D.Q.Tang
,
Y. Wang
,
E.Y.Jiang
,
C.Zhao and F.L.Sun Department of Applied Physics
,
Tianjin University
,
Tianjin 300072
,
China
金属学报(英文版)
CN x films were made by a facing targets sputtering ( FTS) systemon the Si(100) substrate under different N 2 partial pressure. XRD, XPS, FTIR and Raman Spectroscopy( RS) were measured to investigate the structure and the binding state of the film. The films are amorphous and the N/C increases with the N 2 partial pressure increasing and reaches 0 46 when the N 2 pressure is 100%. The N incorporated C forms N sp 2C and N sp 3C mainly and there is a small amount of C≡N.
关键词:
Corrosion
The influence of applied potential on the cavitation erosion (CE) behavior of Type 316L (UNS S31603) stainless steel in 0.05 mol/L sulfuric acid (H2SO4) solution was investigated by using a magnetostrictive-driven CE apparatus. Eight different potentials were selected according to the dynamic polarization curve. Mass loss at different potentials was measured after the tests. Electrochemical impedance spectroscopy (EIS) measurement at different potentials was carried out during each experiment at different intervals. The morphologies of the specimen surfaces were observed using scanning electron microscopy (SEM), and the roughness (Ra) of each surface was measured using a profilometer. The mass-loss results showed that cathodic protection could significantly decrease the CE rate, and the more negative the cathodic potential was, the higher protection efficiency was and the maximum cathodic protection efficiency could be more than 80%. The influence of applied anodic potential on the CE behavior could be classified into three types. First, the CE rate at potentials close to the corrosion potential was almost the same as that at the corrosion potential. The CE rate then decreased a lot in the passive region, and the protection efficiency (89.7%) was even a little higher than that of cathodic protection. Finally, the CE rate increased at higher passive potentials and became very high in the transpassive region. Extremely large electrochemical impedance was shown in the EIS plot at an applied potential of 0.2 V where the best anodic protection was achieved. The SEM, roughness, and EIS results were well in accordance with that of mass loss and provided more detailed information on the CE behavior. A model to describe the effect of the applied potential on CE was proposed.
关键词:
applied potential;cavitation erosion;electrochemical impedance;spectroscopy;model;roughness;sulfuric acid;Type 316L stainless steel;electrochemical impedance spectroscopy;corrosion behavior;slurry;coatings;alloy;wear
Corrosion Engineering Science and Technology
In order to explore the relationships between rare earth elements existing in oxides and growth rate and adhesion of oxide scales, CeO2 thin films were prepared on Fe-20Cr alloys after preoxidation at 1000 degrees C; subsequent isothermal and cyclic oxidation was carried out, and the oxide adhesion was determined by using the tensile pull test. The results demonstrated that similar to the effects of CeO2 on the as polished Fe-20Cr alloy, the application of CeO2 to the preformed oxides could decrease the subsequent oxidation rate, improve the cyclic oxidation resistance of the alloy and raise the adhesion strength of the oxide scales. These beneficial effects of the applied CeO2 decreased with increasing pre- oxidation time. The fact that virtually none of CeO2 applied on the preoxidised preformed layer reached the metal/oxide interface suggests that the 'sulphur trapping effect', through which CeO2 may act, is minimal in the present system.
关键词:
rare earth elements;oxidation;oxide adhesion;CeO2;Fe-20Cr alloy;high-temperature oxidation;chromia-forming alloys;stainless-steel;segregation;cr2o3;cr
康健
,
叶超
,
辛煜
,
程珊华
,
宁兆元
功能材料
采用电子回旋共振等离子体化学气相沉积(ECR-CVD)技术,用苯和三氟甲烷混合气体,制备了氟化非晶碳膜(a-C:F).用红外吸收光谱(FTIR)和X射线光电子能谱(XPS)分析了a-C:F薄膜的结构.FTIR结果表明,氟主要以C-F、CF2的形式成键形成a-C:F薄膜;XPS结果进一步证明a-C:F膜中存在C-F、CF2键,获得了与FTIR相一致的结果.
关键词:
a-C:F薄膜
,
ECR-CVD
,
键结构
肖剑荣
,
徐慧
,
李幼真
,
刘雄飞
,
马松山
,
简献忠
中国有色金属学报
使用CF4和CH4为源气体,利用射频等离子体增强化学气相沉积法,制备了a-C:F:H薄膜样品.采用拉曼光谱仪、傅里叶变换红外光谱仪、X射线光电子能谱仪(XPS)对薄膜的结构进行了测试和分析.研究发现:该膜呈空间网状结构,膜内碳与氟、氢的结合主要以sp3形式存在,而sp2形式的含量相对较少;在薄膜内主要含有C-Fx(x=1,2,3)、C-C、C-H2、C-H3等以及不饱和C=C化学键;同时,薄膜中C-C-F键的含量比C-C-F2键的含量要高.在不同功率下沉积的薄膜,其化学键结构明显不同.
关键词:
a-C:F:H薄膜
,
等离子体增强化学气相沉积
,
低介电常数
,
化学键
QIAO Lijie LIU Rui XIAO Jimei University of Science and Technology Beijing
,
Beijing
,
China
金属学报(英文版)
The effects of stress components on nucleation sites and propagation directions of stress cor- rosion cracks in brass were investigated with specimens under mode Ⅱ and mode Ⅲ loadings. The results indicated that under mode Ⅱ loading,stress corrosion cracks nucleated on the site with maximum normal stress component and propagated along the plane perpendieular to the maximum normal stress,under mode Ⅲ loading,the stress corrosion crack was not evident on the 45°plane due to the general corrosion in aqueous solution with high NH_4OH concentra- tion,while stress corroded in aqueous solution with low NH_4OH concentration, numerous cracks with spacings of 10—150μm were found on the 45°plane with maximum normal stress and no stress corrosion cracks was observed on the plane with maximum shear stress.
关键词:
stress corrosion cracking
,
null
,
null
,
null
钟胜奎
,
尹周澜
,
王志兴
,
郭华军
,
李新海
,
陈启元
稀有金属材料与工程
利用碳热还原法,通过两步反应合成了LiVPO4F/C复合正极材料.主要研究了球磨、碳含量和电解液对样品结构和电化学性能的影响.结果表明:球磨2 h在750℃下能合成纯的LiVPO4F产品,剩余碳的存在使LiVPO4F的粒径减小且分布较为均匀,同时提高了颗粒之间的导电性.对样品进行电化学性能测试表明,含碳量为1.83%的LiVPO4F/C的样品比容量和循环性能都得到显著改善;合适的电解液可以明显提高样品LiVPO4F的电化学性能.含碳量为1.83%的LiVPO4F/C的复合材料以1 mol.L-1LiPF6/EC+EMC+DMC(体积比1∶1∶1)为电解液,在0.2 C的倍率下放电时,其首次放电容量为119 mAh.g-1,放电平台在4.2 V左右(vs.Li),循环30次后比容量为89 mAh.g-1.
关键词:
锂离子电池
,
正极材料
,
LiVPO4F/C
,
碳热还原法
刘雄飞
,
肖剑荣
,
李幼真
,
张云芳
材料导报
氟化非晶碳(a-C:F)薄膜是一种电、光学新材料.介绍了它的制备方法,对其制备工艺作了较全面的探讨;分析了该膜制备方法和工艺参数对薄膜组分及化学键结构的影响;研究了该膜的电学、光学、热学、力学等物理性质及其在相关方面的应用,并对该膜的物理性质与制备工艺参数的关联作了详细的论述;指出介电常数和热稳定性的矛盾是阻碍该膜实用化的主要原因.
关键词:
氟化非晶碳薄膜
,
介电常数
,
光学带隙
,
热稳定性
,
化学气相沉积
于宏伟
,
韩卫荣
,
刘磊
,
顾丹丹
,
牟微
,
陈宁
材料导报
doi:10.11896/j.issn.1005-023X.2014.24.022
在303～393 K的温度范围内,测定聚四氟乙烯F-C-F伸缩振动模式(WCF2)的一维红外光谱.研究发现:1220 cm-1的红外吸收峰归属于聚四氟乙烯F-C-F不对称伸缩振动模式(VasCF2),而1150 cm-1的红外吸收峰则归属于聚四氟乙烯F-C-F对称伸缩振动模式(VsCF2).进一步研究了聚四氟乙烯VCF2的二阶导数红外光谱、四阶导数红外光谱,发现聚四氟乙烯VasCF2在1210 cm-1和1260 cm-1处裂分为双峰;而聚四氟乙烯VsCF2则在1145 cm-1、1155cm-1和1175 cm-1裂分为3个吸收峰.最后研究了聚四氟乙烯二维红外光谱,考察了温度对于聚四氟乙烯VCF2吸收强度变化的影响.研究发现:随着测定温度的升高,聚四氟乙烯VCF2红外吸收强度变化快慢的顺序为:1145 cm-1＞1210 cm-1＞ 1155 cm-1＞ 1175 cm-1＞ 1260 cm-1.本项研究拓展了二维红外光谱在聚四氟乙烯热变性方面的研究范围.
关键词:
一维红外光谱
,
二阶导数红外光谱
,
四阶导数红外光谱
,
二维红外光谱
,
聚四氟乙烯
