钇和铈离子注入纯锆的腐蚀行为研究

为了研究铈,钇离子注入对纯锆耐蚀性的影响,纯锆样品用MEVVA源以40 kV注入1×1016 ions/cm2至1×1017 ions/cm2剂量的钇和铈,注入最高温度约为150℃.用X光电子谱仪(XPS)分析注入表层元素的价态;在1 mol/L硫酸溶液中3次极化测量来研究注入样品的耐蚀性.对于钇离子注入,当注入剂量大于5×1016 ions/cm2时,注入样品的耐蚀性显著提高.用掠角X射线衍射(GAXRD)研究氧化膜中由于铈离子注入发生的相转移.三次极化测量表明注铈样品与空白样品相比,耐蚀性下降许多.最后分别对注入钇和铈样品的腐蚀行为机理进行了探讨.     

锆离子轰击对纯锆腐蚀行为的影响

为了研究自离子轰击对纯锆耐蚀性的影响,用MEVVA源对纯锫样品进行了1×1015至2×1017ions/cm2的自离子轰击,注入温度为170℃,加速电压为50 kV.用X射线光电子谱(XPS)对注入表面各元素进行价态分析;用Auger电子能谱(AES)分析氧化膜厚度.三次极化测量用来评价轰击样品在1 mol/L H2SO4溶液中的耐蚀性.用掠射X射线衍射(GAXRD)分析自离子轰击造成的氧化膜相转变.研究表明: 5×1016 Zr ions/cm2自离子轰击样品的耐蚀性最好.对自离子轰击纯锆的腐蚀行为机理进行了讨论.     

钼离子注入对纯锆耐蚀性的影响

使用MEVVA源对纯锆表面注入1×1016 ions/cm2至5×1017 ions/cm2剂量的钼离子,研究离子注入后其在水溶液中耐蚀性;注入时的最高温度为160℃,加速电压为40 kV。用X光电子谱(XPS)分析表面元素价态;3次极化扫描评价注入样品在0.5 mol/L硫酸水溶液中的耐蚀性,并对3次极化后的样品进行扫描电镜(SEM)观察。实验表明:随着钼离子注入剂量的增大,注入样品的耐蚀性反而下降。剂量越大,耐蚀性下降越多。注入样品的自然腐蚀电位与未注入纯锆相比发生了正移,总的趋势是随着剂量的加大,自然腐蚀电位越正。最后讨论了钼离子注入纯锆后耐蚀性下降的原因。     

高能氪离子轰击对纯锆耐蚀性的影响

为了研究高能氪离子轰击对纯锆水溶液中耐蚀性能的影响,纯锆样品用LC-4型离子注入机在40℃温度下进行高能氪离子轰击,注入剂量从1×1015ions/cm2到3×1016ions/cm2,注入能量为300keV。用X-射线光电子谱(XPS)分析注入表层元素价态,俄歇电子谱(AES)测试氧化膜的深度分布,用透射电镜(TEM)观察轰击样品的形貌和结构转变,轰击样品在1N硫酸溶液中的耐蚀性能用动电位极化测量曲线表征。结果表明:高能氪离子轰击样品后其耐蚀性能大大降低,轰击剂量越大,耐蚀性越差。最后讨论了辐照腐蚀的机理。     

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 利用磁过滤阴极电弧镀分别在硬质合金和高速钢基体上沉积厚度约2～3μm的TiN薄膜,并用MEVVA源离子注入装置对TiN薄膜注入金属离子V+和Nb+。应用北京同步辐射装置（BSRF）的同步辐射光源,采用掠入射X射线衍射（GIXRD）的方法对TiN薄膜表面离子注入层的微观结构进行了分析研究。结果表明：未经过离子注入的TiN薄膜均存在特定方向的择优取向,而较小剂量(1×10ˇ17ions/cm2)的离子注入可以使晶粒细化、择优取向减弱或改变;当离子注入的剂量达到5×10ˇ17ions/cm2时,TiN薄膜表面离子注入层被非晶化。结合透射电镜的研究结果,观察到TiN薄膜表面非晶层的厚度约为50～100nm,并简要地讨论了离子注入过程对微观结构的影响机制。     

镧离子注入对纯锆抗高温氧化性能的影响

对纯锆表面注入了1×10~(16)ions/cm~2～1×10~(17)ions/cm~2的镧离子,并在500℃条件下进行了空气氧化增重研究。用XPS分析了注入的镧、锆的价态;用AES分析了镧锆氧三元素的深度分布;用0.3°小角X光掠射(GAXRD)分析了高温氧化时氧化锆的相转变。结果表明,纯锆表面注入La离子后,其抗高温氧化性能显著提高,且注入剂量越大效果越强,注入氧化膜以La_2O_3和ZrO_22种形式存在;由于La离子的注入,促使形成大量四方相氧化锆(t-ZrO_2),而且减少四方相氧化锆(t-ZrO_2)向单斜相氧化锆(m-ZrO_2)的转变,这是纯锆氧化速率降低的根本原因。     

Ag离子注入Ti6Al4V合金抗Hank’s溶液腐蚀性能研究

采用注入不同剂量5×1016, 1×1017, 5×1017和9×1017ions/cm2,加速电压30 kV对Ti6Al4V合金进行Ag离子注入表面改性。使用动电位极化曲线研究Ag离子注入前后Ti6Al4V合金抗Hank’s溶液腐蚀性能,利用小角掠射X射线衍射技术研究Ag离子注入前后Ti6Al4V合金表面物相组成,用X射线光电子能谱技术分析离子注入合金表面和腐蚀样品表面元素存在的化合态。结果表明,Ag离子注入提高了合金抗Hank’s溶液腐蚀性能,腐蚀电流密度随Ag离子注入剂量的增加稍有变化。离子注入Ti6Al4V合金表面的氧化物腐蚀阻挡层、离子注入表面合金层和表面生成的Ag和TiAg有利于合金抗Hank’s溶液腐蚀性能的改善     

Ti离子注入H13钢表面改性研究

利用MEVVA源强流离子注入机将Ti离子注入到H13钢表面,注入剂量和离子能量分别为0.5×1017~5.0×1017ions/cm2和105keV。利用TR IM2003程序模拟计算饱和注入剂量;通过显微硬度仪、磨损试验机、电化学测试系统和扫描电镜测试了注入前后H13钢的表面硬度、磨损性能、摩擦系数和耐蚀性。利用SEM、AES、XPS和EDX等分析手段对注入前后的材料表面形貌、注入元素的化学价态及浓度分布等进行分析。借助XPS考察了注入表面层钛元素的化学状态。结果表明,Ti离子注入显著提高了H13钢的表面硬度、耐磨性和耐蚀性,减轻了磨粒磨损;减轻了表面层铁元素的氧化。通过所测主要性能可知,利用钛离子注入改善H13钢较为经济有效的注入参数分别为1.0×1017ions/cm2和105keV。     

Ti-2Al-2.5Zr合金N+离子注入表面XPS和XRD分析

Ti-2Al-2.5Zr合金中注入能量为75keV的N+离子, 注入剂量为3×1017/cm2和8×1017/cm2, 注入过程样品的温度低于200℃. N+离子在Ti-2Al-2.5Zr合金中的射程借助TRIM 96程序计算为1222. 注入后的样品用X射线衍射方法(XRD)以及光电子能谱方法(XPS)进行分析. XRD衍射谱表明有新相生成, 经分析为TiN和TiO2, 但这些新相的峰非常微弱, 很难区分. XPS宽程扫描谱表明注入后样品表面主要为Ti, C, N和O. XPS关于Ti2p和N1s窄程扫描谱表明N+离子注入后在合金表面确实形成了TiN和TiO2.     

氮离子注入TiNi形状记忆合金表面改性

采用1×1016ions/cm2的注入剂量对TiNi形状记忆合金进行氮离子注入,注入加速电压为50 keV。采用X射线衍射和X射线光电子能谱对氮离子注入前后TiNi形状记忆合金表面的物相以及化学成分进行了分析。结果表明,氮离子注入前后TiNi合金表面都被氧化。氮离子注入前TiNi形状记忆合金表面存在少量TiO2、Ti3O5和Ti2O3。氮离子注入后的TiNi形状记忆合金表面有TiN新相生成,且在氮离子注入后的TiNi形状记忆合金表面还存在少量TiO2、Ti3O5。     

EFFECT OF CERIUM ION IMPLANTATION ON THE AQUEOUS CORROSION BEHAVIOR OF ZIRCONIUM

1.IntroductionBecause of the low thermal neutron capture cross section, adequate mechanical properties and good corrosion resistance, zirconium and its alloys are often specified for engineering in the nuclear industry. For example, it can serve as fuel cladding and core structure material. However, with the concept of high burn-up developing, enhancement of performance of zirconium and its alloys increasingly required. It is well known that ion beam surface processing (IBP) techniques can s…     

Surface analysis and corrosion behavior of zirconium samples implanted with yttrium and lanthanum

Zirconium specimens were implanted with yttrium and lanthanum ions with a fluence ranging from 1×10¹⁶ to 1×10¹⁷ ions/cm² at approx. 130 °C, using a metal vapor vacuum arc source at an extraction voltage of 40 kV. The surfaces of the implanted samples were then analysed. The valence states of elements in implanted surface layer were analysed by X-ray photoelectron spectroscopy (XPS), which showed that yttrium existed in the form of Y₂O₃, and lanthanum existed in the form of La₂O₃. Depth distributions of elements in the implanted surface of samples were obtained by Auger electron spectroscopy (AES), which showed that the oxide film of zirconium substrate became thicker with increasing implantation fluence, the thicknesses of the oxide films reached the maximum approximately to the fluence of 1×10¹⁷ ions/cm². Rutherford back-scattering indicates that a profile of La appears in Zr around the depth of 30 nm, which also indicates that a serious sputtering occurred during the (La+Y) 1×10¹⁷ ions/cm² implantation. The potentiodynamic polarization technique was employed to evaluate the aqueous corrosion resistance of the implanted-zirconium samples in 0.6 M H₂SO₄. It was found that a significant improvement was achieved in the aqueous corrosion resistance of zirconium compared with that of as-received zirconium when the fluence is smaller than 5×10¹⁶ (Y+La)/cm². The mechanism of the corrosion behavior of the implanted-zirconium samples was discussed.     

Effect of Sn ion implantation on electrochemical behavior of zircaloy-4

In order to study the effect of tin ion implantation on the aqueous corrosion behavior of zircaloy-4, specimens were implanted by tin ions with a dose range from 1×10¹⁶ to 5×10¹⁷ ions/cm² at an extracted voltage of 40 kV. The valence and element penetration distribution of the surface layer were analyzed by X-ray photoelectron spectroscopy (XPS) and auger electron spectroscopy (AES), respectively. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) were used to examine the micro-morphology and microstructure of tin-implanted samples. When the dose is 5×10¹⁶ ions/cm² or higher, a large number of small tin balls are produced in the implanted surface. The potentiodynamic polarization measurement was employed to evaluate the aqueous corrosion resistance of zircaloy-4 in a 0.5 M H₂SO₄ solution. It was found that a significant improvement was achieved in the aqueous corrosion behavior of zircaloy-4 implanted with tin when the dose is 1×10¹⁶ ions/cm². When the dose is higher than 1×10¹⁶ ions/cm², the corrosion resistance of zircaloy-4 implanted with tin ions decreased compared with that of the as-received zircaloy-4. Finally, the mechanism of the corrosion behavior of the tin-implanted zircaloy-4 is discussed.     

Improvement of tribological behavior of a Ti-Al-V alloy by nitrogen ion implantation

The tribological properties especially wear and hardness of a Ti-Al-V alloy with nitrogen implantation (energy 60 keV) were investigated. The implantation was carried out at fluences range from 1×1016 to 4×1017 ions/cm2. Glancing angle X-ray diffraction (GAXRD) and X-ray photoelectron spectroscopy (XPS) analyses were performed to obtain surface characterization of the implanted sample. The unimplanted and implanted samples were also annealed at 600 ℃ in order to understand the influence of annealing on the tribological properties of Ti-Al-V. The hardness shows significant improvement at the higher fluence. After annealing at 600 ℃, the friction coefficient exhibits a relative decrease for the nitrogen-implanted samples. In addition, the wear rates of the implanted samples exhibits a great decrease after annealing at 600 ℃. Nature of the surface and reason for the variation and improvement in wear resistance were discussed in detail.     

离子注入对LaFe11.6Si1.4合金的缓蚀及其机理研究

目的通过表面Cr离子注入在LaFe_(11.6)Si_(1.4)合金表面生成一层具有耐蚀作用的保护层,从而提高合金的耐腐蚀性能。方法采用表面离子注入法,分别在注入电压为20、30、40 k V,注入计量为5×10~(16)、10×10~(16)、50×10~(16) ions/cm~2的条件下注入Cr离子。利用扫描电子显微镜及X-射线衍仪对合金的表面形貌、组织结构及成分进行了分析,通过电化学方法对合金表面离子注入后的耐腐蚀性进行了研究。结果当Cr离子的注入电压为40 k V,注入剂量为5×10~(16)、1×10~(17)、5×10~(17) ions/cm~2时,合金的开路电位分别是-0.585、-0.584、-0.57V(vs.SCE)。当Cr离子的注入剂量为5×10~(17) ions/cm2,注入电压为20、30、40 k V时,合金的开路电位分别是-0.63、-0.61、-0.57 V(vs.SCE)。可以看到,随着Cr离子注入计量和注入电压的增加,合金表面的腐蚀电位正向移动,耐腐蚀性提高。结论 Cr离子注入能够显著提高合金的耐腐蚀性,分析认为主要是由于合金表面生成了一层具有耐腐蚀性能的Cr_2O_3钝化层。此外,由于注入离子的轰击导致表面La(Fe,Si)13相分解生成α-Fe,也提高了合金的电极电位,增强了耐腐蚀性。     

聚苯醚金属离子注入改性层的硬度和磨擦学性能

为研究离子注入技术对聚苯醚（PPO）的表面硬度和耐磨性的提高效果,分别将3种剂量（2×1015 cm－2、1×1016 cm－2和1×1017 cm－2）的Al、Ti 、Fe离子注入PPO。纳米硬度测量显示,1×1016 cm－2 Ti离子注入PPO后其硬度由0.369 GPa增至1.433 GPa,离子注入使PPO表面形成一层交联层,导致其硬度提高。磨损实验表明,3种离子注入后均可使PPO的耐磨性提高,摩擦因数下降;其中1×1016 cm－2 Ti离子注入PPO的磨损体积降为原来的0.4%,摩擦因数下降了40％。红外光谱分析表明,离子注入后PPO表面形成羟基和羰基等新的基团,羟基的形成主要与表面微量吸水有关。电子自旋共振(ESR)分析显示离子注入可以形成自由基,离子注入诱发交联的方式主要为自由基交联。     

Corrosion resistance properties of AZ31 magnesium alloy after Ti ion implantation

Magnesium alloys have a wide range of applications in industry; however, their corrosion resistance, wear resistance, and hardness are rather poor, which limit their applications. Ti ion was implanted into the AZ31 magnesium alloy surface by metal vapor vacuum arc (MEVVA) implanter. This metal arc ion source has a broad beam and high current capabilities. The implantation energy was fixed at 45 keV and the dose was at 9 × 1017 cm?2. Through ion implantation, Ti ion implantation layer with approximately 900 nm in thickness was directly formed on the surface of AZ31 magnesium alloy, by which its surface property greatly improved. The chemical states of some typical elements of the ion implantation layer were analyzed by means of X-ray photoelectron spectroscopy (XPS), while the cross sectional morphology of the ion im-plantation layer and the phase structure were observed by means of scanning electron microscopy (SEM) and X-ray diffraction (XRD). The property of corrosion resistance of the Ti ion implanted layer was studied by the CS300P electrochemistry corrosion workstation in 3.5% NaCl solution. The results showed that the property of corrosion resistance was enhanced remarkably, while the corrosion velocity was obviously slowed down.     

In vitro corrosion evaluation of nitrogen ion implanted titanium in simulated body fluid

Surface modification of commercially pure (CP) titanium was attempted by nitrogen ion implantation to investigate corrosion resistance in simulated body fluid. Nitrogen ion was implanted at 70 keV energy for different doses ranging from 5 × 10¹⁵ to 2.5 × 10¹⁷ ions/cm². In Vitro Open Circuit Potential (OCP-time measurements and cyclic polarization studies were carried out to evaluate the corrosion resistance of the implanted specimens with reference to the unimplanted one. Specimens implanted at 4 × 10¹⁶ and 7 × 10¹⁶ ions/cm² showed optimum corrosion resistance, and implantation beyond this dose deteriorated the corrosion resistance. Gracing Incidence X-ray diffraction (GIXD) was employed on implanted specimens to understand the phases formed with increasing doses. The results of the present investigation indicated that nitrogen ion implantation can be used as a viable method for improving corrosion resistance of titanium. Nature of the surface and reason for the variation and improvement in corrosion resistance are discussed in detail.