Influence of the nitriding and TiAlN/TiN coating thickness on the sliding wear behavior of duplex treated AISI H13 steel

AISI H13 die steel substrates were low pressure gas nitrided to different thicknesses and hardness values. Nitrided and non nitrided samples were subsequently coated with bi-layer TiAlN/TiN to two different thicknesses. The hardness was measured across the coating thickness and observed to be higher when a thinner coating was deposited over nitrided substrates. The hardness behavior across relatively thin (3 μm) coatings was not affected by the nitrided surface hardness or thickness of the nitride layer in the range of values examined here (80-150 μm). On the other hand, the hardness behavior of thicker coatings (8um) was affected by the nitrided layer, as the thicker coatings were soft due to their columnar structure. The specific wear rate of the duplex coatings was affected by the coating thickness and hardness distribution across the coating system.     

不锈钢根管锉镀覆TiN、ZrN膜的沉积工艺与性能研究

目的通过在不锈钢根管锉表面镀覆Ti N、Zr N薄膜,以提高其切削性能。方法采用磁控溅射技术,调整沉积时间、基片偏压、占空比等工艺参数在不锈钢根管锉上分别沉积Ti N、Zr N薄膜。对Ti N、Zr N膜层进行SEM断面分析、XRD相组成分析、表面硬度测试、膜层附着力测试,考查了Ti N、Zr N薄膜的厚度、相组成、硬度以及附着力。通过对镀膜后的根管锉进行电化学腐蚀试验、模拟临床切削试验,分析了镀膜后根管锉的耐蚀性和切削性能。结果随着工艺参数的变化,Ti N、ZrN薄膜的厚度、相结构以及硬度均显示了规律性的变化。镀覆Ti N、Zr N薄膜的不锈钢根管锉的自腐蚀电流密度相对于未镀膜的根管锉均明显降低。确定了Ti N膜层和Zr N膜层的优化沉积工艺分别为沉积时间1 h、负偏压100 V、占空比60%和沉积时间1h、负偏压150V、占空比60%。优化工艺下镀膜的不锈钢根管锉的切削数量和切削效率显著提高。结论和未镀膜不锈钢根管锉相比,镀覆Ti N、ZrN薄膜的不锈钢根管锉的表面硬度、耐蚀性能均有显著提高。最优工艺下制备的镀覆Ti N、Zr N薄膜的不锈钢根管锉兼具切削数量、切削效率以及切削稳定性等方面的综合优势,和未镀膜不锈钢根管锉相比,切削效率提高60%～75%,切削树脂模拟根管数量达到1.7～2倍,实现了切削性能的显著提升。     

Nanomechanical and electrochemical properties of ZrN coated NiTi shape memory alloy

Zirconium nitride (ZrN) thin films were deposited on NiTi and Si substrates in the 23–570 °C temperature range by direct current reactive magnetron sputtering using N₂/Ar gas mixture. The film hardness, corrosion behavior, phase composition, and texture were determined. The deposited films were composed mainly by the cubic ZrN phase, whose texture varies with substrate temperature, changing progressively from (111) to (200) texture as the temperature increases. The hardness of the films is influenced by the texture and has a linear relationship with the ratio of the texture coefficients P(111)/P(200). The higher hardness is obtained for ZrN thin films with (200) texture. Electrochemical tests show that NiTi coated with (200)-oriented ZrN films has higher tendency to passivation and greater stability of the passive film as compared to (111)-oriented ZrN films, despite no abrupt changes was observed when the texture changes from (111) to (200).     

Microstructure and hardness of hollow cathode discharge ion-plated titanium nitride film

Titanium nitride (TiN) films were deposited on 304 stainless steel substrate by hollow cathode discharge (HCD) ion-plating technique. The preferred orientation and microstructure were studied by x-ray diffraction (XRD) and transmission electron microscopy (TEM), respectively. Microhardness of the TiN film was measured and correlated to the microstructure and preferred orientation. The results of TEM study showed that the microstructure of TiN film contains grains with nanometer scale. As the film thickness increases, the grain size of TiN increases. The x-ray results show that TiN(111) is the major preferred orientation of the film. The hardness of TiN film is primarily contributed from TiN(111) preferred orientation.     

氮化钛薄膜二次电子发射特性研究

目的研究氮化钛薄膜的部分物理特性及真空中的电子发射特性,验证氮化钛薄膜具有相对较好的电导特性及较低的电子发射系数,证明氮化钛薄膜在空间大功率微波器件表面处理中有良好的应用前景。方法使用射频磁控溅射技术在单晶硅及玻璃片表面制备氮化钛薄膜,实验中通过调节溅射过程中氮气与氩气的气体流量比控制薄膜中的氮钛原子比。使用SEM对氮化钛薄膜的表面形貌及厚度进行表征。使用超高真空二次电子发射特性研究平台对氮化钛薄膜的二次电子发射特性进行表征。结果通过调节溅射过程中的氮气氩气流量比,能够有效控制薄膜中氮钛两种元素的含量,进而改变氮化钛薄膜的结晶方式和其他物理特性。当氮氩气体流量比约为10:15时,薄膜中氮钛原子比约为1:1。电阻率测试结果表明,薄膜中氮钛原子比越接近1:1,薄膜的电阻率越低。二次电子产额(SEY)测试结果表明,所制备氮化钛薄膜的最小SEY峰值约为1.46,低于平滑金(~1.8)、银(~2.2)表面的SEY。结论氮化钛薄膜具有较好的电导特性及较低的SEY,且其在真空环境中有良好的稳定性,能在不影响微波器件表面损耗的情况下,有效降低器件表面发生电子倍增的风险。     

A comparative study of the properties of TiN films deposited by MAIP and FCAP

In this study two types of TiN films were prepared, one using the filtered cathodic arc plasma (FCAP) technique with an in-plane “S” filter, and the other using the multi-arc ion-plating (MAIP), and both deposited under the same parameters. Comparisons of the texture, hardness, roughness, tribological and electrochemical corrosion behaviors of the two types of TiN films were given. The TiN films obtained by the FCAP technology were found to be highly uniform, smooth and macroparticle-free. The TiN films deposited by FCAP had a (111) preferred orientation, while there was no texture in the films deposited by MAIP. Under low load the two kinds of TiN coatings had very different wear mechanisms; the films of FCAP had a lower wear rate and friction coefficient compared with the TiN films deposited by the MAIP technique. The dense and hole-free structure of TiN films of FCAP could effectively avoid the avalanche of TiN films from the substrate during corrosion tests.     

Abnormal growth of “giant” grains in silver thin films

Abnormal growth of “giant” grains in the millimeter range was observed in silver thin films with thicknesses of 2.0 and 2.4 μm. The effect depends on deposition temperature and deposition geometry. The microstructure and texture of as-deposited and annealed films have been characterized using X-ray, electron backscatter diffraction (EBSD) and focused ion beam (FIB) techniques. Abnormal grain growth is found whenever a special texture is formed during film deposition. Otherwise normal grain growth occurs. The texture type—and thus the grain growth mode—can be controlled by adjusting the process parameters. During abnormal grain growth, the initial 〈111〉 texture transforms completely into 〈001〉. Growth of 〈111〉-oriented grains stagnates at a size smaller than the film thickness with a non-columnar grain structure. This stagnation promotes orientation-selective growth of 〈001〉 grains.     

热处理对PI基板铜薄膜金属化TiN阻挡层的影响

聚酰业胺(PI)材料具有介电常数低，分解温度高及化学稳定性好等优点，是很有前途的电子封装材料。Cu具有低的电阻和高的抗电迁移能力，足PI基板金属化的首选材料。采用物理气相沉积(PVD)方法在PI基板上沉积Cu薄膜，利用TiN陶瓷薄膜阻挡Cu向PI基板内部扩散。研究热处理条件下TiN陶瓷薄膜阻挡层的阻挡效果、Cu膜电阻变化以及Cu膜的结合强度，俄歇谱图分析表明TiN可以有效地阻挡Cu向PI内的扩散。300℃热处理消除了Cu膜内应力，提高了Cu膜的结合强度。     

Interface activation and surface characteristics of Ti/TiN/HA coated sintered stainless steels

Interface activation and surface characteristics of Ti/TiN/HA film coated sintered stainless steels (SSS) have been investigated by electrochemical and biocompatibility tests. HA (hydroxyapatite), Ti, and Ti/TiN film coatings were applied using electron-beam deposition method (EB-PVD). Ti, Ti/TiN, and Ti/TiN/HA film coated surfaces and layers were investigated by SEM and XPS. The coated films showed micro-columnar structure, and Ti/TiN/HA films were denser than Ti or HA-only film. The corrosion resistance of the HA coating was similar to that of Ti/TiN/HA film coating when Cu content reached 4 wt.%, but the corrosion resistance of the HA coating decreased when Cu content increased from 4 wt.% in 0.9% NaCl solution. Therefore, HA-only coating could ensure corrosion resistance when Cu content does not exceed 4 wt.%. The results of biocompatibility tests of SSS on dogs showed that bone formation and biocompatibility were favorable when Cu content did not exceed 4 wt.%. The biocompatibility with bone was generally favorable in Ti/TiN/HA film coating and HA-only coating, while bone formation was somewhat faster for the HA film coated surface than for the Ti/TiN/HA film coating. Also, good cell growth and osseointegration without toxicity were observed.     

Nanocrystalline titanium nitride films prepared by electrophoretic deposition

Homogeneous and adhesive nanocrystalline TiN thin films are fabricated on Ti substrates by electrophoretic deposition in an aqueous suspension containing TiN powders at room temperature. X-ray diffraction confirms the formation of TiN films and the film color varies with deposition time. The current-time curves are recorded during deposition and the surface morphology and cross-sectional images are investigated by scanning electron microscopy (SEM). The film thickness is around 6.1 μm after 10 min deposition and increases with deposition time. The adhesion strength is characterized by the ultrasonic vibration method and peel-off test. Our results suggest that electrophoretic deposition is a practical and facile technique to prepare nanocrystalline TiN films that are particularly suitable for the decorative coating industry.     

Effect of Axial Magnetic Field on the Microstructure,Hardness and Wear Resistance of TiN Films Deposited by Arc Ion Plating

TiN films were deposited on stainless steel substrates by arc ion plating. The influence of an axial magnetic field was examined with regard to the microstructure, chemical elemental composition, mechanical properties and wear resistance of the films. The results showed that the magnetic field puts much effect on the preferred orientation, chemical composition, hardness and wear resistance of TiN films. The preferred orientation of the TiN films changed from(111) to(220) and finally to the coexistence of(111) and(220) texture with the increase in the applied magnetic field intensity. The concentration of N atoms in the TiN films increases with the magnetic field intensity, and the concentration of Ti atoms shows an opposite trend. At first, the hardness and elastic modulus of the TiN films increase and reach a maximum value at 5 m T and then decrease with the further increase in the magnetic field intensity. The high hardness was related to the N/Ti atomic ratio and to a well-pronounced preferred orientation of the(111) planes in the crystallites of the film parallel to the substrate surface. The wear resistance of the Ti N films was significantly improved with the application of the magnetic field, and the lowest wear rate was obtained at magnetic field intensity of 5 m T. Moreover, the wear resistance of the films was related to the hardness H and the H3/E*2 ratio in the manner that a higher H3/E*2 ratio was conducive to the enhancement of the wear resistance.     

Numerical analysis on thickness effect of magnetic thin films on conduction noise absorption in microstrip line

Noise absorbing properties of two kinds of magnetic thin films (one is electrically conductive Co-Zr-O granular thin film and the other is Ni-Zn ferrite thin film with high electrical resistivity) are analyzed by the finite element method (FEM) with various film thicknesses. For the Ni-Zn ferrite film with high electrical resistivity (～2 × 10 ² Ωm), a low reflection parameter (S₁₁) value is predicted, and the value does not significantly change with increased film thickness up to 10 μm. However, the transmission parameter (S₂₁) is reduced with increased film thickness due to increased power absorption by magnetic loss. For the Co-Zr-O thin films with low electrical resistivity (～1.6 × 10^?5 Ωm), however, reflection signal is increased with increased film thickness due to diminished sheet resistance of the thin film. Transmission loss is not very sensitive to the thickness of the conductive film. Large power absorption is, therefore, predicted for conductive film of smaller thickness. It is concluded that film thickness is an important control parameter for the achievement of a highly absorptive thin film with increased electrical conductivity.     

Stress and preferred orientation in nitride-based PVD coatings

Nitride-based coatings are nowadays widely studied both from fundamental and technological point of views due to their unique physical and mechanical properties. Among the binary nitrides, TiN is the most stable thermodynamically and has been widely used due to the combination of its covalent and metal-like characteristics. Coatings produced by Physical Vapor Deposition (PVD) techniques generally exhibit a crystallographic texture, which in turn may strongly affect their properties, such as hardness, wear resistance, or diffusion barrier properties in microelectronic devices. Therefore great efforts have been made in recent years to understand the underlying mechanisms governing texture development in nitride thin films. In particular, the issue of stress build-up during PVD growth and its possible interplay with film preferred orientation is essential to address.We present a brief overview of stress and preferred orientation in nitride-based thin films, either in the form of single-, multi-layered or nanocomposite coatings. X-ray Diffraction (XRD) was used in the standard θ-2θ configuration to study the texture development with film thickness, while the sin²ψ method combined with linear elasticity theory was employed to determine the complete strain/stress state. XRD measurements were made in the framework of the crystallite group method, which is of prime importance in thin films exhibiting a mixed texture, as it enables to selectively measure the elastic strain in a given subset of grains. For PVD films grown with energetic particles, the appropriate modeling requires the use of a triaxial stress tensor, including a hydrostatic stress component to take into account the local distortions induced by growth-defects. This approach enables us to determine the ‘stress-free and defect-free lattice parameter’, a₀, solely linked to chemical effect.Illustrations will be given for fiber-textured TiN and ZrN films deposited on Si substrates, epitaxial TiN layers as well as epitaxial TiN sub-layers in TiN/Cu multilayers grown on (001) MgO single crystal substrates. Ternary TiN-based coatings, either in the form of solid solutions or nanocomposites will be also investigated.     

多弧离子镀负偏压对氮化钛薄膜的影响

目的确定适当的负偏压,提高多弧离子镀氮化钛薄膜的综合性能。方法采用不同的负偏压,在4Cr13不锈钢表面制备Ti N薄膜,探讨偏压对薄膜表面质量、结构、硬度、结合力和摩擦系数的影响。结果负偏压对薄膜表面质量的影响较大:负偏压为0 V时,Ti N薄膜表面凹凸不平,液滴较多;随着负偏压升高,薄膜表面变得光滑,液滴减少并变小,薄膜致密性也得到提高。在不同负偏压下,Ti N薄膜均呈现出在(111)晶面的择优取向,但随着负偏压的增大,这种择优取向逐渐减弱,当负偏压达到400 V时,薄膜在(220)晶面的峰值逐渐增强。随着负偏压从0增至400 V,薄膜的硬度、结合力和耐磨性均先提高,后降低。当负偏压为300 V时,薄膜的硬度和结合力达到最大,分别为2650HV和58 N;摩擦系数和磨损量最小,分别为0.48和0.1065 mm3。结论施加适当的负偏压可以提高薄膜的硬度、结合力、耐磨性等性能,当负偏压为300 V时,薄膜的各项性能达到最佳。     

TiN/Si3N4纳米多层膜硬度对Si3N4层厚敏感性的研究

通过反应磁控溅射制备了一系列不同Si3N4层厚的TiN/Si3N4纳米多层膜,利用X射线衍射仪、高分辨透射电子显微镜、扫描电子显微镜和微力学探针表征了多层膜的微结构和硬度,研究了其硬度随Si3N4层厚微小改变而显著变化的原因.结果表明,在TiN调制层晶体结构的模板作用下,溅射态以非晶存在的Si3N4层在其厚度小于0.7 nm时被强制晶化为NaCl结构的赝晶体,多层膜形成共格外延生长的{111}择优取向超晶格柱状晶,并相应产生硬度显著升高的超硬效应,最高硬度达到38.5GPa.Si3N4随自身层厚进一步的微小增加便转变为非晶态,多层膜的共格生长结构因而受到破坏,其硬度也随之降低.     

Fabrication of highly transparent and superhydrophobic silica-based surface by TEOS/PPG hybrid with adjustment of the pH value

Preparation of superhydrophobic silica-based thin film with high transmittance (T%) in the visible light region by adjusting different pH value of mixing solution has been developed. The hybrid films were coated by the mixing solution which included precursor solution (sol–gel process) and polypropylene glycol (PPG) polymer solution. Rough surfaces were obtained by removing the organic polymer at high temperature and then the hydrophobic groups bonded onto the films were obtained by the reaction with hexamethyldisilazane (HMDS). Characteristic properties of the as-prepared surface of the films were analyzed by contact angle measurement, scanning electron microscopy (SEM), atom force microscopy (AFM), UV–VIS scanning spectrophotometer and Fourier transform infrared (FT-IR) spectrophotometer. The experimental parameters were mainly varied by the pH value (0, 1, 2.3, 6 and 8) of the mixing solution. The result showed that the contact angle of the film was greater than 150° and the transmittance of the film was greater than 90% simultaneously when the pH value of mixing solution was adjusted to 1. In addition, the highly transparent superhydrophobic surfaces was obtained by adding 20 μL acid solution into the mixing solution, which the contact angle of the film was 156.3° as well as the transmittance of the film at the 600 nm visible light was 97.9%.     

Characteristics of TiN thin films grown by ALD using TiCl4 and NH3

Titanium nitride thin film was deposited on a silicon wafer by the Atomic Layer Deposition (ALD) method using TiCl₄ and NH₃ as source chemicals. Nitrogen gas was used for carrying the TiCl₄ and purging the reactants. The gases were introduced into the reaction chamber in the sequence of TiCl₄?N₂?NH₃?N₂ for the saturated surface reaction on the wafer. TiN film was grown with [100] preferred orientation at 350°C, while with [111] preferred orientation at 450°C and higher temperatures. The deposition rate was constant as 0.17 Å/cycle irrespective of deposition temperature, which demonstrates TiN film was grown by the ALD growth mechanism. TiN thin films grown at a temperature higher than 450°C with thickness of 320 Å showed electrical resistivity as low as 72×10^?6 Ωcm.     

Evaluation of nanocrystalline TiN films prepared by arc ion plating

Monolayer and multilayer TiN films were synthesized on a SKD 11 steel sheet by an arc ion plating technique and the correlation between the microstructure and properties of the TiN films was comparatively investigated. The results indicated that the main phase was fcc-TiN, showing a (200) preferred orientation in the film under 2.0 × 10⁻¹ torr N₂ partial pressure, whereas a gradual transition to (111) preferred orientation was observed with decreasing N₂ partial pressure to 1.4 × 10⁻¹ torr. The (200) and (111) textures in the film under an arc current of 80 A were found to be competitive orientations, but the (200) texture became stronger as the arc current was increased. Compared to the optimal monolayer TiN films, the multilayer TiN film possessed high hardness of up to 20.3 ± 1.3 GPa and excellent wear resistance. These features are attributed to the presence of dense microstructures that are mainly composed of TiN phase and are around 1.7 μm to 1.8 μm in thickness.     

TiN颗粒对镁合金微弧氧化过程及膜层性能的影响

目的分析Ti N颗粒在镁合金微弧氧化过程中的作用,并研究其在膜层中对镁合金硬度、耐磨和耐蚀等性能的影响。方法通过在微弧氧化电解液中添加2.7μm Ti N颗粒,并使其充分分散于电解液中,使电解液中Ti N颗粒的质量浓度分别为0、2、4、6 g/L,并控制其他实验参数(如电流密度、频率、占空比和氧化时间)一样的情况下进行实验,通过电子显微镜、涂层厚度测厚仪、显微维氏硬度计、X射线衍射和电化学工作站,分别从膜层的表面形貌、厚度、硬度、相组成及耐蚀性等方面,研究了Ti N颗粒对镁合金微弧氧化膜层性能的影响。结果在微弧氧化电解液中添加Ti N颗粒后,相同电化学参数下制得的微弧氧化膜层变得致密,厚度、硬度有所增加,氧化膜层主要由Mg、MgO、Mg2Zr5O12、Ti N组成。极化曲线显示,加入Ti N颗粒,制备的微弧氧化膜层比未加入Ti N颗粒制得的膜层的腐蚀电流下降了2个数量级。阻抗图谱表明,电阻值增加了1个数量级。结论 Ti N颗粒能够随镁合金的微弧氧化过程进入制得的氧化膜层中,并且能够增加膜层厚度和硬度,使膜层的耐磨、耐蚀性得到提高。     

Microstructural evolution in electroplated Cu thin films

The microstructural evolution of electroplated Cu films (0.89 to 3.0 μm thick) has been studied by texture analysis. Before annealing, the volume fraction of (1 1 1) grains decreases with increasing film thickness, while that of (1 0 0), (1 1 0), and randomly oriented grains increases. Annealing causes a decrease in the 1 1 1 fiber intensity in the thinnest films due to growth of randomly oriented grains and multiple twinning.