材料工程  2016, Vol. 44 Issue (5): 72-78   PDF    
http://dx.doi.org/10.11868/j.issn.1001-4381.2016.05.012
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文章信息

王国材, 肖小波, 陈艳萍, 王晨
WANG Guo-cai, XIAO Xiao-bo, CHEN Yan-ping, WANG Chen
Ce68Al10Cu20Nb2大块非晶表面钝化膜的研究
Passive Film Formed on Ce68Al10Cu20Nb2 Bulk Amorphous Alloy
材料工程, 2016, 44(5): 72-78
Journal of Materials Engineering, 2016, 44(5): 72-78.
http://dx.doi.org/10.11868/j.issn.1001-4381.2016.05.012

文章历史

收稿日期: 2014-09-28
修订日期: 2015-11-24
Ce68Al10Cu20Nb2大块非晶表面钝化膜的研究
王国材, 肖小波, 陈艳萍, 王晨    
福州大学 材料科学与工程学院, 福州 350116
摘要: 采用铜模冷铸法制备了Ce68Al10Cu20Nb2大块非晶合金,利用动电位极化曲线和电化学阻抗谱技术(EIS)研究了合金在1mol/L NaOH溶液中的腐蚀行为,并用扫描电子显微镜(SEM)对电化学钝化前后试样的表面形貌进行了表征,最后利用X射线光电子能谱(XPS)分析了电化学钝化处理获得的钝化膜的成分。结果表明:Ce68Al10Cu20Nb2 大块非晶合金在1mol/L NaOH溶液中具有明显的自钝化现象,钝化区为-0.25~0.50V,维钝电流密度为10-5~10-6A/cm2;通过电化学钝化后获得的钝化膜可分为外部疏松层和内部致密层;外层主要是Ce的氧化物/氢氧化物和 Nb的氧化物,内层则由Ce,Cu和Al的氧化物/氢氧化物和Nb的氧化物构成,钝化膜从外到内,随深度增加,氢氧化物含量逐渐减少,氧化物含量逐渐增加。
关键词: 非晶合金    腐蚀    极化    钝化膜    XPS   
Passive Film Formed on Ce68Al10Cu20Nb2 Bulk Amorphous Alloy
WANG Guo-cai, XIAO Xiao-bo, CHEN Yan-ping, WANG Chen    
College of Materials Science and Engineering, Fuzhou University, Fuzhou 350116, China
Abstract: The Ce68Al10Cu20Nb2 bulk amorphous alloy was prepared by injection casting into copper mold. The corrosion behaviors of the alloy in 1mol/L NaOH solution were investigated by potentiodynamic polarization curve method and electrochemical impedance spectroscopic (EIS) technique. The surface morphology of passive film was investigated by scanning electron microscopy (SEM). The composition of passive film was characterized using X-ray photoelectron spectroscopy (XPS). The results show that the Ce68Al10Cu20Nb2 bulk amorphous alloy exhibits a self-passivation phenomenon in 1mol/L NaOH solution with the passive region from -0.25V to 0.50V and the passive current density between 10-5-10-6A/cm2. The passive film obtained through electrochemical passivation consists of a porous outer layer and a dense inner layer. The outer layer is mainly composed of the oxides/hydroxides of Ce and the oxides of Nb,the inner layer is composed of the oxides/hydroxides of Ce, Cu,Al and the oxides of Nb. The content of hydroxides gradually decreases and the content of oxides gradually increases from the surface to the inside of the passive film.
Key words: amorphous alloy    corrosion    polarization    passive film    XPS   

近年来,大块非晶合金由于具有高强度、高弹性极限和高断裂韧性等特性,已成为材料学界的研究热点[1, 2, 3]。在各种块体非晶合金体系中,Ce基大块非晶合金具有优异的玻璃形成能力和极低的玻璃转变温度(低于100℃),在沸水中可以像塑料一样进行复杂的变形加工,具有极高的科学研究价值和广阔的应用前景[4, 5]。自Ce基非晶被开发以来,人们对其结构[6, 7, 8],物理力学性能[9, 10, 11],玻璃形成能力[12, 13]等方面展开了广泛的研究。如Pelletier等[14]发现,(Ce0.72Cu0.28)90-xAl10Fex大块非晶合金的玻璃化转变温度(Tg)和晶化温度(Tx)随Fe含量的增加而升高。Yu等[15]发现Ce基大块非晶合金的屈服强度随着外界温度的降低显著增大。Zhou等[13]发现适当降低Ce原料(用于制备Ce基非晶合金)的纯度可以提高Ce-Ga-Cu大块非晶合金的玻璃形成能力。

Ce基大块非晶合金的耐腐蚀性能,直接关系到它的实际应用和应用前景。目前,已有关于Ti基、Ni基等大块非晶合金耐腐蚀性方面的报道[16, 17],但是有关Ce基非晶合金耐腐蚀性方面的研究报道极少,日本的Inoue[18]小组已经做了抗氧化性方面的工作,发现Zn的添加可以提高Ce-Cu-Al非晶合金的抗氧化性,但这也只是一个开端。Zhang等[4]发现Ce-Al-Cu-Nb合金具有优异的玻璃形成能力,其中Ce68Al10Cu20Nb2棒状试样的最大直径可以达到8mm以上[4]。但到目前为止,鲜见Ce-Al-Cu-Nb大块非晶合金有关腐蚀方面的报道。本工作采用电化学工作站、扫描电子显微镜和X射线光电子能谱仪等,发现Ce-Al-Cu-Nb大块非晶合金在NaOH溶液中具有表面钝化现象,研究了大块非晶表面钝化膜的形成过程、微结构和元素分布。

1 实验

实验选用高纯度金属Ce(99.5%,质量分数,下同),Cu(99.995%),Al(99.999%)和Nb(99.999%)为原料,按照Ce68Al10Cu20Nb2(原子分数)的成分配比,利用真空电弧炉熔炼成合金铸锭,然后通过铜模冷铸法得到尺寸为1mm×8mm×30mm的板状非晶合金试样。测试前,将试样用 1200#,2000#,3000#SiC砂纸逐级打磨,然后抛光至表面光亮,分别用丙酮和酒精超声波清洗,冷风吹干后用于测试。

利用X射线衍射(XRD,D/max Ultima Ⅲ,CuKα)分析晶体结构。采用扫描电子显微镜(SEM,Zeiss Supra55)观察试样电化学钝化前后的微观形貌。采用X射线光电子能谱(XPS,ESCALAB-250)分析合金表面化学成分和元素化学状态,Ar+剥离束的能量为 3eV,电流密度为1μA/mm2,刻蚀速率为2.5nm/min。

电化学实验采用三电极体系,参比电极为氧化汞电极,本工作中电位都是相对于氧化汞电极,辅助电极为铂片,面积为2cm×2cm。实验采用CHI-660D的电化学工作站进行测试,实验前先测量开路电位,将试样放入1mol/L的NaOH 溶液中浸泡,待开路电位稳定后再进行极化曲线和交流阻抗谱(EIS)的测量。极化曲线的扫描速率为0.5mV/s,电势范围为-0.55~1.30V。交流阻抗谱测量时,交流正弦激励信号幅值为5mV,测试频率范围为1×10-2~1×105Hz,实验温度 25℃。根据极化曲线结果,将试样在-0.1V下恒电位钝化30min,得到用于分析的钝化膜。

2 结果与讨论

图 1为铜模快速凝固后制得的Ce68Al10Cu20Nb2合金的XRD图谱,可以看出,合金为单一的非晶态结构。Zhang等[4]在Ce基非晶合金的研究中也报道了类似的结果。

图1 铜模快速凝固后制得的Ce68Al10Cu20Nb2合金的XRD图谱 Fig.1 XRD pattern of Ce68Al10Cu20Nb2 bulk alloy solidified in copper mold

Ce68Al10Cu20Nb2大块非晶合金在1mol/L的NaOH溶液中的极化曲线如图 2所示。极化曲线上不存在活化-钝化区,这表明Ce68Al10Cu20Nb2非晶合金在NaOH溶液中会发生自钝化。极化曲线有较宽的钝化区,钝化区范围为-0.25~0.50V,维钝电流密度范围为10-5~10-6A/cm2。一般认为,金属材料的钝化区越宽,材料的耐点蚀能力越强,因此可知Ce-Al-Cu-Nb大块非晶合金在NaOH溶液中具有良好的耐点蚀能力。在阳极Tafel区没有呈现明显的直线段,如图 2中的局部放大图所示,这可能是由于该非晶合金在NaOH溶液中阳极溶解时,表面迅速形成了钝化膜,从而阻碍了合金的溶解过程[19]。将极化曲线的数据进行分析,可以得到Ce68Al10Cu20Nb2大块非晶合金在1mol/L NaOH溶液中的腐蚀电位为-0.405V,腐蚀电流密度为2.09×10-6A/cm2

图2 Ce68Al10Cu20Nb2大块非晶合金在1mol/L NaOH溶液中的极化曲线 Fig.2 Polarization curves of Ce68Al10Cu20Nb2 bulk amorphous alloy in 1mol/L NaOH solution

图 3(a)为Ce68Al10Cu20Nb2大块非晶合金电化学钝化前的SEM照片,在其表面只能观察到少量划痕。图 3(b)为电化学钝化后的SEM照片,在其表面可以观察到纳米颗粒状钝化膜。

图3 Ce68Al10Cu20Nb2大块非晶合金电化学钝化前后表面SEM照片 (a)钝化前;(b)钝化后 Fig.3 SEM images of Ce68Al10Cu20Nb2 bulk amorphous alloy surface (a)before electrochemical passivation;(b)after electrochemical passivation

Ce68Al10Cu20Nb2大块非晶合金在1mol/L NaOH溶液中,于-0.1V下恒电位钝化30min后的EIS谱如图 4所示。从图 4(a)可以看出,Bode图中存在高频和低频相角峰,说明存在两个时间常数,这表明合金表面形成了双层结构的钝化膜。从图 4(b)中可以看出,Nyquist图由两个容抗弧组成,分别位于高频区和低频区。其中,高频容抗弧反映的是外层膜的电阻和电容,低频容抗弧则与内层膜的电阻和电容相关。

图4 Ce68Al10Cu20Nb2大块非晶合金在-0.1V下恒电位钝化30min后的Bode图(a)和Niquist图(b) Fig.4 Bode(a) and Niquist(b) diagrams of Ce68Al10Cu20Nb2 bulk amorphous alloy passived at -0.1V for 30min

根据Nyquist图建立等效电路模型,如图 5所示。其中Rs为溶液电阻,QpRp分别表示外层膜的常相位角元件和电阻,表征外层膜与溶液界面的反应过程。 QbRb分别表示内层膜的常相位角元件和电阻,Rb越大,表明内层膜对于基体的防护作用越好。常相位角元件Q=1/Y0 ()nY0是常相位角元件Q的基本导纳,n为无量纲指数,表征Q偏离理想电容的程度[20]。EIS采用ZsimpWin软件进行参数解析,表 1为等效电路模型中的各参量经过拟合后得到的数值,等效电路图中的各参数拟合误差在4%以内,表明拟合结果和实验结果吻合良好。从图 4也可以看出,测量数据和拟合数据基本重合。

图5 Ce68Al10Cu20Nb2大块非晶合金在-0.1V下恒电位钝化30min后EIS的等效电路图 Fig.5 Equivalent circuits used to fit EIS of Ce68Al10Cu20Nb2 bulk amorphous alloy passived at -0.1V for 30min

表 1中拟合的数值可以看出,RbRp分别为43000Ω·cm2和168.8Ω·cm2Rb>>Rp,表明内层膜较为致密,外层膜较为疏松,且内层膜对非晶合金的耐腐蚀性能起决定作用。

表 1 Ce68Al10Cu20Nb2大块非晶合金在-0.1V下恒电位钝化30min后EIS的等效电路参数 Table 1 Equivalent circuit parameters for EIS of Ce68Al10Cu20Nb2 alloy passived at -0.1V for 30min
Rs/(Ω·cm2)Rp/(Ω·cm2)Qp-Y0/(Ω-1·cm-2·s-n)npRb/ (Ω·cm2)Qb-Y0/ (Ω-1·cm-2·s-n)nb
1.35168.84.51×10-40.74430004.6×10-40.66

利用 XPS对在1mol/L NaOH溶液中电化学钝化30min所形成的钝化膜的成分进行了分析。图 6为钝化膜对应刻蚀0,1,4min和10min的XPS图谱。可以看出,钝化膜外层中含有Ce元素、Nb元素和O元素,没有Al元素,Cu元素含量很少,说明Cu和Al这两种元素较之Ce和Nb,在形成钝化膜时会被优先腐蚀。从刻蚀1min以后的Cu2p (图 6(b))和Al2p(图 6(c))XPS图谱可以看出,随刻蚀时间延长,信号强度越来越大,表明越靠近外部,Cu和Al被腐蚀掉的越多。

图6 Ce68Al10Cu20Nb2大块非晶合金表面钝化膜对应不同刻蚀时间的XPS图谱 (a)Ce3d;(b)Cu2p;(c)Al2p;(d)Nb3d;(e)O1s Fig.6 XPS spectra with different sputtering time for passive film formed on the surface of Ce68Al10Cu20Nb2 bulk amorphous alloy (a)Ce3d;(b)Cu2p;(c)Al2p;(d)Nb3d;(e)O1s

图 7为钝化膜刻蚀10min后的XPS高分辨图谱(Ce3d,Cu2p,Al2p,Nb3d和O1s)的拟合结果。由图 7(a)Ce3d XPS图谱的分析可知,由于自旋-轨道相互作用,Ce3d的轨道分裂为两个能态,分别为Ce3d5/2 (v0vv′和v″)和Ce3d3/2(u0uu′和u″)。图谱是由4组Ce3d的自旋-轨道耦合双线组成,其中v0-u0(880.9,899.7eV)和v′-u′(886.0,904.6eV)是Ce3+的自旋-轨道耦合双线,v-u(882.5,901.1eV)和v″-u″(897.8,916.3eV)这两组是Ce4+的自旋-轨道耦合双线[21, 22, 23, 24]。对以上提到的4组峰分别积分后,可得到刻蚀10min后钝化膜中Ce3+和Ce4+的质量分数。通过计算表明,在刻蚀10min后,Ce3+ 占主导地位,约为65%。

图7 Ce68Al10Cu20Nb2大块非晶合金表面钝化膜的XPS高分辨谱图拟合结果(刻蚀10min后)(a)Ce3d;(b)Cu2p;(c)Al2p;(d)Nb3d;(e)O1s Fig.7 Fitting curves of high resolution XPS spectra for passive film formed on the surface of Ce68Al10Cu20Nb2 bulk amorphous alloy (after sputtering for 10min) (a)Ce3d;(b)Cu2p;(c)Al2p;(d)Nb3d;(e)O1s

由Cu2p的XPS图谱(图 7(b))可以看出,由于自旋-轨道相互作用,Cu2p的轨道分裂为两个能态,分别为Cu2p3/2和Cu2p1/2。在刻蚀10min后,Cu2p3/2包含了3个峰,其中932.7eV处的峰对应Cu+(Cu2O)和Cu0[25],933.6eV和935.1eV处的峰分别对应CuO[25]和Cu(OH)[25, 26]2中的Cu2+。939.0~945.0eV之间的峰为Cu2+的卫星伴峰[27]。Cu2p1/2包含952.4eV和953.4eV两个峰,分别对应Cu+(Cu2O)和Cu2+(CuO)[25]。以图 7(b)的分析为基础,结合图 6(b)可以看出,随着刻蚀时间的延长,CuO和Cu(OH)2的含量逐渐减少,Cu2O逐渐增加,在刻蚀10min时,Cu+比例达到66%。这是因为Cu2O在空气中不稳定,很容易氧化变成CuO,所以最外层没有Cu2O[28]

由Al2p的XPS图谱(图 7(c))可以看出,在刻蚀10min后,Al2p分为3个峰,72.4eV是Al0[29]对应的峰,位于 75.2eV附近的峰为Al3+,对应的存在形式为Al2O[29]3,77.8eV对应的是 Cu3p,Qin等在研究Zr-Al-Cu-Ni-Pd大块非晶合金时也有此发现[30]。结合图 6(c)可以看到,在刻蚀1min后,位于 74.3eV的峰对应的是Al(OH)3中的Al3+[31]。此外,该图谱中还发现存在少量的Al2O3。以上表明,在1mol/L NaOH溶液中钝化30min后得到的钝化膜中,表层不含Al元素,内层随深度增加,Al(OH)3逐渐减少,Al2O3逐渐增加,在刻蚀到10min时,只存在 Al2O3,并出现少量Al单质。

通过对刻蚀10min后Nb3d的XPS图谱(图 7(d))进行分析,并结合不同刻蚀时间的Nb3d XPS图谱(图 6(d))可以看到,随刻蚀时间的延长,图谱并无明显变化。Nb的氧化物为NbO(203.8eV和206.8eV),NbO2(205.8eV和208.5eV)和Nb2O5(207.0eV和210.3eV)[32, 33],其中Nb2O5含量最多,NbO含量最少,在刻蚀10min时,Nb5+约为60%。

在刻蚀10min后O1s 的XPS图谱(图 7(e))中,529.8eV对应CeO2中的氧峰[34],530.9eV代表M—O键(M代表Ce,Cu,Al和Nb元素)。532.0eV对应的是Ce—OH 键[34]和Cu—OH键,此时的—OH 键含量已经很少。与之对应的钝化膜未经刻蚀时O1s的XPS图谱如图 8所示,529.8eV对应CeO2中的氧峰,530.8eV处的峰,对应的是Ce2O3,CuO及Nb的氧化物中的氧峰[32, 34],532.0eV对应的是Ce—OH键,含量最多。结合O的XPS图谱(图 6(e)图 7(e)图 8)分析可知,随刻蚀时间的延长,氢氧化物逐渐减少,氧化物逐渐增多。

图8 Ce68Al10Cu20Nb2大块非晶合金表面钝化膜O1s高分辨XPS谱图的拟合结果(未刻蚀) Fig.8 Fitting curves of O1s high resolution XPS spectrum for passive film formed on the surface of Ce68Al10Cu20Nb2 bulk amorphous alloy(before sputtering)

综上所述,结合所有XPS图谱分析可知,通过电化学钝化得到的钝化膜,外层元素分布和内层分布差别较大,外层不含Al,含有少量的Cu,在刻蚀1min后,即出现明显的Cu峰和Al峰,可知外层很薄。膜的外层由于氧含量最高,有可能形成金属氢氧化合物,如Ce(OH)3,Ce(OH)4等,从外到内,随深度增加,氢氧化物含量逐渐减少,此时膜内层主要形成金属氧化物。在内层膜中,Ce3+和Cu+的含量要比Ce4+和Cu2+多,Al和Nb则主要以Al2O3和Nb2O5居多。

3 结论

(1)Ce68Al10Cu20Nb2大块非晶合金在NaOH溶液中表现出明显的自钝化行为,钝化区范围为-0.25~0.50V,维钝电流密度范围为10-5~10-6A/cm2

(2)Ce68Al10Cu20Nb2大块非晶合金在NaOH溶液中通过电化学钝化形成内层致密、外层疏松的双层结构的钝化膜,致密内层对材料的耐腐蚀性能起决定性作用。

(3)钝化膜外层主要由Ce的氧化物和氢氧化物以及Nb的氧化物构成,此外还有少量Cu的氧化物。内层则由Ce,Cu,Al和Nb的氧化物及氢氧化物构成,由外到内,随深度增加,氢氧化物逐渐减少,氧化物最终占据绝大部分。

参考文献(References)
[1] 汪卫华. 金属玻璃研究简史[J]. 物理,2011, 40 (11) : 701 –709. WANG Wei-hua. A brief history of metallic glasses[J]. Physics,2011, 40 (11) : 701 –709.
[2] 胡壮麒, 张海峰. 块状非晶合金及其复合材料研究进展[J]. 金属学报,2010, 46 (11) : 1391 –1421. HU Zhuang-qi, ZHANG Hai-feng. Recent progress in the area of bulk amorphous alloy and composites[J]. Acta Metallurgica Sinica,2010, 46 (11) : 1391 –1421.
[3] PARK E S, KIM D H. Design of bulk metallic glasses with high glass forming ability and enhancement of plasticity in metallic glass matrix composites: a review[J]. Metals and Materials International,2005, 11 (1) : 19 –27.
[4] ZHANG B, ZHAO D Q, PAN M X, et al. Amorphous metallic plastic[J]. Physical Review Letters,2005, 94 (20) : 1 –4.
[5] ZHANG B, WANG R J, ZHAO D Q, et al. Properties of Ce-based bulk metallic glass-forming alloys[J]. Physical Review B,2004, 70 (22) : 1 –7.
[6] ZHANG T, LI R, PANG S. Effect of similar elements on improving glass-forming ability of La-Ce-based alloys[J]. Journal of Alloys and Compounds,2009, 483 (1-2) : 60 –63.
[7] LI R, PANG S J, MEN H, et al. Formation and mechanical properties of (Ce-La-Pr-Nd)-Co-Al bulk glassy alloys with superior glass-forming ability[J]. Scripta Materialia,2006, 54 (6) : 1123 –1126.
[8] BAI Y Y, GENG Y L, JIANG C M, et al. β relaxation and its composition dependence in Ce-based bulk metallic glasses[J]. Journal of Non-Crystalline Solids,2014, 390 : 1 –4.
[9] FORNELL J, SURIÑACH S, BARÓ M D, et al. Unconventional elastic properties, deformation behavior and fracture characteristics of newly developed rare earth bulk metallic glasses[J]. Intermetallics,2009, 17 (12) : 1090 –1097.
[10] WEI B C, ZHANG T H, ZHANG L C, et al. Plastic deformation in Ce-based bulk metallic glasses during depth-sensing indentation[J]. Materials Science and Engineering: A,2007, 449-451 : 962 –965.
[11] ZHANG L C, WEI B C, XING D M, et al. The characterization of plastic deformation in Ce-based bulk metallic glasses[J]. Intermetallics,2007, 15 (5-6) : 791 –795.
[12] XU B C, XUE R J, ZHANG B. Superior glass-forming ability and its correlation with density in Ce-Ga-Cu ternary bulk metallic glasses[J]. Intermetallics,2013, 32 : 1 –5.
[13] ZHOU Y, ZHAO Y, QU B Y, et al. Remarkable effect of Ce base element purity upon glass forming ability in Ce-Ga-Cu bulk metallic glasses[J]. Intermetallics,2014, 56 : 56 –62.
[14] QIAO J C, PELLETIER J M. Thermal stability of (Ce0.72Cu0.28)90-xAl10Fex(x=0, 5 or 10) bulk metallic glasses[J]. Physica Status Solidi (c),2011, 8 (11-12) : 3074 –3077.
[15] YU P, CHAN K C, CHEN W, et al. Low-temperature mechanical properties of Ce[J]. Philosophical Magazine Letters,2011, 91 (1) : 70 –77.
[16] 胡侨, 张敏, 李海飞, 等. Ti-Zr-Cu-Co-Sn-Si块体非晶合金的形成及生物腐蚀行为和力学性能[J]. 材料工程,2014 (6) : 18 –21. HU Qiao, ZHANG Min, LI Hai-fei, et al. Formation, bio-corrosion behavior and mechanical properties of Ti-Zr-Cu-Co-Sn-Si bulk metallic glasses[J]. Journal of Materials Engineering,2014 (6) : 18 –21.
[17] 邱春龙, 黄璐, 卢旭阳, 等. Ni-Ti(-Zr)-P非晶合金的热稳定性及腐蚀行为[J]. 稀有金属材料与工程,2013, 42 (5) : 975 –978. QIU Chun-long, HUANG Lu, LU Xu-yang, et al. Thermal stability and corrosion behavior of Ni-Ti(-Zr)-P glassy alloys[J]. Rare Metal Materials and Engineering,2013, 42 (5) : 975 –978.
[18] BIAN Z, INOUE A. New Ce-Cu-Al-Zn bulk metallic glasses with high oxidation resistance[J]. Materials Transactions,2006, 47 (10) : 2599 –2602.
[19] GEBERT A, MUMMERT K, ECKERT J, et al. Electrochemical investigations on the bulk glass forming Zr55Cu30Al10Ni5 alloy[J]. Materials and Corrosion,1997, 48 (5) : 293 –297.
[20] WU H, WANG Y, ZHONG Q, et al. The semi-conductor property and corrosion resistance of passive film on electroplated Ni and Cu-Ni alloys[J]. Journal of Electroanalytical Chemistry,2011, 663 (2) : 59 –66.
[21] 纪红, 许越, 周德瑞, 等. LY12铝合金表面铈纳米膜的制备及显微组织特征[J]. 航空材料学报,2003, 23 (1) : 21 –23. JI Hong, XU Yue, ZHOU De-rui, et al. Process and microstructure characters of ceria nanocrystalline film on aluminium alloy LY12[J]. Journal of Aeronautical Materials,2003, 23 (1) : 21 –23.
[22] MONTEMOR M F, SIMÕES A M, FERREIRA M G S, et al. Composition and corrosion resistance of cerium conversion films on the AZ31 magnesium alloy and its relation to the salt anion[J]. Applied Surface Science,2008, 254 (6) : 1806 –1814.
[23] 康俊龙, 姚兰芳, 杨松林, 等. Ce掺杂TiO2纳米复合薄膜的制备及光催化活性[J]. 人工晶体学报,2013, 42 (4) : 671 –676. KANG Jun-long, YAO Lan-fang, YANG Song-lin, et al. Preparation and photocatalytic activity of Ce-doped TiO2 composite nanometer films[J]. Journal of Synthetic Crystals,2013, 42 (4) : 671 –676.
[24] LARACHI F, PIERRE J, ADNOT A, et al. Ce 3d XPS study of composite CexMn1-xO2-y wet oxidation catalysts[J]. Applied Surface Science,2002, 195 (1-4) : 236 –250.
[25] TAN C W, DAUD A R, YARMO M A. Corrosion study at Cu-Al interface in microelectronics packaging[J]. Applied Surface Science,2002, 191 (1-4) : 67 –73.
[26] PROCACCINI R, SCHREINER W H, VAZQUEZ M, et al. Surface study of films formed on copper and brass at open circuit potential[J]. Applied Surface Science,2013, 268 : 171 –178.
[27] MARQUES M T, FERRARIA A M, CORREIA J B, et al. XRD, XPS and SEM characterisation of Cu-NbC nanocomposite produced by mechanical alloying[J]. Materials Chemistry and Physics,2008, 109 (1) : 174 –180.
[28] KUNZE J, MAURICE V, KLEIN L H, et al. In situ STM study of the duplex passive films formed on Cu(111) and Cu(001) in 0.1 M NaOH[J]. Corrosion Science,2004, 46 (1) : 245 –264.
[29] BRAJPURIYA R, SHRIPATHI T. Investigation of Fe/Al interface as a function of annealing temperature using XPS[J]. Applied Surface Science,2009, 255 (12) : 6149 –6154.
[30] QIN F X, ZHANG H F, CHEN P, et al. Corrosion behavior of bulk amorphous Zr55Al10Cu30Ni5-xPdx alloys[J]. Materials Letters,2004, 58 (7-8) : 1246 –1250.
[31] WANG X M, ZHU L Q, HE X, et al. Effect of cerium additive on aluminum-based chemical conversion coating on AZ91D magnesium alloy[J]. Applied Surface Science,2013, 280 : 467 –473.
[32] MILOŠEV I, KOSEC T, STREHBLOW H H. XPS and EIS study of the passive film formed on orthopaedic Ti-6Al-7Nb alloy in Hank's physiological solution[J]. Electrochimica Acta,2008, 53 (9) : 3547 –3558.
[33] HALBRITTER J. On the oxidation and on the superconductivity of niobium[J]. Applied Physics A,1987, 43 (1) : 1 –28.
[34] YU X, LI G. XPS study of cerium conversion coating on the anodized 2024 aluminum alloy[J]. Journal of Alloys and Compounds,2004, 364 (1-2) : 193 –198.