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负偏压和本底真空度对Al膜表面形貌和耐蚀性能的影响

  • 胡方勤1

    机 构：

    1. 中国科学院 宁波材料技术与工程研究所 中国科学院海洋新材料与应用技术重点实验室 浙江省海洋材料与防护技 术重点实验室, 宁波 315201

    ×
  • ， 曹振亚2

    机 构：

    2. 中国科学技术大学 纳米科学技术学院, 合肥 230026

    ×
  • ， 张青科1

    机 构：

    1. 中国科学院 宁波材料技术与工程研究所 中国科学院海洋新材料与应用技术重点实验室 浙江省海洋材料与防护技 术重点实验室, 宁波 315201

    ×
  • ， 杨丽景1

    机 构：

    1. 中国科学院 宁波材料技术与工程研究所 中国科学院海洋新材料与应用技术重点实验室 浙江省海洋材料与防护技 术重点实验室, 宁波 315201

    ×
  • ， 宋振纶1

    机 构：

    1. 中国科学院 宁波材料技术与工程研究所 中国科学院海洋新材料与应用技术重点实验室 浙江省海洋材料与防护技 术重点实验室, 宁波 315201

    ×

1. 中国科学院 宁波材料技术与工程研究所 中国科学院海洋新材料与应用技术重点实验室 浙江省海洋材料与防护技 术重点实验室, 宁波 315201；
2. 中国科学技术大学 纳米科学技术学院, 合肥 230026；

Effects of Negative Bias Voltage and Base Vacuum Degree on Surface Morphology and Corrosion Resistance of Al Coatings

  • HU Fangqin1

    Affiliation：

    1. Zhejiang Key Laboratory of Marine Materials and Protective Technologies, Key Laboratory of Marine Materials and Related Technologies, Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo 315201 , China

    ×
  • ， CAO Zhenya2

    Affiliation：

    2. Nano Science and Technology Institute, University of Science and Technology of China, Hefei 230026 , China

    ×
  • ， ZHANG Qingke1

    Affiliation：

    1. Zhejiang Key Laboratory of Marine Materials and Protective Technologies, Key Laboratory of Marine Materials and Related Technologies, Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo 315201 , China

    ×
  • ， YANG Lijing1

    Affiliation：

    1. Zhejiang Key Laboratory of Marine Materials and Protective Technologies, Key Laboratory of Marine Materials and Related Technologies, Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo 315201 , China

    ×
  • ， SONG Zhenlun1

    Affiliation：

    1. Zhejiang Key Laboratory of Marine Materials and Protective Technologies, Key Laboratory of Marine Materials and Related Technologies, Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo 315201 , China

    ×

1. Zhejiang Key Laboratory of Marine Materials and Protective Technologies, Key Laboratory of Marine Materials and Related Technologies, Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo 315201 , China；
2. Nano Science and Technology Institute, University of Science and Technology of China, Hefei 230026 , China；

通讯作者:

宋振纶(1967—),男(汉),研究员,博士;研究方向:磁性材料表面防护;E-mail:songzhenlun@nimte.ac.cn

中图分类号:TG178

文献标识码:A

文章编号:1007-9289(2020)04-0128-08

DOI:10.11933/j.issn.1007-9289.20200721001

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目录contents

    摘要

    采用电弧离子镀技术在烧结钕铁硼表面沉积 Al 薄膜。 利用表面轮廓仪、扫描电镜、激光共聚焦、电化学工作站和盐雾试验箱分析了负偏压和本底真空度对镀层形貌、性能和沉积速率的影响。 结果表明,镀层表面的液滴数量和粒径随负偏压和本底真空度的增加而减小;沉积速率与负偏压成反比,而与本底真空度成正比。 在负偏压为-100 V 时沉积速率最大,达到 4. 85 μm/ h。 随着负偏压和本底真空度的增加,腐蚀电流密度减小,耐盐雾时长增加,负偏压为 -200 V 时 Al / NdFeB 样品具有较好的耐蚀性。

    Abstract

    Al coatings were deposited on sintered NdFeB through arc ion plating technique. The effects of negative bias voltage and base vacuum degree on morphology, performance and deposition rate of the coatings were investigated by surface profilometer, SEM, LSCM, electrochemical workstation and salt spray chamber. Results show that the number and size of droplets on coatings decrease with the increase of negative bias voltage and base vacuum degree. The deposition rate is inversely proportional to the negative bias voltage and directly proportional to the base vacuum degree, and the maximum deposition rate is 4. 85 μm/ h at negative bias voltage of -100 V. The corrosion current density decreases and the resistance time to salt spray increases with the increase of negative bias voltage and the base vacuum degree, and the Al/ NdFeB sample has a high corrosion resistance at negative bias voltage of -200 V.

  • 0 引言

  • 烧结钕铁硼永磁体具有高磁能积、高矫顽力和高能量密度等优异性能[1-2],被广泛应用于新能源车、家电、计算机、风电及航天等领域。但钕铁硼磁体由于本身成分的原因,在使用环境下耐蚀性较差,阻碍了其进一步应用[3-7]。表面防护处理是提高烧结钕铁硼耐蚀性的有效手段,其中物理气相沉积(蒸发、磁控溅射和电弧离子镀等) 是一种环境友好型技术[8],已在磁体表面防护方面取得了一些进展。由于铝是一种低成本材料, 且具备高耐腐蚀性[9-10],故常作为气相沉积的靶材。然而,利用磁控溅射在NdFeB表面沉积的铝膜呈柱状结构,腐蚀液易渗透到基体,导致涂层过早失效[11]。 MAO S D等[12]将IBAD-Al涂层沉积在烧结NdFeB上,抑制了柱状晶的生长,但由于沉积速率较低,未在工业领域得到广泛应用。

  • 与其他物理气相沉积技术相比,电弧离子镀具有致密度高、附着力好、沉积速率快、绕射性好等优点,越来越受到人们的关注[13-15]。近年来, 电弧离子镀在NdFeB表面防护方面也取得了一些研究成果[16-17],国内外学者研究了靶电流、基体温度、靶基距、基体转速等参数对镀层微观结构和性能的影响[18-20]。但在NdFeB表面沉积低熔点Al膜的研究相对较少,其制备工艺、防护机理等需要进一步研究。基于此,文中利用电弧离子镀在NdFeB表面沉积一层Al膜,研究了负偏压和本底真空度对镀层沉积速率、形貌及耐蚀性的影响。

  • 1 试验

  • 1.1 薄膜制备

  • 选用尺寸规格为20 mm × 10 mm × 3 mm的商用N35 烧结NdFeB材料为试样,经超声除油、清洗、吹干后,放入体积比为5%的HNO3 中浸泡2 min,然后依次在丙酮和酒精中超声清洗10 min。

  • 将样品表面正对真空腔体的高纯Al靶(纯度99.99%、直径 Φ100 mm、厚度40 mm),靶基距为35 cm。抽真空后,以60 cm 3/min的流速通入高纯氩气(纯度99.999%),沉积前,利用离子源对NdFeB表面清洗20 min。工作时,靶电流为60 A,工作压力为1.0 Pa,并在基体上施加偏压, 沉积不同的时间,铝膜厚度均接近5 μm。为进行对比,在不同偏压(A组)和不同真空度(B组) 下制备一系列薄膜。 A组试验条件为:本底真空度固定为4.0 × 10-4 Pa, 基体负偏压分别为-100、-150 和-200 V;B组试验条件为:基体负偏压固定为-100 V,本底真空度分别为4.0 × 10-4 、7.0×10-4 、1.0×10-3 和1.3×10-3 Pa,具体工艺参数如表1 所示。

  • 1.2 结构与耐蚀性能表征

  • 采用表面轮廓仪(Alpha-Step, IQ)测量薄膜的厚度。采用扫描电镜( SEM, FEI QuantaFEG250)观察表面及截面形貌。使用image-pro plus软件自动计数液滴的大小和数量。采用激光共聚焦显微镜( LSCM, 700) 测量薄膜的表面粗糙度。

  • 表1 电弧离子镀Al薄膜的沉积参数

  • Table1 Deposition parameters of Al coatings prepared via arc ion plating

  • 利用电化学工作站和中性盐雾试验箱测试了薄膜的腐蚀行为。电化学工作站( PGSTAT302, Autolab) 测量开路电位,电化学试验前,先将AIP-Al试样在质量分数为3.5%NaCl溶液中浸泡60 min,测试温度为(25±3)℃。采用三电极进行电化学试验,其中饱和甘汞作为参比电极,1 cm×1 cm的铂片作为对电极,试样作为工作电极。中性盐雾试验按照国家标准(GB/T10125-2012)在盐雾试验箱中进行,NaCl溶液浓度为50 g/dm 3,温度为(35±2) °C,盐雾的试样为镀膜后再进行3 价铬钝化处理的样品。

  • 2 结果与讨论

  • 2.1 Al薄膜的沉积速率

  • 本底真空度为4.0×10-4 Pa时,基体偏压与沉积速率的关系如图1 所示。随着基体负偏压的增加,沉积速率减小,负偏压为-100 V时沉积速率最大,达到4.85 μm/h。基体负偏压可以促进粒子电离并加速,赋予Al离子轰击基体的能量,在基体上沉积的同时还具有反溅射作用。在负偏压为-100 V时,沉积作用占主导地位,因此其沉积速率较大。而继续增大负偏压,轰击能量也随之加大,反溅射作用明显,沉积速度降低。另外负偏压的增加导致基体附近的电荷排斥力增加,沉积速率也会下降[21]。

  • 负偏压为-100 V时,真空度与沉积速率的关系如图2 所示。本底真空度越高,沉积速率越大,由1.3×10-3 Pa下的4.34 μm/h增加至4.0×10-4 Pa下的4.85 μm/h。在本底真空度为1.3× 10-3 Pa的低真空条件下,真空腔体内残余杂质气体较多,这些杂质气体分子与高能Ar +频繁碰撞, 使得Ar +轰击靶材表面的能量降低而散射几率增加,从而导致靶材离子的离化效率降低,单位时间内沉积到基体表面的离子数目下降[22]。

  • 图1 不同负偏压下Al膜沉积速率

  • Fig.1 Deposition rates of Al coatings at different negative bias voltages

  • 从图1 和图2 可以看出,随着偏压的增加, 反溅射作用加大,沉积速率下降较快;而当腔体到达一定的真空度后,腔体内部杂质气体较少,随着真空度的降低,沉积速率下降相对平缓。与真空度相比较,负偏压对沉积速率影响较大。

  • 图2 不同本底真空度下的Al膜沉积速率

  • Fig.2 Deposition rates of Al coatings at different base vacuum degrees

  • 2.2 薄膜形貌

  • 图3 显示了不同负偏压下Al膜的表面形貌(图3(a)~图3(c))和截面形貌(图3(d)~图3(f)),从表面形貌可以看出,Al膜表面致密、均匀,同时伴有大量颗粒物,这些颗粒物来源于Al靶材电弧蒸发过程中产生的熔滴或未电离的中性原子。随着基体负偏压的升高,表面液滴的数量和大小均下降。为了更直观地反映表面液滴分布情况,利用image-pro plus软件自动统计了液滴的大小和数量,结果如图4 所示。

  • 图3 不同负偏压下Al膜的形貌

  • Fig.3 Morphologies of Al coatings at different negative bias voltages

  • 图4 不同负偏压下Al膜表面液滴密度和数量

  • Fig.4 Density and quantities of droplets on Al coatings at different negative bias voltages

  • 图4 中可以看出,液滴的尺寸主要分布在小尺寸范围内(0~3、3~6 和6~9 μm),3~6 μm的液滴数量最多。随着偏压的增加,大液滴数量明显减少,当负偏压增加到-200 V时, 9 μm以上的液滴显著减少,而小颗粒数(0~3 μm)明显增加。这是因为在基体附近存在一个等离子体鞘层,带负电荷的大颗粒进入鞘层时,受到鞘层内电场排斥力作用[23],负偏压越大,排斥力越大, 导致部分液滴无法到达基体表面,相应的数量也会减少。

  • 从截面形貌来看,薄膜表面有很多液滴,液滴的存在导致沉积的铝膜表面不光滑。从图3 可以发现,随着偏压从-100 V增加到-200 V, 截面上出现了小凹坑(从激光共聚焦图图5 也可以看出)。这是因为随着偏压的增加,溅射出的Al离子在加速电场的作用下获得了更高的能量,与基体上的薄膜发生碰撞,形成小凹坑。多弧离子镀沉积的Al膜截面上未出现柱状晶结构,且薄膜和基体之间没有缝隙,结构较为致密。这可能是因为多弧离子镀溅射出来的Al离子能量较高,沉积在基体上时,Al离子扩散的更均匀,有助于消除柱状晶结构,形成更致密薄膜结构。

  • 图5 不同负偏压下Al膜表面粗糙度

  • Fig.5 Surface roughness of Al coatings at different negative bias voltages

  • 不同偏压下薄膜的表面粗糙度(Ra)如图5 所示。图5(a)、图5(b)和图5(c)的Ra测试值分别为1.120、1.230 和1.164 μm。随着负偏压值增大,Ra 的数值先略增大而后降低,数值差别不大,这可能是因为在高的负偏压下,溅射出的离子在外加电场作用下加速沉积到基体薄膜,轰击作用导致涂层表面较为粗糙。

  • 不同本底真空度下镀Al膜形貌如图6 所示。图中可以观察到表面有大量瘤状及花状液滴,液滴数量随着真空度的降低而增加。图7 是Al液滴数量和尺寸分布的统计图。由图可知,液滴的粒径分布主要集中在3~6 μm范围内。当真空度从1.3×10-3 Pa增加到4.0×10-4 Pa时,液滴数量逐渐减少。在真空度为1.3×10-3 Pa时, 6~15 μm的大液滴数量较多,而在4.0×10-4 Pa条件下,0~6 μm的液滴略有增加,6 μm以上的大颗粒明显减少。这些变化可能归因于真空度越高,腔体内残余氧等有害气体越少,带电粒子与气体分子碰撞次数减少,镀层表面形貌污染较小[24]。

  • 从截面形貌分析,Al膜表层有许多高低起伏类似山丘的包状结构, 这些包状结构即为大液滴。

  • 随着真空度的降低,腔体中的杂质增多,杂质吸附在基体上,在成核的过程中容易形成粗大的晶粒。膜基界面处未发现微裂纹,结构致密。

  • 不同本底真空度下镀Al膜的表面粗糙度(Ra)如图8 所示,由图可知,真空度为4.0×10 -4 Pa的薄膜表面较为光滑,液滴尺寸较小,而1.3× 10 -3 Pa真空度下的表面可以观察到明显的起伏状的丘陵形貌,7.0×10-4 和1.0×10-3 Pa真空度下也可观察到微小的起伏形貌, 但不明显。图8(a)~图8( d) 的表面粗糙度测量值分别为1.12、1.168、1.171 和1.367 μm,即随着真空度降低,Al/NdFeB体系的 Ra 值增大,这是因为真空度降低,腔体内的杂质增多,杂质吸附在基体表面,使基体表面的Al膜出现不均匀的沉积,表面结构较为粗糙。

  • 图6 不同本底真空度下的Al膜表面及截面形貌

  • Fig.6 Surface and cross-section morphologies of Al coatings at different base vacuum degrees

  • 图7 不同真空度下Al膜表面液滴密度和数量

  • Fig.7 Density and quantities of droplets on Al coatings at different base vacuum degrees

  • 2.3 动电位极化曲线

  • 图9 为不同偏压下的Al/NdFeB样品以及未镀膜的NdFeB样品在3.5%NaCl溶液中测得的极化曲线。从图中可以看出,Al膜在阳极区有明显的钝化区,阳极区钝化行为可能与Al膜表面产生的一层氧化物薄膜有关。一般认为,腐蚀电流(Icorr)越小,腐蚀电位(Ecorr)越高,耐腐蚀性能就越好。不同偏压下镀膜/未镀膜样品 Ecorr 和 Icorr 如表2 所示,与未镀膜NdFeB样品相比,腐蚀电位变化不明显,仅有在负偏压为-200 V时获得的Al/NdFeB样品腐蚀电位正方向略有提高, 但3 种负偏压下获得的Al/NdFeB的腐蚀电流密度都比基体NdFeB(3.740 μA/cm 2 )降低了2 个数量级。随着负偏压的增加,腐蚀电流密度从0.054 μA/cm 2 (-100 V) 下降到0.012 μA/cm 2 (-200 V),降低了4.5 倍,说明薄膜对NdFeB样品起到了很好的防护作用,且负偏压为-200 V时Al/NdFeB样品的防护效果较好。薄膜防腐蚀性能的提高与其结构有密切关联。在高偏压下, 由于基体附近排斥力和薄膜表面的轰击作用,Al膜表面液滴数量、松散颗粒减少,同时粒径减小, 从而减少了表面缺陷,提高了薄膜的结合力和致密度,因而薄膜的耐蚀性能得到改善。

  • 图8 不同本底真空度下Al膜表面粗糙度

  • Fig.8 Surface roughness of Al coatings at different base vacuum degrees

  • 图9 不同负偏压下的Al膜动态极化曲线

  • Fig.9 Potentiodynamic polarization curves of Al coatings at different negative bias voltages

  • 表2 不同负偏压下镀膜/未镀膜样品腐蚀电压及腐蚀电流密度数值表

  • Table2 Value of corrosion potential and corrosion current density of deposited specimens and bare NdFeB at different negative bias voltages

  • 图10 为不同真空度下Al/NdFeB样品和未镀膜NdFeB样品在质量分数为3.5%NaCl溶液中测得的极化曲线。 Ecorr 和 Icorr 如表3 所示,由表可知,随着真空度的增加,腐蚀电流密度明显减小, 腐蚀电流密度从0.401 μA/cm 2(1.3×10-3 Pa)下降到0.054 μA/cm 2 ( 4.0 × 10-4 Pa), 降低接近90%。与未镀膜的NdFeB样品相比,4 种真空度下的Al/NdFeB样品腐蚀电流都比基体钕铁硼(3.740 μA/cm 2 )降低了1~2 个数量级,说明薄膜对NdFeB样品起到了防护作用,且真空度越高,防护效果越好。可能是因为真空度越高,腔体内有害气体越少,沉积到基体上薄膜表面的缺陷越少,提高了结合力和表面质量。

  • 图10 不同本底真空度下的Al膜动态极化曲线

  • Fig.10 Potentiodynamic polarization curves of Al coatings at different base vacuum degrees

  • 表3 不同本底真空度下镀膜/未镀膜样品腐蚀电压及腐蚀电流密度数值表

  • Table3 Corrosion potential and corrosion current density of deposited specimens and bare NdFeB at different base vacuum degrees

  • 2.4 耐蚀性

  • 不同负偏压下获得的镀膜样品经过240 h中性盐雾试验后的表面形貌如图11 所示。可见-100 V时Al/NdFeB样品出现轻微红色锈蚀,-150 V时Al/NdFeB样品表面出现较严重的红色锈蚀,-200 V时Al/NdFeB样品表面腐蚀不明显,与极化曲线结果基本一致。-150 V负偏压条件下的薄膜盐雾腐蚀较为严重,这可能是因为负偏压为-150 V时表面有大液滴与凹坑,表面较粗糙(图5),腐蚀介质沿缺陷处进入,从而加速基体材料的腐蚀,而负偏压为-200 V时,Al膜表面缺陷较少,均匀性、致密性较好,从而有效阻挡了腐蚀液渗入,提高了耐蚀性。

  • 图11 不同负偏压下Al膜240 h盐雾试验图

  • Fig.11 Images of Al coatings deposited at different negative bias voltages for 240 h

  • 图12 为在4.0×10-4和7.0×10-4 Pa两种真空度下镀Al膜的样品分别经过120 和240 h盐雾试验后的形貌。盐雾试验72 h后,1.3 × 10-3 和1.0×10-3 Pa条件下镀膜的Al/NdFeB开始出现腐蚀点,而4.0×10-4 和7.0×10-4 Pa条件下制备的薄膜则未出现腐蚀点;试验进行到120 h, 4.0×10-4 和7.0×10-4 Pa条件下制备的Al薄膜均出现了灰色的腐蚀点;继续进行到240 h,4.0× 10-4 Pa下制备的Al膜表面仍未发生较大变化, 而7.0×10-4 Pa下制备的薄膜样品腐蚀点明显增多,且可以看到裸露的基体。盐雾试验的结果表明,基底真空度越高,Al膜耐蚀性越强,与极化曲线结果相一致。

  • 图12 不同本底真空度下沉积的Al膜盐雾试验结果

  • Fig.12 Results of Al coatings deposited at different base vacuum degrees after NSS test

  • 从盐雾试验结果分析,耐腐蚀性能与薄膜的结构紧密相关。在基体上施加不同负偏压,基体的表面形成等离子壳层,等离子体壳层的存在有助于抑制大液滴沉积在薄膜上,随着负偏压从-100 V增加到-200 V,沉积在薄膜上的液滴数目减少,尺寸减小,形成相对致密的薄膜,从而提高了薄膜对基体的保护能力。随着本底真空度的提高,液滴的数目有所降低,薄膜的结构就会越致密,因此镀膜后的基体更耐腐蚀。

  • 研究显示,使用真空直流磁控溅射技术在烧结NdFeB基体上镀的纯Al膜呈柱状晶结构,并且Al膜与基体间存在缝隙[8]。当Al/NdFeB处在电化学环境中时,Cl离子通过柱状晶的晶界穿透基体,导致基体失效。相比磁控溅射技术,电弧离子镀技术的靶材离化率高,沉积温度高,有利于Al离子在基体表面扩散,可消除薄膜的柱状晶结构,更有效地保护基体不受腐蚀。

  • 3 结论

  • (1) 负偏压越小,本底真空度越高,沉积速率越大。在负偏压为-100 V、本底真空度为4.0×10-4 Pa时,沉积速率最大,达到4.85 μm/h。

  • (2) 随着负偏压和本底真空度的增加,Al/NdFeB样品表面液滴数量减少,粒径尺寸减小, Al膜表面质量和致密性提高。

  • (3) Al/NdFeB样品的自腐蚀电流密度随着负偏压和本底真空度的增加而明显降低,较未镀膜NdFeB样品降低了1~2 个数量级。中性盐雾试验表明,负偏压为-200 V时Al/NdFeB样品的防护性能最好,与动态极化曲线结果相一致。

  • 参考文献

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    • [3] JACOBSON J,KIM A.Oxidation behavior of Nd-Fe-B mag-nets [J].Journal of Applied Physics,1987,(61):3763-3765.

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    • [5] GURAPPA I.Corrosion characteristics of permanent magnets in acidic environments [J].Journal of Alloys and Com-pounds,2003,360(1-2):236-242.

    • [6] EDGLEY D S,BRETON J M L,STEYAERT S,et al.Char-acterisation of high temperature oxidation of NdFeB magnets [J].Journal of Magnetism and Magnetic Materials,1997,173(1/2):29-42.

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  • 基本信息

    中图分类号: TG178
    文献标识码: A
    DOI: 10.11933/j.issn.1007-9289.20200721001
    文章编号: 1007-9289(2020)04-0128-08

    基金信息

    宁波市“科技创新 2025”重大专项项目(2019B10100、2019B10094、2020Z045)；
    Supported by Ningbo Major Project of Science and Technology Innovation 2025 (2019B10100,2019B10094,2020Z045)；

    引用信息

    胡方勤, 曹振亚, 张青科, 等. 负偏压和本底真空度对 Al 膜表面形貌和耐蚀性能的影响[J]. 中国表面工程, 2020, 33(4): 128-135.

    HU F Q, CAO Z Y, ZHANG Q K, et al. Effects of negative bias voltage and base vacuum degree on surface morphology and corrosion resistance of Al coatings [J]. China Surface Engineering, 2020, 33(4): 128-135.

    稿件历史

    收稿日期: 2020-07-21

  • 参考文献

    • [1] SAGAWA M,FUJIMUL S,TOGAWA N,et al.New materi-al for permanent magnets on a base of Nd and Fe[J].Jour-nal of Applied Physics,1984,55(6):2083-2087.

    • [2] LI J L,MAO S D,SONG Z L,et al.TiN protective coating on NdFeB by DC magnetron sputtering [J].Advanced Mate-rials Research,2012,482-484:1130-1133.

    • [3] JACOBSON J,KIM A.Oxidation behavior of Nd-Fe-B mag-nets [J].Journal of Applied Physics,1987,(61):3763-3765.

    • [4] 李卫,朱明刚.高性能金属永磁材料的探索和研究进展 [J].中国材料进展,2009,28(9-10):62-73.LI W,ZHU M G.Research progress of high performance pet-allic permanent pagnetic materials [J].Materials China,2009,28(9-10):62-73(in Chinese).

    • [5] GURAPPA I.Corrosion characteristics of permanent magnets in acidic environments [J].Journal of Alloys and Com-pounds,2003,360(1-2):236-242.

    • [6] EDGLEY D S,BRETON J M L,STEYAERT S,et al.Char-acterisation of high temperature oxidation of NdFeB magnets [J].Journal of Magnetism and Magnetic Materials,1997,173(1/2):29-42.

    • [7] ALI A,AHMAD A,DEEN K M.Multilayer ceramic coating for impeding corrosion of sintered NdFeB magnets [J].Jour-nal of Rare Earths,2009,27(6):1003-1007.

    • [8] MAO S D,YANG H X,SONG Z L,et al.Corrosion behav-iour of sintered NdFeB deposited with an aluminium coating [J].Corrosion Science,2011,53(5):1887-1894.

    • [9] WU G,ZENG X,DING W,et al.Characterization of ceram-ic PVD thin films on AZ31 magnesium alloys[J].Applied Surface Science,2006,252(20):7422-7429.

    • [10] ENSINGER W,WOLF G K.Ion-beam-assisted coatings for corrosion protection studies[J].Materials Science and Engi-neering:A,1989,116:1-14.

    • [11] 胡芳,代明江,林松盛,等.循环氩离子轰击对磁控溅射铝膜结构和性能的影响[J].中国表面工程,2015,28(1):49-55.HU F,DAI M J,LIN S S,et al.Influences of cycles argon ion bombardment on structure and properties of Al films de-posited by magnetron sputtering[J].China Surface Engineer-ing,2015,28(1):49-55(in Chinese).

    • [12] MAO S D,YANG H X,LI J L,et al.Corrosion properties of aluminium coatings deposited on sintered NdFeB by ion-beam-assisted deposition [J].Applied Surface Science,2011,257:5581-5585.

    • [13] STIPPICH F,VERA E,SCHEERER H,et al.Corrosion properties of alumina coatings on steel and aluminum deposi-ted by ion beam assisted deposition[J].Surface & Coatings Technology,1998,98(1-3):997-1001.

    • [14] LANG F Q,YU Z M.The corrosion resistance and wear resist-ance of thick TiN coatings deposited by arc ion plating[J].Sur-face and Coatings Technology,2001,145(1-3):80-87.

    • [15] MA C B,CAO F H,ZHANG Z,et al.Electrodeposition of amorphous Ni-P coatings onto Nd-Fe-B permanent magnet substrates[J].Applied Surface Science,2006,253(4):2251-2256.

    • [16] CAO Z Y,DING X F,BAGHER R,et al.The deposition,microstructure and properties of Al protective coatings for Nd-FeB magnets by multi-arc ion plating[J].Vacuum,2017,142:37-44.

    • [17] 胡志华,华建杰,马冬威,等.烧结 Nd-Fe-B 磁体表面多弧离子镀 Ti(Al)N 镀层性能研究[J].稀土,2017,38(6):51-56.HU Z H,HUA J J,MA D W,et al.Study on properties of Ti(Al)N coatings on sintered Nd-Fe-B magnets by multiarc ion plating[J].Chinese Rare Earths,2017,38(6):51-56(in Chinese).

    • [18] LAMAS J S,LEROY W P,DEPLA D.Influence of target-substrate distance and composition on the preferential orienta-tion of yttria-stabilized zirconia thin films [J].Thin Solid Films,2012,520:4782-4785.

    • [19] CHIU K H,CHEN J H,CHEN H R,et al.Deposition and characterization of reactive magnetron sputtered aluminum ni-tride thin films for film bulk acoustic wave resonator [J].Thin Solid Films,2007,515(11):4819-4825.

    • [20] HONG S G,KWON S H,KANG S W,et al,Influence of substrate bias voltage on structure and properties of Cr-Mo-Si-N coatings prepared by a hybrid coating system[J].Surface & Coatings Technology,2008,203(5-7):624-627.

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