Electrochemical behavior of TiN film coated Ti−Nb alloys for dental materials

In order to study the electrochemical behaviors of TiN film coated Ti−Nb alloys for dental materials, Ti containing Nb up to 3, 20, and 40 wt.% was melted by a vacuum furnace and coated with TiN by EB-PVD. the electrochemical behaviors were investigated using a potentiostat in 0.9% NaCl solution and the corrosion surface was observed using SEM and XPS. Ti−3Nb and Ti−20Nb alloys have α+β phase structure. In the case of Ti−40Nb, the microstructure had a coarse β phase. The microstructural changed from equiaxed to acicular and an increase of β-phase in Ti−Nb alloys was observed with increased Nb content. The current density at 300 mV (potential of oral environment) of Ti−40Nb alloy was lower than that of the other alloys in 0.9% NaCl. The pitting corrosion resistance of Ti−40Nb was higher than that of Ti−3Nb and Ti−20Nb alloys in the 0.9% NaCl solution. The corrosion potential and pitting potential of TiN coated Ti alloy increased with increasing Nb content but the current density at 300 mV and the current density at the passive region decreased. The TiN coated Ti−40Nb alloy offers good corrosion resistance for dental implants compared with non-TiN coats alloys.     

Ti/TiN和Ni/TiN多层膜的制备和小载荷下摩擦性能研究

在Si（100）基底上制备了Ti／]r．N和Ni／TiN两种多层膜以及TiN单层膜，利用X射线衍射，WYKO表面形貌仪，俄歇电子能谱等对薄膜进行了分析。分别测试了3种薄膜的粘附力，以及在IoN和naN量级载荷下的摩擦力。研究了相对湿度和载荷等条件对3种薄膜的粘附力和摩擦力的影响。结果表明3种薄膜的粘附力均随着相对湿度的增大而增大，3种薄膜的摩擦力均随着载荷增大而增大。Ti／TiN和Ni／TiN膜在uN和rmN量级载荷下的摩擦力均小于TiN膜。两种多层膜的摩擦性能较TiN膜有所改善。     

奥氏体不锈钢上功能梯度SiC薄膜的制备和性能

用磁控溅射法在奥氏体不锈钢基片上制备了SiC单层膜和Ti/TiN双层膜以及Ti/TiN/SiC功能梯度薄膜。采用XRD和显微硬度计对薄膜的结晶质量和硬度进行表征;用AFM和SEM对薄膜的表面和截面形貌进行了表征。结果表明:Ti/TiN双层膜在氩氮流量比为15∶15时,薄膜的结晶质量最好,硬度最高,达到15.6 GPa,最适合作为钢基SiC薄膜的缓冲层。另外,功能梯度SiC薄膜比SiC单层膜的结晶质量好;不同退火温度下功能梯度SiC薄膜的硬度高于SiC单层膜,同时功能梯度SiC薄膜的表面结晶质量也优于SiC单层膜。     

温度对TiN/Ti多层膜微观结构和氧化行为的影响

研究了TiN/Ti多层膜不同温度下的微观结构和氧化行为.采用阴极弧离子镀沉积的方法制备了19层调制周期为200 nm的TiN/Ti多层膜及相应的TiN单层膜.采用高分辨场发射电子显微镜(HR-FESEM)、光学显微镜和X射线衍射仪(XRD)分别对膜层断面结构、表面形貌和物相进行分析.结果表明,随着加热温度的升高,TiN单层膜在350℃时开始出现局部剥落,550℃出现大范围的剥落,而多层膜未发生剥落;相对TiN单层膜,TiN/Ti多层膜具有层状结构,其抗氧化能力有一定的提高.结合试验结果,讨论了TiN/Ti多层膜和TiN单层膜的工作温度.     

多弧离子镀沉积Ti/TiN多层薄膜的摩擦磨损及电化学性能

软硬交替多层结构的薄膜因其优异的抗摩擦磨损性能和耐腐蚀特性使其在工程领域具有重要的应用价值。利用多弧离子镀在不锈钢和Si(100)表面沉积了Ti N单层薄膜和3种不同Ti/Ti N调制比的多层膜,利用X射线衍射仪(XRD)、扫描电子显微镜(SEM)、CSM摩擦磨损试验机和电化学工作站分别分析了薄膜的结构特征、耐磨损性能和电化学性能。结果表明:多层膜层状结构明显,Ti N相出现(111)面择优取向;Ti与Ti N沉积时间比为1∶5的样品具有较低的摩擦因数(0.26)和磨损率(6.6×10–7 mm3·N–1·m–1);在3.5%Na Cl溶液中,多层膜样品的腐蚀电流密度较不锈钢基体降低了两个数量级,腐蚀电位较不锈钢基体明显提高,表明多层膜可以提高不锈钢基体的耐腐蚀性。     

TiN单层和TiN/Ti(C,N)多层涂层的结构和性能研究

借助XRD、SEM、纳米压痕和划痕仪研究了采用磁控溅射在硬质合金基体上沉积的TiN单层和TiN/Ti(C,N)多层涂层的组织结构和力学性能。研究表明:TiN与TiN/Ti(C,N)多层涂层的晶粒形貌均呈柱状晶结构,而TiN/Ti(C,N)多层涂层形成了TiN、Ti(C,N)交替的调制结构。由于界面强化作用,TiN/Ti(C,N)多层涂层表现出比TiN更高的硬度及与基体更好的结合力。     

Oxidation of TiN and Ti(C,N) thin films deposited on titanium substrate

Single-layered TiN and functionally graded Ti(C,N) coatings were magnetron sputtered to a thickness of about 1 μm, and their oxidation behavior was studied. The Ti(C,N) coating oxidized as fast as the TiN coating, forming TiO₂ as an oxide layer. The nitrogen in the TiN and Ti(C,N) coatings tended to escape from the coating via the TiO₂ layer into the air. The carbon in the Ti(C,N) coating also had strong tendency to escape. Even before the complete oxidation of the coatings, the retained coating layer and the Ti-substrate were strongly enriched with oxygen.     

电弧离子镀方法制备的Ti/TiN多层膜的结构与耐腐蚀性能

采用电弧离子镀技术,通过周期性变换环境气氛,在7075Al合金上制备了Ti/TiN多层膜,并研究调制周期对多层膜的结构组成和腐蚀性能的影响。结果表明:多层膜与铝合金衬底界面结合较好,基本没有孔洞等缺陷。多层膜具有明显的层状特征,层间界面清晰。多层膜中TiN与单层中TiN薄膜有着相同的晶体结构,并存在(111)择优取向,每个调制周期内的TiN层都呈柱状生长。随着调制周期变小,多层膜阳极极化曲线的腐蚀电位增加,交流阻抗谱的阻抗值增大,容抗弧的半径也增大,即膜层的耐腐蚀性增加。多层膜调制周期的减小使得薄膜中含有的层界面增多,而贯穿至衬底表面的针孔等缺陷的数量将减少,这样,腐蚀性介质经过针孔等缺陷与衬底接触的机会变少,这将使薄膜的抗腐蚀能力得到改善。     

钛基 / TiN 涂层接触应力有限元分析

目的研究在接触载荷作用下,钛基/TiN涂层的应力变化规律。方法利用ABAQUS软件建立可靠有限元模型,分析涂层厚度不同的钛基/TiN涂层系统在球压头作用下的接触应力。结果钛基/TiN涂层系统最大Mises应力出现在距表面约0.4a(a为接触半径)处的亚表层或者亚表层附近的界面处。在接触应力和弯曲应力作用下,涂层弯曲变形会影响涂层的径向应力和剪应力分布。结论在接触载荷作用下,涂层内存在接触应力和自身弯曲两种应力作用。分析结果有利于理解钛基Ti N涂层的失效机理。     

Pulsed DC plasma enhanced chemical vapor deposited TiN/Ti(C,N) multilayer coatings

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阴极电弧离子沉积TiN／Ti镀层腐蚀特性

采用电化学线性极化、交流阻抗谱技术研究了不同基片偏压上阴极电弧沉积TiN/Ti镀层在50×10-6g/gCl-溶液中的腐蚀行为,并对镀层腐蚀的机理进行了探讨。结果表明:基片偏压–400V时,镀层耐蚀性能好;镀层表面的针孔是诱发镀层和基材体系发生点蚀、电偶腐蚀的主要缺陷。     

The corrosion behavior of TiN coated and uncoated incoloy 800 alloy

Incoloy alloy 800 is used in a variety of applications in industry as well as in domestic appliances for sheeting on electric heating elements. The composition of the alloy enables it to resist deterioration in many corrosive environments. However, resistance of the alloy to corrosion in aqueous media needs to be further examined. The present study examines the corrosion properties of Incoloy 800 alloy of both coated and uncoated workpieces obtained in a 0.1N H₂SO₄ + 0.05N NaCl solution. TiN coating is achieved using a physical vapor deposition (PVD) technique while corrosion tests are carried out using electrochemical polarization methods. Moreover, in order to examine the influence of hydrogen diffusion, reduction of hydrogen at the Incoloy 800 surface is carried out in a solution of 0.1N HNO₃ + 1 g/L thiourea. Tensile tests are conducted on the workpieces to determine the influence of hydrogen embrittlement on the resulting mechanical properties of the substrate. To examine the pit formation and stress induced microcracking, scanning electron microscope (SEM) analysis is carried out. The results show that the corrosion resistance of the alloy improves after TiN coating. In addition, no specific pattern or differentiation on the pit geometry is observed. The pitting rate and its size reduce considerably for TiN coated workpieces.     

硬质颗粒重复冲击TiN/Ti涂层损伤分析

航空发动机压气机叶片表面制备硬质涂层可显著提高其抗砂尘冲蚀性能,但砂粒高角度冲击对涂层损伤严重,易出现脆性裂纹。采用受控动能型重复冲击设备模拟硬质颗粒对涂层的高角度冲击,研究调制比、层数结构对TiN/Ti涂层冲击损伤的影响,并根据涂层损伤特征、冲击力学响应以及应力分布分析涂层的破坏机理。结果表明,TiN/Ti涂层出现剥落和圆周裂纹;硬质层内部、硬质层与结合层/过渡层界面存在高的应力梯度,而冲击坑点边缘硬质层上表层受到拉应力且由于材料堆起,在重复冲击下将导致涂层的疲劳剥落和圆周疲劳裂纹。调制比、层数显著影响涂层冲击响应过程,其中不同调制比的2层涂层,调制比为3:1的抗冲击性能较好;调制比为9:1的不同层数涂层,4层结构的抗冲击性能较好。     

钛合金表面百微米级Ti/TiN多层复合涂层性能研究

目的提高TiN硬质涂层的厚度及各项力学性能。方法采用等离子增强PVD技术在钛合金(TC4)基体表面制备多层复合Ti/TiN涂层,对涂层进行扫描电镜(SEM)分析,采用划痕法表征涂层的结合强度,用维氏显微硬度计测试涂层的显微硬度,利用销盘式摩擦磨损试验仪评价涂层的摩擦磨损性能。结果制备的多层复合Ti/TiN涂层厚度最高可达100μm,且未发生剥落等失效,结合强度相对于单层TiN提高了近3倍。由于Ti、TiN的多层复合调制作用,制备的Ti/TiN显微硬度测试表明复合涂层的显微硬度高达2700 HV0.025,同时,涂层在原有耐磨性能优良的基础上具备自润滑减摩作用,经过近20 000 m的磨损测试,复合涂层的摩擦系数低至0.25左右,且未完全失效。结论多层复合结构能够有效提高TiN硬质涂层的厚度,制备的Ti/TiN多层复合涂层的各项力学性能显著提高。     

Surface characteristics of HA coated Ti-Hf binary alloys after nanotube formation

Ti-Hf binary alloys contained 10%, 20%, 30% and 40% (mass fraction)Hf were manufactured in the vacuum furnace system. And then, specimens were homogenized for 24 h at 1 000 °C in argon atmosphere. The formation of oxide nanotubes was conducted by anodic oxidation on the Ti-Hf alloy in 1 mol/L H₃PO₄ electrolytes containing small amounts of NaF at room temperature. The hydroxyapatite (HA) coating made of tooth ash prepared by electron-beam physical vapor deposition (EB-PVD) method. The corrosion behaviors of the specimens were examined through potentiodynamic test in 0.9% NaCl solution by potentiostat. The microstructures of the alloys were examined by field emission scanning electron microscopy (FE-SEM) and x-ray diffractometer (XRD). It was observed that the lamellar structure translated to needle-like structure with Hf contents. Nanotube formed and HA coated Ti-xHf alloys had a good corrosion resistance.     

航空发动机叶片 TiN / Ti 涂层基体冲蚀响应数值模拟

目的研究Ti N/Ti涂层结构变化对TC4钛合金基体冲击塑性应变的影响。方法采用有限元分析软件ABAQUS建立球形Al2O3颗粒冲击覆有Ti N/Ti涂层TC4基体的二维轴对称模型,分析涂层硬质层厚度、硬质层层数对基体在冲击过程中的等效塑性应变的影响规律。结果对于无涂层的基体,其冲击塑性应变仅发生在冲击的加载阶段,冲击塑性应变分为加载及卸载两个阶段,加载阶段基体的塑性应变由球形颗粒的冲击产生,卸载阶段基体的塑性应变由涂层硬质层的回弹产生。对于单层结构涂层,当硬质层厚度低于12μm时,随着硬质层厚度的增加,基体的塑性应变较大且呈振荡变化;当硬质层厚度超过12μm时,随着硬质层厚度的增加,基体的塑性应变减小。对于多层结构涂层,当硬质层的厚度不变,增加涂层硬质层层数使得基体的塑性应变减小。结论有限元可以模拟分析Ti N/Ti涂层结构对TC4钛合金冲蚀性能影响规律,优化Ti N/Ti抗冲蚀涂层的结构设计参数,对抗冲蚀涂层的结构设计及其进一步研究具有指导意义。     

Fretting wear behavior of Ti/TiN multilayer film on uranium surface under various displacement amplitudes

Ti/TiN multilayer film was deposited on uranium surface by arc ion plating technique to improve fretting wear behavior. The morphology, structure and element distribution of the film were measured by scanning electric microscopy (SEM), X-ray diffractometry (XRD) and Auger electron spectroscopy (AES). Fretting wear tests of uranium and Ti/TiN multilayer film were carried out using pin-on-disc configuration. The fretting tests of uranium and Ti/TiN multilayer film were carried out under normal load of 20 N and various displacement amplitudes ranging from 5 to 100 μm. With the increase of the displacement amplitude, the fretting changed from partial slip regime (PSR) to slip regime (SR). The coefficient of friction (COF) increased with the increase of displacement amplitude. The results indicated that the displacement amplitude had a strong effect on fretting wear behavior of the film. The damage of the film was very slight when the displacement amplitude was below 20 μm. The observations indicated that the delamination was the main wear mechanism of Ti/TiN multilayer film in PSR. The main wear mechanism of Ti/TiN multilayer film in SR was delamination and abrasive wear.     

The electrochemical corrosion behavior of TiN and (Ti,Al)N coatings in acid and salt solution

In this study, the corrosion properties of TiN and (Ti,Al)N coatings fabricated by Hollow Cathode Ionic Plating (HCIP) were studied by electrochemical techniques such as electrochemical impedance spectroscopy (EIS) measurement and potentiodynamic measurement in acid and salt solution. It was found that both coatings showed an excellent corrosion resistance in acid and salt solutions at the beginning of long-term immersing test. The corrosion resistance of TiN coating deteriorated rapidly after nearly 100 h immersion in both acid and salt solutions. In the contrast, the corrosion rate of (Ti,Al)N coating decreased a little and then kept at a stable value. For the TiN coating, the corrosion initiated from pinholes and the underlying corrosion was very similar to pitting corrosion. With the addition of aluminum to the TiN coating, the corrosion resistance was improved, especially in salt solution. The test results demonstrated that the (Ti,Al)N coating seemed to posses certain self-repairing function. The corrosion mechanism took the form of denudation corrosion, owing to deterioration of the adhesion of the coating.     

Effects of Ti/TiN multilayer on corrosion resistance of nickel-titanium orthodontic brackets in artificial saliva

The effects of multilayered Ti/TiN or single-layered TiN films deposited by pulse-biased arc ion plating (PBAIP) on the corrosion behavior of NiTi orthodontic brackets in artificial saliva are investigated. The multilayered Ti/TiN coating is found to exhibit a greater free corrosion potential, much lower passive current density, and no breakdown up to 1.5 V. Moreover, electrochemical impedance spectroscopy (EIS) results indicate that the multilayered Ti/TiN coating has a larger impedance and lower porosity which is believed to be responsible for the exceedingly low metal ion release rate during 720 h exposure in the test solution. Visual inspection of the surfaces reveals different corrosion processes for the TiN and multilayered Ti/TiN coatings.     

多层结构对Ti/TiN涂层性能的影响

以TiN、TiAlN为主的过渡族金属氮化物硬质涂层以其较高的表面硬度、良好的耐磨以及抗高温氧化性能,被广泛应用于材料表面防护涂层。然而,涂层内部积聚的高内应力却容易易引发起涂层与基体的结合力问题。利用PVD技术很难在材料表面制备出厚度超过10微米的TiN或TiAlN涂层。多层复合结构能够有效控制涂层中的应力分布,从而使得其成为获得较厚硬质涂层的一种有效方法。本文在TC4合金以及Si（100）基体上利用等离子增强离子镀技术制备了具有不同复合层数的多层Ti/TiN涂层,并研究了复合层数对涂层力学性能的影响。结果表明,随着复合层数的增加,涂层的各项力学性能得到了显著强化。涂层的显微硬度高达2750HV,厚度大于50微米,且具有较好的韧性。涂层的韧性与显微硬度成正比例关系。同时,48层复合结构的Ti/TiN涂层具有低于0.35的摩擦系数以及最佳的抗磨损性能。然而,随着复合层数的进一步增加,涂层与基体的界面显著弱化了涂层的结合强度。