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通讯作者:

王泽松(1983—),男(汉),讲师,博士;研究方向:离子束材料改性和表面工程;E-mail:zswang531@163.com

中图分类号:TG174

文献标识码:A

文章编号:1007-9289(2020)06-0077-09

DOI:10.11933/j.issn.1007-9289.20200911001

参考文献 1
EHIASARIAN A P,MÜNZ W D,HULTMAN L,et al.High power pulsed magnetron sputtered CrNx films[J].Surface & Coatings Technology,2003,163(6):267-272.
参考文献 2
HERNÁNDEZ L C,PONCE L,FUNDORA A,et al.Nanohardness and Residual Stress in TiN Coatings[J].Materials,2011,4(12):929-940.
参考文献 3
李洪,杨鸿泰,林松盛,等.掺杂元素对TiAlN涂层结构及性能的影响[J].工具技术,2018,52(7):35-38.LI H,YANG H T,LIN S S,et al.Effect of elements on structure and properties of TiAlN coatings [J].Tool Engineering,2018,52(7):35-38(in Chinese).
参考文献 4
SUNDGRE J E.Structure and properties of TiN coatings[J].Thin Solid Films,1985,128(1-2):21-44.
参考文献 5
GARCÍA-GONZÁLEZ L,HERNÁNDEZ-TORRES J,GARCÍA-RAMÍREZ P J,et al.Structure and mechanical properties of TiBN coatings fabricated by dc reactive sputtering technique[J].Journal of Materials Processing Technology,2007,186(1/2/3):362-366.
参考文献 6
CHU K,SHEN Y G.Mechanical and tribological properties of nanostructured TiN/TiBN multilayer films [J].Wear,2008,265(3):516-524.
参考文献 7
HE Y,ZHOU J,WALSTOCK T,et al.Oxidation behaviour of PACVD TiBN coating at elevated temperatures[J].Surface & Coatings Technology,2009,204(5):601-609.
参考文献 8
刘丹,韩滨,闫少健,等.多弧离子镀制备 TiN/TiBN 纳米复合涂层的结构和性能[J].中国表面工程,2014,27(5):102-108.LIU D,HAN B,YAN S J,et al.Structure and mechanical properties of TiN/TiB nanocomposite coatings deposited by multi-arc plasma deposition[J].China Surface Engineering,2014,27(5):102-108(in Chinese).
参考文献 9
LIN B Z,WANG L L,WAN Q,et al.Low friction-coefficient TiBCN nanocomposite coatings prepared by cathode arc plasma deposition[J].Plasma Science & Technology,2015,17(3):221-227.
参考文献 10
CAO Y Z,HU Z J,YAN L L,et al.Self-forming TiBN nanocomposite multilayer coating prepared by pulse cathode arc method[J].Nanoscale Research Letters,2016,11(1):349-349.
参考文献 11
KAINZ C,SCHALK N,TKADLETZ M,et al.Microstructure and mechanical properties of CVD TiN/TiBN multilayer coatings[J].Surface & Coatings Technology,2019:311-319.
参考文献 12
ZHU Lihui,SONG Cheng,NI Wangyang,et al.Effect of 10% Si addition on cathodic arc evaporated TiAlSiN coatings [J].Transactions of Nonferrous Metals Society of China,2016,26:1638-1646.
参考文献 13
MA Q S,LI L H,XU Y,et al.Effect of Ti content on the microstructure and mechanical properties of TiAlSiN nanocomposite coatings [J].International Journal of Refractory Metals & Hard Materials,2016,59:114-120.
参考文献 14
HANS,M,SCHNEIDER J M.On the chemical composition of TiAlN thin films-comparison of ion beam analysis and laser-assisted atom probe tomography with varying laser pulse energy[J].Thin Solid Films,2019,688:137251.
参考文献 15
PARK I W,CHOI S R,JU H S,et al.Deposition and mechanical evaluation of superhard Ti-Al-Si-N nanocomposite films by a hybrid coating system [J].Thin Solid Films,2004,447(4):443-448.
参考文献 16
MADAN A,KIM I W,CHENG S C,et al.Stabilization of cubic AlN in epitaxial AlN/TiN superlattices[J].Physical Review Letters,1997,78(9):1743-1746.
参考文献 17
HAROLD P K,LEROY E A.X-Ray diffraction procedures:For polycrystalline and amorphous materials [ M ].2nd ed.Weinheim,Germany:Wiley-VCH,1974.
参考文献 18
ZHAO J,WANG X,CHEN Z Y,et al.Overall energy model for preferred growth of TiN films during filtered arc deposition[J].Journal of Physics D,1997,30(1):5-12.
参考文献 19
XPS Home in the Measurement services division of the national institute of standards and technology(NIST)[EB/OL] ∥ https:∥srdata.nist.gov/xps/ElmComposition.aspx.
参考文献 20
NEIDHARDT J,CZIGÁNY Z,SARTORY B,et al.Nanocomposite Ti-B-N coatings synthesized by reactive arc evaporation[J].Acta Materialia,2006,54(16):4193-4200.
参考文献 21
HARSANI M,SAHUL M,ZACKOVA P,et al.Study of cathode current effect on the properties of CrAlSiN coatings prepared by LARC[J].Vacuum,2017,139:1-8.
参考文献 22
牛宝林,陈汪林,刘书媛,等.氮气分压对AlCrTiSiN超晶格涂层微观结构及力学性能的影响[J].中国表面工程,2015,28(2):45-52.NIU B L,CHEN W L,LIU S Y,et al.Effects of partial pressure of N2 on microstructure and mechanical properties of AlCrTiSiN superlattice coatings[J].China Surface Engineering,2015,28(2):45-52(in Chinese).
参考文献 23
MUSIL J,JIROUT M.Toughness of hard nanostructured ceramic thin films[J].Surface & Coatings Technology,2007,201(9):5148-5152.
参考文献 24
WANG Z S,TIAN C X,TOLSTOGOUZOV A,et al.Microstructure and rutherford backscattering spectrometry of hard/lubricant Mo-Ti-Al-N multilayered coatings prepared by multi-arc ion plating at low substrate rotation[J].Coatings,2020,10(2):1-15.
参考文献 25
FENG C J,Hu S L,JIANG Y F,et al.Effects of Si content on microstructure and mechanical properties of TiAlN/Si3N4-Cu nanocomposite coatings [J].Applied Surface Science,2014,320:689-698.
参考文献 26
薛钰芝,林纪宁,周玉梅,等.氮分压对TiN离子镀层影响的研究[J].大连交通大学学报,1998,19(1):25-29.XUE Y Z,LIN J N,ZHOU Y M,et al.The influence of divided pressure of N2 on TiN ion plating[J].Journal of Dalian Jiaotong University,1998,19(1):25-29(in Chinese).
参考文献 27
朱晓飞,颜家伟,张广平.金属多层膜的强度及界面强化能力研究进展[J].中国科学:技术科学,2012,42(6):635-642.ZHU X F,YAN J W,ZHANG G P.Research progress on strength and interfacial strengthening ability of metal multilayers [J].Chinese Science:Technical Science,2012,42(6):635-642(in Chinese).
参考文献 28
肖白军.AlCrN/AlTiSiN 纳米多层刀具涂层的制备及其性能研究[D].广州:广东工业大学,2019.XIAO B J.Fabrication and properties of AlCrN/AlTiSiN nano-layered coatings on cutting tools [ D ].Guangzhou:Guangdong University of Technology,2019(in Chinese).
目录contents

    摘要

    为应对高速干式切削、工磨具行业对新型防护涂层的需求,制造高硬度、耐摩擦磨损的纳米复合涂层具有巨大的市场前景。 采用阴极多弧离子镀技术,在不同的工作气压下用 TiB2 和 TiAlSi 合金靶作为阴极蒸发靶材,在硬质合金衬底上分别沉积了 TiBN,TiAlSiN 涂层和 TiBN/ TiAlSiN 多层涂层。 借助于 XRD、 XPS、 SEM、 AFM 和 HRTEM 对涂层的成分、形貌及微观结构进行表征分析。 并用纳米压痕硬度计和球盘式摩擦测试仪分别研究了涂层的硬度和摩擦磨损性能。 研究结果表明:TiBN/ TiAlSiN 涂层呈现一种非晶相包裹纳米多晶相的微观结构形态,工作气压越高,涂层表面越趋于光滑;涂层在 1. 0 Pa 工作气压下涂层显微硬度值达到 38 GPa;在 2. 0 Pa 的工作气压下,涂层显微硬度值约 34 GPa,摩擦因数低于 0. 29。 与 TiBN 和 TiAlSiN 涂层相比,TiBN/ TiAlSiN 纳米多层涂层的机械、摩擦学性能更加优越,这为应用在干式切削、磨削工具领域的硬质润滑多层涂层的制备与研究指明了一条方向。

    Abstract

    The novel nanocomposite coatings have become the most promising protective materials due to their high hardness and antiwear properties for the requirements of high-speed dry cutting and grinding tool industry. The monolithic TiBN, TiAlSiN and TiBN/ TiAlSiN nano-multilayer coatings were deposited on hard alloy matrixes at various working pressures by tuning N2 flow rates using a cathodic multi-arc ion plating system wherein the composite TiB2 and TiAlSi targets were selected as evaporative cathodes. The microstructure, composition, and morphologies were analyzed by XRD, XPS, SEM, AFM and HRTEM, respectively. Nano-indentation and ball-on-disc friction tester were used to investigate the mechanical and tribological properties of the coatings. Results show that TiBN/ TiAlSiN coatings possess a typical structure where the nanocrystals are imbedded in the amorphous layers. The higher the working pressure, the smoother the surface of TiBN/ TiAlSiN coatingsis. The maximum microhardness value can reach 38 GPa at 1. 0 Pa, while a microhardness of approximately 34 GPa with the lowest coefficient of friction of 0. 29 is obtained for TiBN/ TiAlSiN coatings fabricated at 2. 0 Pa as compared to the monolithic TiBN and TiAlSiN coatings with the hardness beneath 28 GPa and coefficient of friction over 0. 50. The mechanical and tribology performance is superior to the monolithic TiBN or TiAlSiN coatings, which can pave the way for fabricating the hard / lubricant nanosized multilayered coatings in the field of dry-cutting and grinding tools.

  • 0 引言

  • 自20世纪60年代以来,二元CrN和TiN硬质薄膜一直占据着传统刀具、磨具等工业涂层领域的重要地位,但在高速干式切削、硬膜压铸等特殊工磨具产业的应用上略显不足[1-3]。因为机械制造业的飞速发展,用于机械加工的工具从普通金属基材开始向超硬、耐热、耐腐蚀、自润滑等功能增强型材料转变,所以对覆盖其表面的保护性涂层的要求越来越苛刻。 TiN涂层的显微硬度一般在15~25GPa,常温和高温下的干摩擦因数为0.6~0.9,温度高于400℃ 时就有明显氧化的迹象[4]。为此,向CrN, TiN等二元涂层的结构中添加B、Si、 Al及其他元素使其成为多元涂层, 或者构建纳米复合结构体系,如多层膜、超晶格结构都能显著改善其物理化学性能、机械及摩擦学性能,从而增加工磨具基材的使用寿命。

  • 多元氮化钛基复合涂层是超硬纳米复合涂层的代表,目前关于B、Si掺杂氮化钛涂层的研究表明,掺杂可以明显改善涂层的物理机械性能。富含B元素的TiBN涂层或TiBN/TiN纳米复合涂层具有典型的BN非晶相包裹TiN多晶相的复合微观结构,与TiN涂层相比,有更高的硬度、更卓越的热稳定性和耐摩擦磨损性[5-8]。有学者利用多种物理气相沉积(Physical vapor deposition, PVD)技术制备TiBN涂层,当工作气压较低时涂层硬度达到30GPa,摩擦因数低至0.2~0.4 [9-10]。 Kainz等[11] 利用热化学气相沉积(Chemical vapor deposition, CVD)技术合成不同调制周期的TiBN/TiN多层膜, 当调制周期为200nm时,多层膜的硬度值达到31GPa±2GPa, 断裂韧性值显著高于单一的TiN和TiBN膜。另一种备受关注的是Si,Al共掺杂氮化钛基多元涂层,由于该类涂层中形成了亚稳态( Ti,Al) N固溶相和nc-( Ti,Al) N/a-Si3N4 复合相的缘故, TiAlSiN涂层的硬度、抗氧化性和摩擦学性能均得到了极大提高。 Zhu等[12]研究TiAlSiN涂层指出Si的摩尔百分比浓度为10%时,涂层中形成了nc-(Ti,Al,Si) N/a-Si3N4 纳米复合结构,其硬度达到34.7GPa。 Ma等[13] 通过调整反应磁控溅射制备的TiAlSiN纳米复合涂层中Ti和Si的原子浓度,使涂层的硬度值超过66GPa。

  • 显而易见,TiBN涂层具有较低的摩擦因数, TiAlSiN涂层容易获得高硬度值,只需选用高纯的TiB2 陶瓷靶和TiAlSi合金靶作为阴极蒸发靶材,结合阴极多弧离子镀工艺沉积速率高、行星式靶架公转-自转切换自如的优势,就有可能在绝大数金属合金基片上制备出高硬度、低摩擦因数的TiBN/TiAlSiN纳米多层硬质涂层。该复合涂层每个亚层可能形成非晶包裹多晶TiN,或者纳米晶固溶于多晶TiN的微观结构,而两亚层的调制周期比、界面结构均也能极大地影响复合涂层的整体性能,这为应用于干式切屑、磨屑领域的金属/陶瓷、陶瓷/陶瓷复合涂层的制备与研究提供参考价值。

  • 1 试验

  • 1.1 涂层制备

  • 选用纯度均为99.99%的TiB2(原子比Ti ∶B=0.33 ∶0.67)陶瓷靶和TiAlSi(原子比Ti ∶Al ∶ Si=0.6 ∶0.3 ∶ 0.1) 合金靶材,有效避免了CVD技术中用到的剧毒、危险性硼烷和硅烷等气体的使用,安全可靠且原子蒸发效率高。两种阴极靶均为直径120mm,厚度50mm的圆柱形块体,对称地安装在尺寸为540mm×300mm×400mm的真空腔室内壁两侧,单靶与基片的最小中心距离为225mm。直径为10mm,厚度为5mm的单面抛光型YT15硬质合金(成分WC-TiC-Co)基片装配在样品底盘支架上,整个样品底盘能进行一重公转,其上的支架可实现二重自转,基片的公转-自转模式能同时进行,也能自由切换,涂层沉积系统结构原理图如图1所示。

  • 为了去除基片表面污染物,首先将用于此次试验的硬质合金试片分别置于热碱性溶液、丙酮溶液中各超声清洗10min,然后用去离子水反复漂洗,最后用干燥氮气吹干后装载到样品支架上。沉积之前,用涡轮分子泵、罗茨泵和旋片机械泵组成的真空机组将腔室本底真空度抽至3.0×10-3 Pa,基片温度保持在300℃。沉积过程主要分为两步:① 离子轰击清洗:为移除基片表面氧化层和污染物,调节脉冲偏压至-800V,设置占空比为80%,向真空腔内通入氩气,调节流量使气压稳定在2.0Pa,保持Ar +离子轰击基片30min;② 沉积目标涂层:设置基片偏压为-200V, TiB2 和TiAlSi靶电流分别为70A和65A, 通入N2,沉积时间为40min。调节Ar/N2 流量比,逐渐增大N2 流量使腔室工作气压为1.0、1.5、2.0、 2.5和3.0Pa。另外,在保证沉积工艺参数相同的情况下,维持工作气压为2.0Pa,分别换用阴极Ti金属靶、TiB2 靶和TiAlSi靶在硬质合金基片上分别制备了TiN涂层、TiBN涂层和TiAlSiN涂层, 以便进行对比研究。 TiBN/TiAlSiN纳米复合涂层的沉积参数如表1所示。

  • 图1 多弧离子镀沉积系统示意图

  • Fig.1 Schematic diagram of the deposition system

  • 表1 沉积TiBN/TiAlSiN复合涂层的工艺参数

  • Table1 Deposition parameters of TiBN/TiAlSiN multilayered coatings

  • 1.2 结构表征与性能测试

  • (1) 采用型号Bruker D8advanced的X-射线衍射仪(XRD)检测涂层的物相结构,射线源为 λ=0.154 06nm的Cu Kα 射线。相位角2θ 设置从20°到80°,扫描步长为0.04°。

  • (2) 采用型号为FEI Sirion IMP的场发射扫描电镜观察样品的表面和截面的形貌,最高电子加速电压20kV。

  • (3) 采用型号SPM-9500J3的原子力显微镜(AFM)探针来获取样品表面的粗糙度。

  • (4) 采用型号XSAM800KRATOS的X-射线光电子能谱( XPS) 分析涂层组成元素的化学状态和化学成分。测量的主要参数为: 1253.6eV,150W的Mg Kα 激发;数据的分析,首先用C 1s( E=284.6eV)对光谱数据进行校正,再用XPS Peak4.1软件对光谱数据进行分峰和拟合。

  • (5) 采用型号JEOL JEM 2010的高分辨透射电镜(HRTEM)来观察样品的微结构。

  • (6) 采用MTS G200型纳米压痕仪来测量涂层的显微硬度和弹性模量,选择连续刚度测试(Continuous stiffness measurement, CSM) 模式。在测试中,使用一个圆头半径为60nm的三向三棱锥压头,并加载一个适中的载荷值,设置压入样品的最大压深为0.1 μm,并保持加载时间20s。载荷系统和位移系统的分辨率分别为50nN和0.04nm。测试结果取5次测量的平均值。

  • (7) 采用MS-T3000型球盘测试仪测试涂层的摩擦磨损的性能。摩擦接触材料为直径为3mm的WC-Co陶瓷小球,球盘载荷为10N,以0.02m/s的滑动速度在连续测试60min,测试温度和相对湿度分别为28℃和75%。

  • 2 结果与讨论

  • 2.1 TiBN/TiAlSiN涂层的微结构

  • 图2 显示了在不同工作气压下制备的TiBN/TiAlSiN复合涂层的X射线衍射图样。为了定位涂层中的结晶相, TiN和TiBN的XRD衍射图样也呈现在图中。从图中可以看出涂层结构主要由面心立方(fcc)的多晶TiN(111)、TiN(200)和TiN(220)构成。随着工作气压从1.0Pa升高到3.0Pa,TiN(111)的衍射峰相对强度先升高后降低,TiN(200)对应的衍射峰增强,同时TiN(220) 也逐渐出现。图中几乎所有的衍射峰展宽,可能是两方面原因造成的。 ①浓度低于50at.%的Al在TiN晶体结构中可能会形成亚稳态TiAlN固溶体,将衍射峰展宽[14];②B、 Si、Al原子的引入, TiN晶粒的生长受到抑制,晶格畸变引起微观应力变化明显,边界效应加剧[15-16]。以小衍射角时的择优取向TiN(111)衍射峰位2θ=36.68°为对象, 通过优化后的Scherrer方程式 Dhkl=0.943λ/(βhkl × cosθ) [17](λ 是X射线波长,βhkl 是某一衍射峰的半高宽,θ 是衍射角) 计算,TiN涂层的TiN(111)和不同气压下的TiBN/TiAlSiN复合涂层晶粒尺寸分别为14.16、12.03、11.54、 9.79、10.79和9.35nm。由此可见,与TiN相比, 由于Al,Si和B原子掺入到TiN晶格中,晶粒尺寸会减小;随着工作气压的升高,复合涂层中的择优取向生长方向的晶粒尺寸减小,说明高气压沉积的涂层晶粒细化明显。工作气压偏高时,为释放过多的应变能,到达样品表面的沉积离子逐渐从高势能面(111) 向低势能面(200) 和(220) 扩散[18]

  • 图2 不同工作气压下涂层的XRD图谱

  • Fig.2 XRD patterns of TiBN/TiAlSiN multilayers at various working pressures

  • 在图3中,分别给出了不同工作气压下的样品XPS全谱和核能级谱。从图3( a)看,涂层中元素的主谱线都出现,也没有Mg Kα2激发的卫星峰存在,涂层中出现C、O元素,说明表面有C污染并被氧化,这在一般PVD镀膜工艺中很常见,结合能约1000eV处对应的峰群可能是C元素的伴随俄歇电子谱所致。样品的Ti2p光谱由454.4,456.1和458.2eV这3个分峰拟合而成, 分别对应Ti-B,Ti-N和Ti-O的化学态[19],可以确定涂层中存在TiN和表面氧化的TiO2。在B1s谱拟合分峰中, 位于结合能191.0eV对应BN [9-10],而结合能187.5eV处并未出现TiB2 峰。在N1s能谱中,一个高强度分峰位397.2eV对应TiAlN,另一能量398.3eV与Si3N4 相对应[20]。 Si2p 能谱中显示仅有一个主要的Si-N键峰位于102.2eV处,表明涂层的Si元素以Si3N4 形式存在[20],这与N1s谱分析的结果相吻合。 Al2p 能谱中孤立单峰位于73.9eV,对应AlN [12-13]。另外, 我们通过XPS逐层扫描方式测量了不同气压条件下沉积纳米多层涂层表面的化学成分,如表2所示。样品表面原子含量最高的是Ti和N,并且随着气压升高,Ti原子含量增加,Al和Si元素的含量变化不大,B元素在3.0Pa含量(原子数分数) 仅为2.38%,说明大的氮气流量可能导致TiB2 阴极靶中毒。如果将工作气压为1.0~2.5Pa条件下沉积涂层样品的平均原子组分表示为Ti22.48-Al7.34-B 15.72-Si2.59-N 49.82(原子数分数/%), 涂层中约有原子数分数为2%的C和O。 Al/Si的比值为2.83,接近于TiAlSi阴极靶中Al/Si原子浓度比值3,说明PVD涂层中原子的化学计量比与阴极靶成分密切相关[21]

  • 图4 显示了不同工作气压下沉积的TiBN/TiAlSiN涂层的表面3D-AFM图像。

  • 扫描探针测量样品表面局域面积为5 μm× 5 μm, 可得到涂层的表面均方根粗糙度值(RMS),列于表2中。当工作气压从1.0Pa增加到3.0Pa时,涂层表面上岛丘状大尺寸颗粒数目减少,RMS值从11.73nm降低到1.36nm,这主要是因为随着气压的升高,等离子体密度增大, 离子对基片的表面溅射能力增强,能较大程度地平滑表面。结合表2中XPS测量的B含量骤降可知,3.0Pa气压条件下TiB2 阴极靶中毒,引起到达样品表面的大尺寸颗粒数目减少,但仍有大量来自于TiAlSi阴极靶的沉积离子引起样品表面的溅射刻蚀效应, 所以表面粗糙度进一步降低。

  • 图5 展示了工作气分压1.5、2.0和2.5Pa条件下沉积的TiBN/TiAlSiN涂层的SEM表面形貌图5(a)~(c)和截面图5(d)~(f)。从表面形貌图5(a)~(c)看,涂层表面存在一些微小金属液滴(Microdroplet)、针孔( Pinhole)、熔坑(Melting crater),这些是电弧离子镀沉积过程经常出现的现象,其表面缺陷密度与沉积工艺参数密切相关[22]。同时,随着工作气压的增加,可以观察到表面大颗粒数目减少,这是由于增加反应气体的分压,等离子体密度增大,金属粒子直接沉积到基片表面形成液滴的几率变小,也有可能是表面的金属大颗粒物被后续入射的沉积离子二次溅射所致。由涂层的截面图片可测量涂层的厚度,见表2。随着工作气压从1.0Pa增加到2.5Pa,沉积过程中涂层的沉积速率逐渐升高,这是由于等离子体密度增加,单位时间内到达表面的沉积离子数目增多,表现为涂层物理厚度的增加。但3.0Pa时由于TiB2 阴极靶中毒造成沉积速率下降,涂层物理厚度减小。

  • 图3 TiBN/TiAlSiN纳米复合涂层的XPS能谱

  • Fig.3 XPS spectra of TiBN/TiAlSiN nanocomposite coatings deposited at some workingpressures

  • 为了进一步研究TiBN/TiAlSiN多层涂层的微观织构,用HRTEM对样品的截面进行了检测。图6是TiBN/TiAlSiN多层涂层在工作气压2.0Pa条件下放大倍数分别为 × 500 00( 图6( a)) 和 × 500 000(图6(b))下的HRTEM图像。从图6(a) 中可以清楚地观察到典型的纳米多层结构,图中不规则形状围成的区域可能是非晶或是不同取向晶粒生长造成的衍射衬度差异造成的。图6(b)中,将局部图像再次放大后标记A、B、C的子晶粒中的晶面间距分别为0.3350、0.2410和0.2085nm,与XRD测试结果中的TiN(111)、(200)和(220)基本相符合。图6(b)右上角的选区电子衍射图样中多晶环对应的面间距 d111d200d220 与图2XRD图样中面心立方的TiN或TiAlN的面间距基本一致。根据TiBN和TiAlSiN在TEM明场像中的质量衬度差异,图中亮条纹对应TiAlSiN层,暗条纹对应TiBN层,结合试验设计的基片旋转模式,形成交替子层的原因是样品在沉积过程中不断旋转、交替面向处于相对位置的两阴极靶造成的。由于沉积工艺参数的波动影响,涂层中这种明暗相间的条纹分布不均匀[23-24], 图6(a)中标注的TiBN/TiAlSiN双分子层厚度估算分别为7.04和7.80nm,图6(b) 中双层厚度(Bilayer thickness)为8.32nm,分别由1.22nm厚的TiAlSiN子层和7.10nm厚的TiBN子层组成。

  • 图4 不同工作气压下TiBN/TiAlSiN复合涂层的3DAFM图像

  • Fig.4 Three-dimensional AFM images of TiBN/TiAlSiN multilayered coatings at different working pressures

  • 图5 不同工作气压下TiBN/TiAlSiN涂层的SEM表面形貌图和截面形貌

  • Fig.5 Surface morphological and cross-sectional SEM images of TiBN/TiAlSiN coatings at different working pressures

  • 表2 不同工作气压沉积的TiBN/TiAlSiN多层涂层的化学成分和物理参数

  • Table2 Chemical compositions by XPS and physical parameters of multilayered coatings at various pressures

  • 图6 工作气压2.0Pa条件下沉积的涂层的HRTEM图像

  • Fig.6 HRTEM micrographs of TiBN/TiAlSiN coatings deposited at 2.0Pa

  • 2.2 涂层的机械性能

  • 2.2.1 涂层的显微硬度和弹性模量

  • 图7 给出了不同工作气压下沉积涂层的纳米硬度和杨氏弹性模量。从图7可以看出,与TiBN、TiAlSiN涂层相比,低气压条件下沉积的复合涂层的硬质较高。随着工作气压的增加,涂层的纳米硬度和弹性模量值降低。工作气压为1.0Pa时,涂层的纳米硬度值高达38GPa。这跟以往研究报道的电弧离子镀沉积单层涂层随氮气流量或分压升高呈现先增加后减少的趋势不同。原因有以下两点:① 低工作气压时,氮气不足,涂层样品中可能有不饱和Ti2N相生成,其硬度比TiN相硬度高[25];② 从图6( b) 中可以看出,TiBN子层中的fcc-TiN和TiSiAlN子层中的fcc-TiAlN形成同结构共格外延生长,而低气压时TiBN/TiAlSiN纳米多层膜具有较小的调制周期厚度,因此TiBN和TiAlSiN两调制层中晶格错配造成的小周期交变应变场使得涂层硬度升高[26-27]。另外,从图2可以看出,低工作气压下制备的涂层中以应变能为主导的TiN(111)相含量明显高于以表面能为主导的TiN(200)相[18],说明1Pa工作气压下多层涂层整体的应变能最低,其硬度最高。当气压升高,涂层沉积速率提高,双分子层厚度变大,交变应变场周期变大,硬度降低。值得一提的是,试验中制备的多层涂层样品中Si含量低于3at.%可能是造成涂层的硬度达不到其他研究人员报道的40GPa以上硬度的陶瓷涂层的原因[12-13,28]

  • 图7 不同工作气压下(1.0~3.0Pa)TiBN/TiAlSiN多层涂层和TiBN及TiAlSiN涂层(2Pa)的硬度和弹性模量

  • Fig.7 Hardness and Young’ s elastic modulus of TiBN/TiAlSiN multi-layer coatings fabricated at 1.0-3.0Pa and TiBN, TiAlSiN coatings at 2.0Pa

  • 2.2.2 涂层的摩擦因数和磨损率

  • 室温下不同工作气压下的TiBN/TiAlSiN涂层的摩擦因数(Coefficient of friction, COF) 和磨损率数值如图8所示。当工作气压从1.0Pa增加到2.0Pa时,COF值逐渐降低至0.29,同时磨损率降至4.3×10-7 mm 3/(N·m)。而且气压为3.0Pa时,涂层的COF值最小为0.273,这与表2中RMS值的变化趋势基本一致,说明涂层表面粗糙度越低,表面越光滑,摩擦因数越低,磨损率也越低。而且,所有TiBN/TiAlSiN纳米多层涂层样品的COF值及磨损率均低于TiBN和TiAlSiN涂层,说明TiBN/TiAlSiN纳米多层硬质涂层与单层涂层相比具有更加优异的耐磨性。

  • 图8 不同工作气压下(1.0~3.0Pa)TiBN/TiAlSiN多层涂层和TiBN及TiAlSiN涂层(2Pa)的室温摩擦因数和磨损率

  • Fig.8 COF and wear rate of TiBN/TiAlSiN multi-layer coatings fabricated at 1.0-3.0Pa and TiBN, TiAlSiN coatings at 2.0Pa

  • 3 结论

  • 以TiB2 和TiAlSi合金靶作为阴极靶原料,通过多弧离子镀技术,在不同的工作气压下,成功地在硬质合金基片上合成了TiBN/TiAlSiN纳米多层涂层,主要可以得到以下结论。

  • (1) 涂层中主要晶相由面心立方结构TiN(111)、TiN(200)和TiN(220)构成,随着工作气压的增加,涂层生长表现为应变能低的晶向TiN(111)逐渐向表面能主导的TiN(200)演化,高衍射相位角处涂层中垂直于TiN(220)方向的晶粒结晶度变好。

  • (2) XPS结果显示,涂层中面心立方结构的AlN与TiN形成TiAlN固溶体、B、Si元素以BN和Si3N4 纳米晶或非晶形式存在。工作气压从1.0Pa升高到2.5Pa,涂层中的元素含量变化不大,但在气压为3.0Pa时存在靶中毒造成B含量骤降。 SEM和AFM共同证实由于工作气压的升高,等离子体密度增大,涂层表面会变得光滑。

  • (3) 通过HRTEM图像分析,在2.0Pa条件下沉积的涂层中双分子层厚度为8.32nm,且TiBN和TiAlSiN亚层的厚度分别为7.10和1.22nm。两亚层中的面心立方结构的TiN和TiAlN在界面处具有共格生长现象,造成小调制周期的交变应力场变化,这也是涂层具有较高硬度的主要原因。与TiBN和TiAlSiN涂层相比,综合考虑涂层硬度与磨擦学性能参数,在2.0Pa的工作气压下沉积的TiBN/TiAlSiN纳米多层涂层不仅具有很高的硬度,还具有良好的抗摩擦磨损性能,为应用在高速干切削、磨具领域复合硬质耐磨涂层材料的PVD制备工艺提供参考价值。

  • 参考文献

    • [1] EHIASARIAN A P,MÜNZ W D,HULTMAN L,et al.High power pulsed magnetron sputtered CrNx films[J].Surface & Coatings Technology,2003,163(6):267-272.

    • [2] HERNÁNDEZ L C,PONCE L,FUNDORA A,et al.Nanohardness and Residual Stress in TiN Coatings[J].Materials,2011,4(12):929-940.

    • [3] 李洪,杨鸿泰,林松盛,等.掺杂元素对TiAlN涂层结构及性能的影响[J].工具技术,2018,52(7):35-38.LI H,YANG H T,LIN S S,et al.Effect of elements on structure and properties of TiAlN coatings [J].Tool Engineering,2018,52(7):35-38(in Chinese).

    • [4] SUNDGRE J E.Structure and properties of TiN coatings[J].Thin Solid Films,1985,128(1-2):21-44.

    • [5] GARCÍA-GONZÁLEZ L,HERNÁNDEZ-TORRES J,GARCÍA-RAMÍREZ P J,et al.Structure and mechanical properties of TiBN coatings fabricated by dc reactive sputtering technique[J].Journal of Materials Processing Technology,2007,186(1/2/3):362-366.

    • [6] CHU K,SHEN Y G.Mechanical and tribological properties of nanostructured TiN/TiBN multilayer films [J].Wear,2008,265(3):516-524.

    • [7] HE Y,ZHOU J,WALSTOCK T,et al.Oxidation behaviour of PACVD TiBN coating at elevated temperatures[J].Surface & Coatings Technology,2009,204(5):601-609.

    • [8] 刘丹,韩滨,闫少健,等.多弧离子镀制备 TiN/TiBN 纳米复合涂层的结构和性能[J].中国表面工程,2014,27(5):102-108.LIU D,HAN B,YAN S J,et al.Structure and mechanical properties of TiN/TiB nanocomposite coatings deposited by multi-arc plasma deposition[J].China Surface Engineering,2014,27(5):102-108(in Chinese).

    • [9] LIN B Z,WANG L L,WAN Q,et al.Low friction-coefficient TiBCN nanocomposite coatings prepared by cathode arc plasma deposition[J].Plasma Science & Technology,2015,17(3):221-227.

    • [10] CAO Y Z,HU Z J,YAN L L,et al.Self-forming TiBN nanocomposite multilayer coating prepared by pulse cathode arc method[J].Nanoscale Research Letters,2016,11(1):349-349.

    • [11] KAINZ C,SCHALK N,TKADLETZ M,et al.Microstructure and mechanical properties of CVD TiN/TiBN multilayer coatings[J].Surface & Coatings Technology,2019:311-319.

    • [12] ZHU Lihui,SONG Cheng,NI Wangyang,et al.Effect of 10% Si addition on cathodic arc evaporated TiAlSiN coatings [J].Transactions of Nonferrous Metals Society of China,2016,26:1638-1646.

    • [13] MA Q S,LI L H,XU Y,et al.Effect of Ti content on the microstructure and mechanical properties of TiAlSiN nanocomposite coatings [J].International Journal of Refractory Metals & Hard Materials,2016,59:114-120.

    • [14] HANS,M,SCHNEIDER J M.On the chemical composition of TiAlN thin films-comparison of ion beam analysis and laser-assisted atom probe tomography with varying laser pulse energy[J].Thin Solid Films,2019,688:137251.

    • [15] PARK I W,CHOI S R,JU H S,et al.Deposition and mechanical evaluation of superhard Ti-Al-Si-N nanocomposite films by a hybrid coating system [J].Thin Solid Films,2004,447(4):443-448.

    • [16] MADAN A,KIM I W,CHENG S C,et al.Stabilization of cubic AlN in epitaxial AlN/TiN superlattices[J].Physical Review Letters,1997,78(9):1743-1746.

    • [17] HAROLD P K,LEROY E A.X-Ray diffraction procedures:For polycrystalline and amorphous materials [ M ].2nd ed.Weinheim,Germany:Wiley-VCH,1974.

    • [18] ZHAO J,WANG X,CHEN Z Y,et al.Overall energy model for preferred growth of TiN films during filtered arc deposition[J].Journal of Physics D,1997,30(1):5-12.

    • [19] XPS Home in the Measurement services division of the national institute of standards and technology(NIST)[EB/OL] ∥ https:∥srdata.nist.gov/xps/ElmComposition.aspx.

    • [20] NEIDHARDT J,CZIGÁNY Z,SARTORY B,et al.Nanocomposite Ti-B-N coatings synthesized by reactive arc evaporation[J].Acta Materialia,2006,54(16):4193-4200.

    • [21] HARSANI M,SAHUL M,ZACKOVA P,et al.Study of cathode current effect on the properties of CrAlSiN coatings prepared by LARC[J].Vacuum,2017,139:1-8.

    • [22] 牛宝林,陈汪林,刘书媛,等.氮气分压对AlCrTiSiN超晶格涂层微观结构及力学性能的影响[J].中国表面工程,2015,28(2):45-52.NIU B L,CHEN W L,LIU S Y,et al.Effects of partial pressure of N2 on microstructure and mechanical properties of AlCrTiSiN superlattice coatings[J].China Surface Engineering,2015,28(2):45-52(in Chinese).

    • [23] MUSIL J,JIROUT M.Toughness of hard nanostructured ceramic thin films[J].Surface & Coatings Technology,2007,201(9):5148-5152.

    • [24] WANG Z S,TIAN C X,TOLSTOGOUZOV A,et al.Microstructure and rutherford backscattering spectrometry of hard/lubricant Mo-Ti-Al-N multilayered coatings prepared by multi-arc ion plating at low substrate rotation[J].Coatings,2020,10(2):1-15.

    • [25] FENG C J,Hu S L,JIANG Y F,et al.Effects of Si content on microstructure and mechanical properties of TiAlN/Si3N4-Cu nanocomposite coatings [J].Applied Surface Science,2014,320:689-698.

    • [26] 薛钰芝,林纪宁,周玉梅,等.氮分压对TiN离子镀层影响的研究[J].大连交通大学学报,1998,19(1):25-29.XUE Y Z,LIN J N,ZHOU Y M,et al.The influence of divided pressure of N2 on TiN ion plating[J].Journal of Dalian Jiaotong University,1998,19(1):25-29(in Chinese).

    • [27] 朱晓飞,颜家伟,张广平.金属多层膜的强度及界面强化能力研究进展[J].中国科学:技术科学,2012,42(6):635-642.ZHU X F,YAN J W,ZHANG G P.Research progress on strength and interfacial strengthening ability of metal multilayers [J].Chinese Science:Technical Science,2012,42(6):635-642(in Chinese).

    • [28] 肖白军.AlCrN/AlTiSiN 纳米多层刀具涂层的制备及其性能研究[D].广州:广东工业大学,2019.XIAO B J.Fabrication and properties of AlCrN/AlTiSiN nano-layered coatings on cutting tools [ D ].Guangzhou:Guangdong University of Technology,2019(in Chinese).

  • 参考文献

    • [1] EHIASARIAN A P,MÜNZ W D,HULTMAN L,et al.High power pulsed magnetron sputtered CrNx films[J].Surface & Coatings Technology,2003,163(6):267-272.

    • [2] HERNÁNDEZ L C,PONCE L,FUNDORA A,et al.Nanohardness and Residual Stress in TiN Coatings[J].Materials,2011,4(12):929-940.

    • [3] 李洪,杨鸿泰,林松盛,等.掺杂元素对TiAlN涂层结构及性能的影响[J].工具技术,2018,52(7):35-38.LI H,YANG H T,LIN S S,et al.Effect of elements on structure and properties of TiAlN coatings [J].Tool Engineering,2018,52(7):35-38(in Chinese).

    • [4] SUNDGRE J E.Structure and properties of TiN coatings[J].Thin Solid Films,1985,128(1-2):21-44.

    • [5] GARCÍA-GONZÁLEZ L,HERNÁNDEZ-TORRES J,GARCÍA-RAMÍREZ P J,et al.Structure and mechanical properties of TiBN coatings fabricated by dc reactive sputtering technique[J].Journal of Materials Processing Technology,2007,186(1/2/3):362-366.

    • [6] CHU K,SHEN Y G.Mechanical and tribological properties of nanostructured TiN/TiBN multilayer films [J].Wear,2008,265(3):516-524.

    • [7] HE Y,ZHOU J,WALSTOCK T,et al.Oxidation behaviour of PACVD TiBN coating at elevated temperatures[J].Surface & Coatings Technology,2009,204(5):601-609.

    • [8] 刘丹,韩滨,闫少健,等.多弧离子镀制备 TiN/TiBN 纳米复合涂层的结构和性能[J].中国表面工程,2014,27(5):102-108.LIU D,HAN B,YAN S J,et al.Structure and mechanical properties of TiN/TiB nanocomposite coatings deposited by multi-arc plasma deposition[J].China Surface Engineering,2014,27(5):102-108(in Chinese).

    • [9] LIN B Z,WANG L L,WAN Q,et al.Low friction-coefficient TiBCN nanocomposite coatings prepared by cathode arc plasma deposition[J].Plasma Science & Technology,2015,17(3):221-227.

    • [10] CAO Y Z,HU Z J,YAN L L,et al.Self-forming TiBN nanocomposite multilayer coating prepared by pulse cathode arc method[J].Nanoscale Research Letters,2016,11(1):349-349.

    • [11] KAINZ C,SCHALK N,TKADLETZ M,et al.Microstructure and mechanical properties of CVD TiN/TiBN multilayer coatings[J].Surface & Coatings Technology,2019:311-319.

    • [12] ZHU Lihui,SONG Cheng,NI Wangyang,et al.Effect of 10% Si addition on cathodic arc evaporated TiAlSiN coatings [J].Transactions of Nonferrous Metals Society of China,2016,26:1638-1646.

    • [13] MA Q S,LI L H,XU Y,et al.Effect of Ti content on the microstructure and mechanical properties of TiAlSiN nanocomposite coatings [J].International Journal of Refractory Metals & Hard Materials,2016,59:114-120.

    • [14] HANS,M,SCHNEIDER J M.On the chemical composition of TiAlN thin films-comparison of ion beam analysis and laser-assisted atom probe tomography with varying laser pulse energy[J].Thin Solid Films,2019,688:137251.

    • [15] PARK I W,CHOI S R,JU H S,et al.Deposition and mechanical evaluation of superhard Ti-Al-Si-N nanocomposite films by a hybrid coating system [J].Thin Solid Films,2004,447(4):443-448.

    • [16] MADAN A,KIM I W,CHENG S C,et al.Stabilization of cubic AlN in epitaxial AlN/TiN superlattices[J].Physical Review Letters,1997,78(9):1743-1746.

    • [17] HAROLD P K,LEROY E A.X-Ray diffraction procedures:For polycrystalline and amorphous materials [ M ].2nd ed.Weinheim,Germany:Wiley-VCH,1974.

    • [18] ZHAO J,WANG X,CHEN Z Y,et al.Overall energy model for preferred growth of TiN films during filtered arc deposition[J].Journal of Physics D,1997,30(1):5-12.

    • [19] XPS Home in the Measurement services division of the national institute of standards and technology(NIST)[EB/OL] ∥ https:∥srdata.nist.gov/xps/ElmComposition.aspx.

    • [20] NEIDHARDT J,CZIGÁNY Z,SARTORY B,et al.Nanocomposite Ti-B-N coatings synthesized by reactive arc evaporation[J].Acta Materialia,2006,54(16):4193-4200.

    • [21] HARSANI M,SAHUL M,ZACKOVA P,et al.Study of cathode current effect on the properties of CrAlSiN coatings prepared by LARC[J].Vacuum,2017,139:1-8.

    • [22] 牛宝林,陈汪林,刘书媛,等.氮气分压对AlCrTiSiN超晶格涂层微观结构及力学性能的影响[J].中国表面工程,2015,28(2):45-52.NIU B L,CHEN W L,LIU S Y,et al.Effects of partial pressure of N2 on microstructure and mechanical properties of AlCrTiSiN superlattice coatings[J].China Surface Engineering,2015,28(2):45-52(in Chinese).

    • [23] MUSIL J,JIROUT M.Toughness of hard nanostructured ceramic thin films[J].Surface & Coatings Technology,2007,201(9):5148-5152.

    • [24] WANG Z S,TIAN C X,TOLSTOGOUZOV A,et al.Microstructure and rutherford backscattering spectrometry of hard/lubricant Mo-Ti-Al-N multilayered coatings prepared by multi-arc ion plating at low substrate rotation[J].Coatings,2020,10(2):1-15.

    • [25] FENG C J,Hu S L,JIANG Y F,et al.Effects of Si content on microstructure and mechanical properties of TiAlN/Si3N4-Cu nanocomposite coatings [J].Applied Surface Science,2014,320:689-698.

    • [26] 薛钰芝,林纪宁,周玉梅,等.氮分压对TiN离子镀层影响的研究[J].大连交通大学学报,1998,19(1):25-29.XUE Y Z,LIN J N,ZHOU Y M,et al.The influence of divided pressure of N2 on TiN ion plating[J].Journal of Dalian Jiaotong University,1998,19(1):25-29(in Chinese).

    • [27] 朱晓飞,颜家伟,张广平.金属多层膜的强度及界面强化能力研究进展[J].中国科学:技术科学,2012,42(6):635-642.ZHU X F,YAN J W,ZHANG G P.Research progress on strength and interfacial strengthening ability of metal multilayers [J].Chinese Science:Technical Science,2012,42(6):635-642(in Chinese).

    • [28] 肖白军.AlCrN/AlTiSiN 纳米多层刀具涂层的制备及其性能研究[D].广州:广东工业大学,2019.XIAO B J.Fabrication and properties of AlCrN/AlTiSiN nano-layered coatings on cutting tools [ D ].Guangzhou:Guangdong University of Technology,2019(in Chinese).

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