摘要
采用磁控溅射技术,以AISI304不锈钢为基体,通过在溅射过程中引入不同流量的N2,制备出不同程度N掺杂的Ta涂层,研究了少量N掺杂对Ta涂层微观结构、物相组成、力学及磨损性能的影响。结果表明,无N掺杂时,Ta涂层中的物相组成为α-Ta,晶粒粗大,(211)和(110)晶面竞争生长;N掺杂后涂层中的物相组成为TaN0.1,晶粒细小并呈(110)择优取向。少量N掺杂可以显著提高Ta涂层的硬度和弹性模量,并大幅度改善其抗磨损性能。涂层硬度和弹性模量的提高与晶粒细化、N原子固溶及涂层中存在的压应力有关。N掺杂后涂层的磨损机制由磨粒磨损向黏着磨损转变。
Tantalum coating attracts increasing attention in heat, corrosion and wear resistant applications today because of its high melting point, immunity to chemical attack and high toughness. Recently, tantalum has been considered a desirable candidate to replace electrodeposited(ED) chromium coating which is often used as protective coating against corrosion and wear. However, the wastes associated with ED chromium contain a well-known carcinogen, i.e. hexavalent chromium, which is a hazard to environment. In comparison, thick Ta coating is regarded as a more environmental and beneficial replacement. Tantalum coating is usually obtained by magnetron sputtering. However, tantalum exhibits two distinct crystalline phases. The body-centered cubic α-phase is the common phase in bulk metal and thermodynamically stable. α-Ta with good ductility and excellent mechanical properties is welcomed in most fields. β-Ta is a metastable phase with tetragonal crystalline lattice structure. The properties of β-Ta are not as advantageous as α-Ta because it is hard and brittle. The existence of β-Ta may compromise tantalum coating in adhesion, corrosion and wear resistance, hence, finding appropriate deposition conditions to obtain pure α-phase Ta coating has attracted a lot of interests. In previous work, pure α-phase Ta coating has been deposited by direct current magnetron sputtering when substrates were located in negative glow space. In this work, nitrogen was mixed in sputtering gases to deposit Ta coating with N interstitially dissolved on stainless steel. Effect of N on microstructure, mechanical and tribological performance of Ta coating was studied. Results indicated that when no nitrogen or very low flux of N2(l mL/s) were introduced in gas mixtures, α-phase Ta coating with coarse grains grew and revealed strong reflections of(211) and(110) diffraction peaks. When N2 flow rate reached to 5 mL/s, Ta coating with N interstitially dissolved was obtained and revealed grain refinement and(110) preferred orientation of TaN0.1 phase. Compared to α-phase Ta coating, N-doped tantalum coatings displayed excellent wear resistance for their high hardness and H3/E2 ratio(H—hardness, E—elastic modulus). The wear mechanism for α-Ta coating was abrasive wear, while that of N-doped Ta coating switched to adhesive wear.
引文
[1]Sopok S,Rickard C,Dunn S.Thermal-chemical-mechanical gun bore erosion of an advanced artillery system part one:Theories and mechanisms[J].Wear,2005,258:659
[2]Chen X J,Yan Q,Ma Q,Influence of the laser pre-quenched sub‐strate on an electroplated chromium coating/steel substrate[J].Ap‐pl.Surf.Sci.,2017,405:273
[3]Van Phuong N,Kwon S C,Lee J Y,et al.The effects of pH and polyethylene glycol on the Cr(III)solution chemistry and electro‐deposition of chromium[J].Surf.Coat.Technol.,2012,206:4349
[4]Quan C,He Y D.Properties of nanocrystalline Cr coatings pre‐pared by cathode plasma electrolytic deposition from trivalent chromium electrolyte[J].Surf.Coat.Technol.,2015,269:319
[5]Lee S L,Windover D,Audino M,et al.High-rate sputter deposited tantalum coating on steel for wear and erosion mitigation[J].Surf.Coat.Technol.,2002,149:62
[6]Maeng S M,Axe L,Tyson T A,et al.Corrosion behavior of mag‐netron sputteredα-Ta coatings on smooth and rough steel substrates[J].Surf.Coat.Technol.,2006,200:5717
[7]Hu X F,Xu Q.Preparation of tantalum by electro-deoxidation in a CaCl2-NaCl melt[J].Acta Metall.Sin.,2006,42:285(胡小锋,许茜.CaCl2-NaCl熔盐电脱氧法制备金属Ta[J].金属学报,2006,42:285)
[8]Matson D W,McClanahan E D,Lee S L,et al.Properties of thick sputtered Ta used for protective gun tube coatings[J].Surf.Coat.Technol.,2001,146-147:344
[9]Wang S,Xiong D S,Li J L,et al.Wear and erosion resistance prop‐erties of electroplating Ta coating in molten salt[J].China Surf.Eng.,2015,28(2):101(王升,熊党生,李建亮等.熔盐电镀钽及其耐磨损烧蚀性能[J].中国表面工程,2015,28(2):101)
[10]Myers S,Lin J L,Souza R M,et al.Theβtoαphase transition of tantalum coatings deposited by modulated pulsed power magne‐tron sputtering[J].Surf.Coat.Technol.,2013,214:38
[11]Lundin D,Sarakinos K.An introduction to thin film processing us‐ing high-power impulse magnetron sputtering[J].J.Mater.Res.,2012,27:780
[12]Lin J L,Moore J J,Sproul W D,et al.Effect of negative substrate bias on the structure and properties of Ta coatings deposited using modulated pulse power magnetron sputtering[J].IEEE Trans.Plas‐ma Sci.,2010,38:3071
[13]Ferreira F,Sousa C,Cavaleiro A,et al.Phase tailoring of tantalum thin films deposited in deep oscillation magnetron sputtering mode[J].Surf.Coat.Technol.,2017,314:97
[14]Frank S,Gruber P A,Handge U A,et al.In situ studies on the co‐hesive properties ofα-andβ-Ta layers on polyimide substrates[J].Acta Mater.,2011,59:5881
[15]Niu Y S,Chen M H,Wang J L,et al.Preparation and thermal shock performance of thickα-Ta coatings by direct current magne‐tron sputtering(DCMS)[J].Surf.Coat.Technol.,2017,321:19
[16]Lou B Y,Wang Y X.Effects of Mo content on the micro-structure and tribological properties of CrMoAlN films[J].Acta Metall.Sin.,2016,52:727(楼白杨,王宇星.Mo含量对CrMoAlN薄膜微观结构和摩擦磨损性能的影响[J].金属学报,2016,52:727)
[17]Han K C,Liu Y Q,Lin G Q,et al.Study on atomic-scale strength‐ening mechanism of transition-metal nitride MNx(M=Ti,Zr,Hf)films within wide composition ranges[J].Acta Metall.Sin.,2016,52:1601(韩克昌,刘一奇,林国强等.宽固溶区过渡金属氮化物MNx(M=Ti,Zr,Hf)硬质薄膜原子尺度强化机制研究[J].金属学报,2016,52:1601)
[18]Cui W F,Cao D,Qin G W.Microstructure and wear resistance of Ti/TiN multilayer films deposited by magnetron sputtering[J].Ac‐ta Metall.Sin.,2015,51:1531(崔文芳,曹栋,秦高悟.磁控溅射沉积Ti/TiN多层膜的组织特征及耐磨损性能[J].金属学报,2015,51:1531)
[19]Zhao S L,Zhang Z,Zhang J,et al.Microstructure and wear resis‐tance of TiAlZrCr/(Ti,Al,Zr,Cr)N gradient films deposited by multi-arc ion plating[J].Acta Metall.Sin.,2016,52:747(赵时璐,张震,张钧等.多弧离子镀TiAlZrCr/(Ti,Al,Zr,Cr)N梯度膜的微观结构与耐磨损性能[J].金属学报,2016,52:747)
[20]Raole P M,Narsale A M,Kothari D C,et al.Glancing-angle X-ray diffraction and X-ray photoelectron spectroscopy studies of nitrogen-implanted tantalum[J].Mater.Sci.Eng.,1989,A115:73
[21]Rogers J D,Sundaram V S,Kleiman G G,et al.High resolution study of the M45N67N67and M45N45N67Auger transitions in the 5d series[J].J.Phys.,1982,12F:2097
[22]Takano I,Isobe S,Sasaki T A,et al.Nitrogenation of various tran‐sition metals by N+2-ion implantation[J].Appl.Surf.Sci.,1989,37:25
[23]Stavrev M,Fischer D,Wenzel C,et al.Crystallographic and mor‐phological characterization of reactively sputtered Ta,Ta-N and TaN-O thin films[J].Thin Solid Films,1997,307:79
[24]Zhu S L,Wang F H,Wu W T.Theory and Application of Reactive Sputtering Kinetics[M].Beijing:China Science and Technology Press,1999:18(朱圣龙,王福会,吴维?.反应溅射动力学理论及应用[M].北京:中国科学技术出版社,1999:18)
[25]Pelleg J,Zevin L Z,Lungo S,et al.Reactive-sputter-deposited TiNfilms on glass substrates[J].Thin Solid Films,1991,197:117
[26]Wang X,Wang Z Y,Feng Z X,et al.Effect of N doping on micro‐structure,mechanical and tribological properties of V-Al-C coat‐ings[J].Acta Metall.Sin.,2017,53:709(王鑫,王振玉,冯再新等.N掺杂对V-Al-C涂层微观结构、力学及摩擦性能的影响[J].金属学报,2017,53:709)
[27]Xu S,Xu J,Munroe P,et al.Nanoporosity improves the damage tolerance of nanostructured tantalum nitride coatings[J].Scr.Ma‐ter.,2017,133:86
[28]Hakamada M,Nakamoto Y,Matsumoto H,et al.Relationship be‐tween hardness and grain size in electrodeposited copper films[J].Mater.Sci.Eng.,2007,A457:120
[29]Yamamoto T,Kawate M,Hasegawa H,et al.Effects of nitrogen concentration on microstructures of WNxfilms synthesized by ca‐thodic arc method[J].Surf.Coat.Technol.,2005,193:372
[30]Cheng G A,Han D Y,Liang C L,et al.Influence of residual stress on mechanical properties of TiAlN thin films[J].Surf.Coat.Tech‐nol.,2013,228:S328
[31]Yu L H,Dong H Z,Xu J H.Influence of C content on microstruc‐ture,mechanical properties and friction and wear properties of Ti‐WCN composite films[J].Acta Metall.Sin.,2014,50:1350(喻利花,董鸿志,许俊华.C含量对TiWCN复合膜微结构、力学性能和摩擦磨损性能的影响[J].金属学报,2014,50:1350)
[32]Aliofkhazraei M,Rouhaghdam A S.Fabrication of TiC/WC ultra hard nanocomposite layers by plasma electrolysis and study of its characteristics[J].Surf.Coat.Technol.,2010,205:S51