thin films prepared by ion beam-assisted deposition as a protective layer of AC-PDP. By an annealing process at a temperature of 450 ℃ for more than three hours, the crystallinity of the deposited MgO films was improved, but the surface of the （200）-oriented MgO thin films in the vicinity of the discharge electrodes, especially on the inner sides of the electrodes, was subjected to crack formation to the compressive stress of The failure mechanism of the MgO films plus the additional （200）-oriented MgO films was due compressive stress induced by the differences in the coefficient of thermal expansion between the electrode and the dielectric layer. In the discharging process, all MgO films were eroded unevenly, and the serious erosion occurred near the edges of the discharge electrodes. ATM（atomic force microscopy） images show that the eroded surface of the （200）-oriented MgO thin film is smoother than that of the （111）-oriented fihn. Also, the （200）-oriented MgO thin film shows an improved ability to resist ion erosion compared to the （111）-oriented film.

Structural Characterization of Thin Epitaxial GaN Films on Polymer Polyimides Substrates by Ion Beam Assisted Deposition

The Epitaxial GaN thin films have been fabricated by Ion Beam Assisted Deposition (IBAD) process using nitrogen ions with hyperthermal energies on the polyimides polymer substrates. By applying with the Reflection of High-Energy Electron Diffraction (RHEED), Scanning Electron Microscopy (SEM) and Quantum Design Physical Properties Measurement System, the behaviour of hexagonal GaN thin films is investigated. The result showed that the high quality of the deposited GaN layers kept appearing for many parameters depending on the temperature greatly. The behaviour of high quality of epitaxial GaN coating on the polyimide polymer substrates is a promising material for optoelectronic devices and semiconductor devices application.

Microanalyses of the hydroxyl-poly-calcium sodium phosphate coatings produced by ion beam assisted deposition

Thin calcium phosphate catings on titanium alloy substrates were prepared by Ar^+ ion beam assisted deposition(IBAD) from hydroxyl-poly-calcium sodium phosphate(HPPA) target.The coatings were analyzed by XRD,FTIR,XPS,These analyses revealed that the as-deposited films were amorphous or no apparent crystallinity.No distinct absorption band of the hydroxyl group was observed in FTIR spectra of the coatings but new absorption bands were presented for CO3^-2,The calcium to phosphorous ratio of these catings in different IBAD conditions varied from 0.46 to 3.36.

A Study on Biocompatibility of TiN Thin Film Deposited on 317L Stainless Steel by Ion Beam Assisted Deposition

Titanium nitride ceramic thin films on 317L stainless steel(SS317L) substrate were deposited by Ion Beam Assisted Deposition (IBAD). The composition of the TiN films were investigated by Auger electron spectroscopy(AES), while the preferential orientation of the deposited film and phase composition were determined by X-ray diffraction(XRD). Adhesion was measured through Micro Scratch Tester(MST), and the corrosion resistance was evaluated by the electrochemical corrosion experiments in Hamk’s simulated human plasma. Specially, the biocompatibility of SS317L and TiN thin films were studied with fibroblast and marrow cell cultures in vitro. The results show that TiN thin films deposited on SS317L by means of IBAD can make remarkable changes on the structure and properties of the surface. At 37℃ Hank’s simulated plasma, free corrosion potential (E corr ) and breakthrough potential of pitting corrosion (E b) were both improved by coating TiN films . The culture results show that ion beam assisted TiN coatings exhibit a higher degree of cytocompatibility than that of SS317L and the cells grow better on those proper rough surfaces.

Effect of bombarding energy on ion beam assisted deposited DLC film on UHMWPE

Diamond-like carbon (DLC) films on ultra-high molecular weight polyethylene substrates were prepared at CHn+ ion bombarding energies of 200-1000eV at room temperature using ion beam assisted deposition technique. The wear tests exhibited a high wear resistance for all DLC films. X-ray photoelectron spectfoscopy and Raman spectroscopy analysis indicated that DLC film was amorphous with a characteristic high fracdion of sp3 bonds in the structure of mixed sp:2+ sp3 bonding at an optimal bombardingenergy of 600eV.

Fabrication of long-length ion beam-assisted deposited MgO templates for YBCO-coated conductors

The biaxially textured ion beam-assisted deposited(IBAD)-MgO templates were successfully prepared on polycrystalline Hastelloy metal substrate with reel-to-reel system for YB2Cu3O7-d(YBCO)-coated conductors.By the solution deposition planarization technique,amorphous Y2O3films were coated on untreated Hastelloy substrate as the bed layer to obtain smooth,dense,and crack-free surface for subsequent IBAD-MgO deposition.The 50 m long IBAD-MgO and homo-epitaxial(epi)-MgO buffer layers deposited on Y2O3films exhibit excellent crystallographic consistency along the scope with full width half maximum(FWHM)values of(110)DU and(200)Dx in the range of 5.5°–6.0°and3.0°–3.5°,respectively.To match the lattice constant of YBCO material,LaMnO3cap layer was fabricated on IBAD-MgO templates by radio frequency(rf)magnetron sputtering with the FWHM values of in-plane and out-ofplane of 6.8°and 3.7°,respectively,indicating excellent biaxial texture.

MoS_x FILMS DEPOSITED ON DIFFERENT MATRIXES BY ION BEAM TECHNIQUE

ＭｏＳ_ｘ ＦＩＬＭＳ ＤＥＰＯＳＩＴＥＤ ＯＮ ＤＩＦＦＥＲＥＮＴ ＭＡＴＲＩＸＥＳ ＢＹ ＩＯＮ ＢＥＡＭ ＴＥＣＨＮＩＱＵＥＷａｎｇＰｅｉｌｕ（王培禄）；ＬｉｕＺｈｏｎｇｙａｎｇ（刘仲阳）；ＪｉａｎｇＪｉｎｇｙｕｎ（姜景云）；ＧｏｕＦｕｊｕｎ（?..

A Review of Ion Beam Assisted Deposition of Thermal Barrier Coatings

Ion beam assisted deposition (IBAD) technology has been employed more and more in the fabrication of films and/or coatings,especially in the composite system.In the present work,after the introduction about IBAD,the latest development of IBAD in thermal barrier coatings (TBCs) is briefly summarized and the future trend is also concluded.

Structure and properties of carbon nitrogen films synthesized by ion beam-assisted deposition

β-C3N4 compound is a new hard material predicted by Liu and Cohen with theoretical calculation and so far it has not been found out in nature. In was assumed that the β-C3N4 compound would adopt the known crystal structure of β-Si3N4, which constructed a network of CN4 tetrahedra linked at the corners by threefold coordinate N atoms. Thus, the atomic coordination of β-C3N4 is sp3 hybrids on the C atoms and sp2 hybrids on the N atoms. Based on the theoretical analysis and modeling calculation, it

Hemocompatibility of DLC coatings synthesized by ion beam assisted deposition

Ion beam-assisted diamond-like carbon (DLC) coatings have beenused for growing the human platelet, fibrinogen, and albumin in the control environment in order to assess their hemocompatibility. The hard carbon films were prepared on polymethylmethacrylate (PMMA) at room temperature using ion beam assisted deposition (IBAD). Raman spectroscopic analysis proved that the carbon films on PMMA are diamond-like with a higher fraction of sp\+3 bonds in the structure of mixed sp\+2+sp\+3 bonding. The blood protein adsorption tests showed that DLC coatings can adsorb more albumin and are slightly more fibrinogen than the PMMA chosen as a control sample. The platelets adhered on DLC coatings were reduced significantly in number. These results indicate good hemocompatibility of DLC coatings.

高能束表面改性技术在航空领域的应用

高能束表面改性适用于各种金属和合金,能够显著提升材料表面硬度、耐磨、耐蚀等性能指标,是航空部件实现性能提升的有效手段之一。本文总结了6种高能束表面改性技术的基本原理、设备构成和改性应用,其中激光相变硬化通过马氏体相变强化金属材料表面;激光熔覆通过选择不同粉末实现表面修复和表面性能提升,重点在于控制裂纹缺陷;激光冲击强化可有效解决航空发动机部件高周疲劳断裂问题;强流脉冲电子束和强流脉冲离子束一方面需要提高设备的性能和运行稳定性,另一方面要针对航空部件应用开展深入研究;而离子束辅助沉积则可以通过制备固体润滑涂层实现对微动磨损的有效防护。最后,提出对高能束表面改性机理深入研究、发展专业化智能化装备和实现多种束源复合与集成的发展方向。

Influence of APS bias voltage on properties of HfO_2 and SiO_2 single layer deposited by plasma ion-assisted deposition

HfO2 and SiO2 single layer is deposited on glass substrate with plasma ion assistance provided by Leybold advanced plasma source （APS）. The deposition is performed with a bias voltage in the range of 70-130 V for HfO2, and 70-170 V for SiO2. Optical, structural, mechanical properties, as well as absorption and laser induced damage threshold at 1064 nm of HfO2 and SiO2 single layer deposited with the plasma ion assistance are systematically investigated. With the increase of APS bias voltage, coatings with higher refractive index, reduced surface roughness, and higher laser-induced damage threshold （LIDT） are obtained, and no significant change of the absorption at 1064 nm is observed. For HfO2, a bias voltage can be identified to achieve coatings without any stress. However, too-high bias voltage can cause the increase of surface roughness and stress, and decrease the LIDT. The bias voltage can be properly identified to achieve coatings with desired properties.

IBAD MoS_2-Ta膜的电子显微与能谱分析

用透射电子显微镜与能谱技术对离子束辅助沉积的ＭｏＳｏ２－Ｔａ膜的形态、结构、组成以及元素的化学态等进行了观察和分析。发现膜在沉积过程中已产生部分晶化，膜体出现衬度鲜明的白色“团簇”点缀的两相特殊形态。ＴＥＭ与ＸＰＳ分析确定白色“团簇”属析出的第二相ＴａＳ２。两区都具有（００２）、（１００）和（１１０）取向，面间距与晶格常数都比ＭｏＳ２单晶增大，“白区”的参数又比膜基体略大。去离子水浸泡和高温氧化实验表明，ＭｏＳ２－Ｔａ膜的耐水解、抗氧化能力远比同一条件沉积的ＭｏＳ２膜优越。

用离子束辅助沉积(IBAD)工艺制备TiC_xN_y膜的研究

用离子束辅助沉积（ＩＢＡＤ） 工艺在９Ｃｒ１８ 、ＧＣｒ１５ 钢基体上形成了ＴｉＣｘＮｙ 膜。ＴＥＭ 观察发现膜均呈多晶结构，都具有（１１１） 、（２００） 和（２２０） 择优取向。ＡＥＳ 和ＸＰＳ分析进一步证实，ＴｉＣｘＮｙ 膜呈含氧配置。干摩擦表明膜的抗氧化性能优良，其存在能有效抑制基体在摩擦过程中氧化膜的形成。又由于膜的硬度高，润滑性良好，每种基体的磨损特性都得到了显著地改善。但随着基体不同，膜的力学和机械性能随Ｎ 的注入量变化又表现出不同的变化规律。膜的硬度和摩擦特性与Ｎ 含量有关，总的趋势是过高的Ｎ含量对其硬度与摩擦特性造成不利影响。