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作者简介:

卞凯,男,1995年出生,硕士研究生。主要研究方向为绿色高效精密加工与智能制造。E-mail:kaibian123@foxmail.com;

唐思文(通信作者),男,1980年出生,博士,教授,博士研究生导师。主要研究方向为绿色高效精密加工与智能制造、刀具技术。E-mail:siw_tang@hnust.edu.cn

中图分类号:TG174

DOI:10.11933/j.issn.1007−9289.20210512002

参考文献 1
HERNANDEZ M T,AGUILERA L D,PONCE A,et al.Tribological performance of TiN and TiCN coatings on a working tool steel[J].Journal of Mechanical Science and Technology,2018,32(8):3659-3666.
参考文献 2
MARINA V,ALEXEY V,NIKOLAY A,et al.Improvement of the performance properties of cutting tools using the multilayer composite wear-resistantcoatings based on nitrides of Cr,Mo,Zr,Nb,and Al[J].Materials Today:Proceedings,2021,38(4):1421-1427.
参考文献 3
汪鹏,许昌庆,蔡飞,等.多弧离子镀TiAlSiN梯度涂层制备及切削性能[J].中国表面工程,2019,32(2):34-43.WANG Peng,XU Changqing,CAI Fei,et al.Preparation and machining properties of tialsin gradient coating by multi-arc ion plating[J].China Surface Engineering,2019,32(2):34-43.(in Chinese)
参考文献 4
SHARMA V,KUMAR M,SHUKLA V N.Tribobehaviour of nano-structured coatings deposited by various techniques:A review[J].Materials Today:Proceedings,2021,44(6):4097-4101.
参考文献 5
SKORDARIS G,BOUZAKIS K D,CHARALAMPOUS P,et al.Brittleness and fatigue effect of mono-and multilayer PVD films on the cutting performance of coated cemented carbide inserts[J].CIRP Annals,2014,63(1):93-96.
参考文献 6
张云乾,丁彰雄,范毅.HVOF 喷涂纳米 WC-12Co 涂层的性能研究[J].中国表面工程,2005,18(6):25-29.ZHANG Yunqian,DING Zhangxiong,FAN Yi.Study on the performance of HVOF sprayed nano-WC-12Co coating[J].China Surface Engineering,2005,18(6):25-29.(in Chinese)
参考文献 7
RABINOVICH G S,YAMAMOTO K,KOVALEV A I,et al.Wear behavior of adaptive nano-multilayered TiAlCrN/NbN coatings under dry high performance machining conditions[J].Surface & Coatings Technology,2008,202(10):2015-2022.
参考文献 8
KOEHELER J S.Attempt to design a strong solid[J].Physical Review B,1970,2(2):547-551.
参考文献 9
吴雁,王冰,肖礼军,等.Ti-Al-Si-N 多层梯度涂层的微观结构及力学性能研究[J].表面技术,2021,50(2):232-237.WU Yan,WANG Bin,XIAO Lijun,et al.Study on the microstructure and mechanical properties of Ti-Al-Si-N multilayer gradient coatings[J].Surface Technology,2021,50(2):232-237.(in Chinese)
参考文献 10
SOTOVA C,SITNIKOV N,BUBLIKOV J,et al.Influence of thickness of multilayer composite nano-structured coatings on tool life of metal-cutting tool[J].The European Physical Journal Conferences,2019,224(2):11-15.
参考文献 11
孙磊,熊计,杨天恩.金属陶瓷及硬质合金表面 CVD/PVD 涂层的摩擦与切削性能[J].中国表面工程,2019,32(6):45-55.SUN Lei,XIONG Ji,YANG Tianen.Friction and cutting performance of CVD/PVD coating on cermet and cemented carbide surface[J].China Surface Engineering,2019,32(6):45-55.(in Chinese)
参考文献 12
PARSONS G N,GEORGE S M,KNEZ M.Progress and future directions for atomic layer deposition and ALD-based chemistry[J].Mrs Bulletin,2011,36(11):865-871.
参考文献 13
SONG G,TAN D Q.Atomic layer deposition for polypropylene film engineering—A review[J].Macromolecular Materials and Engineering,2020,305(6):68-92.
参考文献 14
HU Y,LU J,FENG H.Surface modification and functionalization of powder materials by atomic layer deposition:A review[J].RSC Advances,2021,11(20):11918-11942.
参考文献 15
SHAN C X,HOU X,Choy K L.Corrosion resistance of TiO2 films grown on stainless steel by atomic layer deposition[J].Surface & Coatings Technology,2008,202(11):2399-2402.
参考文献 16
WADULLAH H M,AJEEL S A,ABBASS M K.Synthesis and characterization of nanocoatings thin films by atomic layer deposition for medical applications[J].IOP Conference Series:Materials Science and Engineering,2019,518(3):2057-2064.
参考文献 17
FUSCO M,OLDHAM C,PARSONS G.Investigation of the corrosion behavior of atomic layer deposited Al2O3/TiO2 nanolaminate thin films on copper in 0.1 m NaCl[J].Materials,2019,12(4):672-696.
参考文献 18
上海市金属切削技术协会.金属切削手册[M].2 版.上海:上海科学技术出版社,1982.Shanghai Metal Cutting Technology Association.Metal cutting manual[M].2ed.Shanghai:Shanghai Science and Technology Press,1982.(in Chinese)
参考文献 19
瞿鑫.光学涂层对磁性金属的颜色和磁光效应的影响[D].北京:首都师范大学,2014.QU Xin.The influence of optical coating on the color and magneto-optical effect of magnetic metals[D].Beijing:Capital Normal University,2014.(in Chinese)
参考文献 20
ZHA X,CHEN F,JIANG F,et al.Correlation of the fatigue impact resistance of bilayer and nanolayered PVD coatings with their cutting performance in machining Ti6Al4V[J].Ceramics International,2019,45(12):14704-14717.
参考文献 21
DAROONPARVAR M,YAJID M A,YUSOF N M,et al.Fabrication and properties of triplex NiCrAlY/nano Al2O3-13%TiO2/nano TiO2 coatings on a magnesiumalloy by atmospheric plasma spraying method[J].Journal of Alloys and Compounds.2015,645(10):450-466.
参考文献 22
李佩真,唐思文,孙林,等.基于原子沉积法的纳米 Al2O3 涂层微织构刀具刀-屑界面间摩擦因数研究[J].现代制造工程,2020,(10):26-32.LI Peizhen,TANG Siwen,SUN Lin,et al.Research on the friction coefficient between the tool-chip interface of nano-Al2O3 coating micro-textured tool based on atomic deposition method[J].Modern Manufacturing Engineering,2020,(10):26-32.(in Chinese)
参考文献 23
MUTHUKUMAR M,YADAV A,BOBJI M S.Wear characteristics of nanoporous alumina and copper fillednanocomposite coatings[J].Wear,2020,462(20):96-105.
参考文献 24
庞俊忠,牛苜森,黄晓斌,等.高速铣削淬硬钢时的切屑形态试验研究[J].机械设计与制造,2021(1):152-155.PANG Junzhong,NIU Musen,HUANG Xiaobin,et al.Experimental study on chip morphology during high-speed milling of hardened steel[J].Machinery Design & Manufacture,2021(1):152-155.(in Chinese)
目录contents

    摘要

    采用原子层沉积技术(ALD)在 200 ℃低温条件下将纳米 Al2O3 / TiO2多层涂层沉积在硬质合金刀具表面。利用扫描电镜 SEM、划痕测试仪和三向测力仪以及数控机床等设备,对不同形式的纳米 Al2O3 / TiO2 多层涂层刀具的涂层-基体结合力和切削性能等进行研究。结果表明,基于原子层沉积技术低温制备的纳米多层涂层刀具的涂层-基体结合强度高;涂层层数、 涂层沉积顺序及涂层层厚比对纳米多层涂层刀具的切削力有不同程度的影响;纳米多层涂层刀具更适合高速切削,当切削速度大于 2.33 m / s 时,纳米多层涂层刀具的切削力和摩擦因数呈下降趋势,表现出良好的切削性能,其中双层纳米涂层刀具的切削性能更好;在高速切削时,纳米多层涂层刀具表面摩擦因数比普通未涂层硬质合金刀具低,纳米 Al2O3 / TiO2 多层涂层能够有效改善刀具的黏结磨损,减少刀-屑粘黏现象和烫伤现象,能够改善刀具表面的耐磨损性能。

    Abstract

    Nano-Al2O3 / TiO2 multilayer coatings are deposited on the surface of cemented carbide tools at a low temperature of 200 ℃ by atomic layer deposition (ALD). The adhesion of coating-substrate and the cutting performance of different nano-Al2O3 / TiO2 multilayer coating tools are studied by SEM, and three-scratch tester dynamometer and CNC machine tools. The results show that the adhesion of coating-substrate of the nano-multilayer coating tool prepared at low temperature based on atomic layer deposition technology is high. The number of coating layers, coating deposition sequence and coating layer thickness ratio have varying degrees of influence on the cutting force of the nano-multilayer coating tool. The nano-multilayer coating tool is more suitable for high-speed cutting. When the cutting speed is more than 2.33 m / s, the cutting force and friction factor of the nano-multilayer coating tool show a downward trend and good cutting performance. The cutting performance of the double-layer nano-coated tool is better. In high-speed cutting, the surface friction factor of the nano-multilayer coating tool is lower than that of the ordinary uncoated cemented carbide tool, the nano-Al2O3 / TiO2 multilayer coating can effectively reduce the bonding wear of the tool and the phenomenon of tool-chip sticking and "scalding", which can improve the wear resistance of the tool surface.

  • 0 前言

  • 刀具表面涂层技术是众多学者公认能够提高刀具切削性能的有效手段之一[1-2]。近年来,高速干式切削技术的快速发展,对刀具涂层的耐磨性、热稳定性和抗氧化性等性能提出更高的要求[3]。相比传统涂层,纳米涂层拥有更高的致密度、更好的力学性能和更长的使用寿命[4-6]。而在纳米涂层中,纳米多层涂层的性能一般要比纳米单层涂层的性能更好[7]。KOEHLER[8]最先提出多层设计的概念,即利用具有不同弹性模量的材料实现相互交替沉积,提高涂层的性能。这种多层结构可以综合组分层优点,使得涂层的韧性、硬度、抗高温氧化性等性能优于单层涂层[9]。SOTOVA等[10]通过无涂层刀具、TiAlN涂层刀具和纳米Ti-TiN-(TiCrAl)N/Zr-ZrN-(ZrCrNbAl)N多层涂层刀具车削45#钢试验发现,在高切削速度下,纳米多层涂层刀具的切削性能优势尤为明显。

  • 目前,制备纳米多层涂层的方法主要有物理气相沉积(Physical vapor deposition,PVD)、化学气相沉积(Chemical vapor deposition,CVD)等,但是PVD技术主要存在涂层-基体的结合强度不够高的问题,CVD技术普遍存在由于制备温度过高而影响刀具基体性能的问题[11]。原子层沉积技术(Atomic layer deposition,ALD)是化学气相沉积技术的一支,其制备原理是将气相前驱体交替脉冲引入反应器中,并以单原子层薄膜的形式逐层沉积到基体表面。 ALD薄膜涂层生长的基础是交替饱和的气相-固相表面反应,涂层和基体间没有明显的过渡层,涂层制备过程中会发生化学吸附反应从而达到沉积效果,因此每个循环周期生长的薄膜都只有一个单原子层[12]。ALD沉积温度一般在300℃以下,比普通CVD技术的更低且涂层厚度的控制精度可达到纳米级,制备出的纳米涂层有更好的均匀性、保形性、阶梯覆盖率[13]。原子层沉积技术中应用最为广泛的材料是Al2O3和TiO2 [14]。SHAN等[15]采用原子层沉积技术在不锈钢基体上沉积TiO2 涂层,结果发现TiO2 涂层完全覆盖基体,TiO2涂层对不锈钢具有良好的保护作用。WADULLAH等[16]利用原子层沉积技术在钴铬合金和硅晶片基体上制备了25nm和50nm的Al2O3、TiO2 和Al2O3/TiO2涂层并对涂层形貌进行了表征。结果表明,在250℃时采用ALD能够均匀沉积涂层且涂层质量好,无缺陷和微裂纹。 FUSCO等[17]研究了原子层沉积技术(ALD)制备的纳米Al2O3/TiO2多层涂层对铜的保护作用,发现每层5nm的Al2O3 和TiO2交替层组成的涂层是最佳的耐蚀性涂层。以上研究表明,利用ALD可以在基体表面低温沉积出质量和性能良好的纳米Al2O3/TiO2多层涂层。

  • 本文通过原子层沉积技术在200℃条件下制备了9种纳米Al2O3/TiO2 多层刀具涂层,并开展划痕和直角干切削等试验,以探究不同的纳米Al2O3/TiO2 多层涂层的性能及其对刀具切削性能的影响机理,为纳米Al2O3/TiO2多层涂层在刀具领域的应用提供理论支撑。

  • 1 试验

  • 1.1 纳米多层涂层的制备

  • 为了系统研究纳米多层涂层的力学性能和切削性能,一共制备了9种不同类别的涂层形式,详见表1。表中涂层命名方式如下:NT代表纳米涂层, A6T1中A代表Al2O3涂层,T代表TiO2涂层,数字6和1分别代表所占比例。

  • 表1 纳米多层涂层的形式

  • Table1 Forms of nano multilayer coating

  • 采用ALD技术在硬质合金刀具表面低温沉积纳米Al2O3/TiO2 多层涂层,刀具为山特维克9.62mm×9.62mm×3.18mm方形车刀片,前角0°、后角11°、刃倾角0°。制备纳米Al2O3 和纳米TiO2 涂层的气相-固相表面反应方程见式(1)和式(2):

  • 2AlCH33+3H2O200CAl2O3+6CH4
    (1)
  • TiOCHCH324+2H2O200CTiO2+4CH32CHOH
    (2)
  • 制备纳米Al2O3/TiO2 涂层的具体流程如下。

  • (1)前处理过程。首先,在超声波清洗器中用丙酮溶液将刀具清洗600s,除去有机杂质。之后,利用无水乙醇洗去丙酮残留物;然后,在去离子水中利用超声波将刀具表面的静电荷清洗干净,最后用氮气将刀具表面吹干。

  • (2)纳米涂层的制备。① 将ALD反应腔抽真空至50Pa以下,恒温200℃约30min,将前处理后的刀具放入腔室;② 利用载气将前驱体(Al2O3 的前驱体三甲基铝(Trimethylaluminum,TMA), TiO2 的前驱体为钛酸四异丙酯(Tetraisopropyl titanate, TTIP)送入反应腔,使其在刀具表面发生自吸附反应,充分反应后抽出反应副产物CH4气体,清扫腔室。③ 再利用载气通入去离子水至反应腔,使其与表面的TMA或TTIP基团产生化学反应形成单层纳米Al2O3 或TiO2 涂层,清扫腔室。④ 记连续的步骤②和③为第一预设次数,重复第一预设次数,即可获得理想厚度的纳米Al2O3/TiO2涂层。

  • 1.2 微观表征及力学性能测试

  • 采用美国J.A.Woollam公司生产的光谱椭偏仪 (J.A.Woollam Alpha-SE)测量纳米Al2O3/TiO2 多层涂层的厚度,激光的波长为390~890nm,入射角为70°,涂层厚度见表1。采用莱州华银试验仪器有限公司生产的维氏硬度计测量不同涂层刀具的硬度,纳米涂层刀具的硬度见表1。采用美国Bruker公司生产的原子力显微镜,表征纳米涂层的形貌。采用日本日立公司生产的SU3500扫描电子显微镜,观察测量刀具表面以及切屑表面。采用瑞士CSM仪器公司生产的MCT划痕测试仪,测试涂层-基体的结合力,划针材质为金刚石,划针圆角半径为50 μm,移动速度为3mm/min,声发信号采集频率为20Hz。

  • 1.3 切削试验

  • 通过直角干车削试验研究NT和PT的切削性能。从切削力、切屑形态、刀具表面磨损形态等方面,综合分析纳米多层涂层对刀具切削性能的影响机理。通过查阅切削加工手册确定直角干切削半精加工的切削参数[18],切削速度 v 分别取60、100、 140、180、220m/min,进给量 f 取0.1mm/r,背吃刀量 ap取0.5mm。

  • 2 结果分析与讨论

  • 2.1 纳米多层涂层刀具的表面形貌

  • 制备的9种纳米多层涂层刀具如图1所示。图1中从左到右的刀具排列顺序对应表1从上至下的涂层设计顺序。从宏观来看,不同纳米复合涂层刀具的颜色差异很大,表现为不同深浅的银灰、棕褐、藏蓝、蓝绿、暗黄等颜色,这主要是由不同厚度的纳米涂层的折射率不同引起的颜色减反现象[19]

  • 图1 基于ALD技术制备的纳米涂层刀具

  • Fig.1 Nano-coated tool prepared based on ALD technology

  • 图2 为原子力显微镜拍摄的NTA0T1、 NTA10T1、NTA10T1A10纳米涂层刀具的涂层形貌。从图中可以看出,涂层已经均匀覆盖刀具表面,涂层表面无破损点与滴状气泡。这说明涂层制备过程中,涂层内部产生的应力较小,涂层质量良好,基于ALD的纳米涂层低温沉积的效果良好。

  • 图2 纳米Al2O3/TiO2涂层微观形貌

  • Fig.2 Micro morphology of nano-Al2O3/TiO2 coating

  • 2.2 涂层-基体结合力

  • 涂层基体结合力由划痕试验获得,图3为声发信号、载荷力与涂层破裂位置关系图,通过对比三者关系可得出涂层-基体的结合力。图3中 abc 三点分别对应涂层脱落的三个阶段的起点,a 点为塑性变形阶段起点,b 点为开始脱落阶段起点,c 点为严重脱落阶段起点,记点 b 对应的载荷为涂层-基体脱落的临界载荷力。由图3可知各刀具对应的临界载荷分别为12.32N (NTA0T1)、8.41N (NTA10T1)和10.87N (NTA10T1A10)。与ZHA等[20]利用PVD技术制备的结合强度良好的纳米TiSiN/TiAlN多层涂层相比,纳米Al2O3/TiO2多层涂层的结合强度与之相当。由此可见,基于ALD低温制备的纳米多层涂层能够沉积在硬质合金刀具表面,且涂层-基体结合强度较高。

  • 图3 声发信号、载荷力与涂层破裂位置关系图

  • Fig.3 Relation diagram of acoustic signal, load force and coating rupture position

  • 2.3 纳米多层涂层刀具的切削性能

  • 2.3.1 纳米多层涂层刀具的切削力

  • 选取不同层数的纳米多层涂层刀具,研究涂层层数对刀具切削力的影响。不同切削速度下PT(普通刀具)、NTA0T1(单层)、NTA1T1(双层)、 NTA1T1A1(三层)的切削力如图4所示。

  • 图4 不同层数的NT的切削力

  • Fig.4 Cutting force of NT with different layers

  • 从图4中可以看出,当切削速度 v ≤140m/min时,PT的切削力小于NT。NTA1T1A1在不同切削速度下的切削力均大于NTA0T1和NTA1T1的切削力,其原因是NTA1T1A1最外层为纳米Al2O3,其减摩性能不如纳米TiO2,导致切削力较大。当切削速度 v ≥100m/min时,PT的切削力不断上升。当切削速度 v ≥140m/min时,NT的切削力呈下降趋势。当切削速度 v ≥180m/min时,NT的切削力小于PT。在切削速度 v=220m/min时,NT的切削力达到最小值,其中NTA1T1(双层)的切削力最小,这是因为纳米Al2O3 起到耐磨的效果,且与纳米TiO2 产生协同效应,提高涂层的致密性。可见, NT在高速切削状态下对刀具切削力的降低效果最为明显;在高速切削时,外层为纳米TiO2、内层为纳米Al2O3 的涂层的切削性能比单层纳米TiO2 涂层的切削性能好。

  • 在涂层层数和涂层层厚比一致的条件下,不同涂层沉积顺序的刀具切削力如图5所示。由图5可知,NTA1T1的切削力要明显小于NTT1A1,在220m/min的切削速度下,最外层为TiO2 的纳米涂层刀具切削阻力比最外层为Al2O3 的纳米涂层刀具低14%以上。这是由于TiO2 减摩层和Al2O3 耐磨层具有一定的协同性,并且沉积顺序对协同性会产生较大影响,当TiO2 在最外层时才会产生最佳的协同效果。DAROONPARVAR等[21]在制备纳米TiO2/Al2O3 多层涂层时发现了这一现象,当外层为纳米TiO2涂层、内层为纳米Al2O3涂层时会产生协同效应,这是因为TiO2 粒子填补了内部的Al2O3 耐磨层的空隙,提高了涂层的致密性。由此可见,外层为纳米TiO2 涂层、内层为纳米Al2O3 涂层时,有利于降低纳米Al2O3/TiO2 多层涂层刀具的切削力。

  • 图5 不同沉积顺序的NT的切削力

  • Fig.5 Cutting force of NT with different deposition sequences

  • 在涂层沉积顺序、涂层层数一致的条件下,不同涂层层厚比的刀具切削力如图6所示。当 v ≥ 140m/min时,NTA6T1和NTA10T1的切削力明显小于NTA1T1的切削力。在 v=180m/min时, NTA6T1比NTA1T1的切削力降低5.8%。在 v=220m/min时NTA10T1比NTA1T1的切削力降低9.2%。同时发现当 v ≥140m/min时,NTA10T1的切削力迅速下降,降幅明显高于NTA6T1,到 v=220m/min时,NTA10T1的切削力已经比NTA6T1降低8.9%。这说明在高速切削时,当内层为纳米Al2O3、外层为纳米TiO2 时,Al2O3 和TiO2 的层厚比比较大有利于降低纳米Al2O3/TiO2 多层涂层刀具的切削力。产生这种现象的原因可能是当外层为纳米TiO2 时,内层的纳米Al2O3越厚,在高速切削时纳米涂层能够产生的纳米磨损颗粒越多,将滑动摩擦转化为滚动摩擦的效果越好,降低了刀屑间摩擦因数[22]

  • 图6 不同层厚比的NT的切削力

  • Fig.6 Cutting force of NT with different layer thickness ratio

  • 2.3.2 纳米多层涂层刀具的摩擦因数

  • 刀具的摩擦因数是评价刀具切削性能的一个重要的指标。不同切削速度下NT和PT的摩擦因数如图7所示。PT的摩擦因数随着切削速度的增加而增加,当 v ≤140m/min时,随着切削速度的增加,摩擦因数的增幅明显,当 v >140m/min时摩擦因数增幅较小。而NT的摩擦因数变化是先增后减,在 v ≥100m/min时摩擦因数大幅度降低,到 v >140m/min时摩擦因数开始普遍小于PT,与NT在 v ≥140m/min时,切削力呈下降趋势这一结论相符合,验证了NT更适合用于高速切削。当 v ≥140m/min时,纳米双层涂层的摩擦因数小于纳米单层涂层的摩擦因数。在 v ≥180m/min时NT的摩擦因数全部小于PT,在 v=220m/min时各NT取得最低摩擦因数。最外层为TiO2 减摩层的刀具摩擦因数在 v >140m/min时的降幅明显大于最外层为Al2O3耐磨层的刀具。

  • 图7 不同切削速度下各刀具的摩擦因数

  • Fig.7 The friction factor of each tool at different cutting speeds

  • 2.4 涂层减摩抗磨机理分析

  • 使用扫描电子显微镜( Scanning electron microscope,SEM)分别观察了PT、NTA10T1在不同切削速度下的刀具磨损形貌,结果如图8、9所示。

  • 从图8、9中可以看出,随着切削速度 v 的增加,PT的磨损现象越来越严重。低速切削过程中,PT表面的粘黏物很少。高速切削时,PT基体硬度较低、耐磨性不足,导致切削热不断增加,高温粘黏物开始黏附在刀具表面,加剧了刀具的黏结磨损。随着切削速度的增加,NT的黏结磨损现象却呈现先变多后变少的趋势。在 v=220m/min的切削速度下,NT的磨损最小,NT的减摩耐磨性能得到了明显的提高。一方面是因为纳米涂层中的Al2O3 耐磨层提高了刀具表面的耐磨性,TiO2 减摩层降低了切削时的摩擦因数。另一方面,可能是由于纳米多层涂层表面产生纳米磨损颗粒将滑动摩擦转变成滚动-滑动摩擦,降低了摩擦因数。 MUTHUKUMAR等[23]也发现了这一现象,通过研究纳米复合镀层的摩擦磨损行为发现,摩擦表面会产生磨损颗粒保护摩擦层,降低摩擦因数,并延长纳米多层涂层的寿命。

  • 图8 不同切削速度下PT的磨损形貌

  • Fig.8 Wear morphology of PT at different cutting speeds

  • 图9 不同切削速度下NTA10T1的磨损形貌

  • Fig.9 Wear morphology of NTA10T1at different cutting speeds

  • 切屑形态被不少研究者认为是一种记录诸多切削加工信息的最直观载体[24]。不同切削速度(从上往下依次为220、180、140、100、 60m/min)下PT和NTA10T1切屑的宏观形貌如图10所示。从图中可以看出,NTA10T1比PT切屑的规律更加明显。NTA10T1切屑为连续周期性的弯曲带状切屑,说明稳定的切削过程更利于断屑。而PT切屑在高速切削条件下,翘曲周期不稳定,说明高速切削状态下PT没有NT稳定。

  • 刀具在高温高压的连续干切削条件下,不仅前刀面会产生严重的黏结磨损现象,高温氧化物及细小颗粒同样也会黏附在切屑接触表面。因此,切屑也是揭示和反映刀具摩擦磨损现象的重点研究对象。图11和图12分别是不同状态下PT的切屑表面和NTA10T1的切屑表面。

  • 图10 不同切削速度下的切屑宏观形貌

  • Fig.10 Macro morphology of chip at different cutting speeds

  • 从图11中可以看出,随着切削速度增加,PT切屑表面的黑色烫伤纹逐渐减少,表面黏结物却越来越多。NTA10T1所产生的切屑没有明显的黑色 “烫伤”现象,切屑表面的黏附现象也有明显改善。从图12可以发现,高速切削过程中,NTA10T1切屑表面粗糙度高,没有明显瑕疵。首先,这可能是由于NT表面的摩擦因数小,减少了摩擦生热。纳米多层涂层较低的热传导率也改善了切屑-刀具间的热分布,使得刀-屑接触表面的温度得到有效释放,从而减少刀-屑粘黏现象。其次,脱落的纳米颗粒在刀具表面可能还形成光滑的纳米保护膜,刀屑间的摩擦、挤压效应进一步减弱,减小切削过程中切屑表面的压强,使得切屑表面的氧化物不易粘附在切屑表面,极大地减少了粘黏现象。

  • 图11 不同状态的PT切屑表面

  • Fig.11 Chip surface of the PT at different states

  • 图12 不同状态的NTA10T1切屑表面

  • Fig.12 Chip surface of the NTA10T1at different states

  • 3 结论

  • (1)利用原子层沉积技术能够在刀具表面低温制备出力学性能良好的纳米Al2O3/TiO2 多层涂层,其涂层-基体结合强度较高。

  • (2)纳米Al2O3/TiO2多层涂层刀具适合高速切削,当切削速度 v> 140m/min时,纳米涂层刀具的切削力和摩擦因数呈下降趋势。

  • (3)在高速切削条件下,外层为纳米TiO2、内层为纳米Al2O3 的涂层的切削性能优于单层纳米TiO2 涂层的切削性能;当内层为纳米Al2O3、外层为纳米TiO2且Al2O3与TiO2的层厚比比较大时,纳米Al2O3/TiO2 多层涂层刀具的切削性能更好。

  • (4)在高速切削时,纳米多层涂层刀具比普通无涂层刀具更稳定,涂层表面的纳米颗粒能够将刀-屑接触界面间的滑动摩擦转化为滚动-滑动摩擦,有效降低了刀具黏结磨损,减少刀-屑粘黏现象和“烫伤”现象。

  • 参考文献

    • [1] HERNANDEZ M T,AGUILERA L D,PONCE A,et al.Tribological performance of TiN and TiCN coatings on a working tool steel[J].Journal of Mechanical Science and Technology,2018,32(8):3659-3666.

    • [2] MARINA V,ALEXEY V,NIKOLAY A,et al.Improvement of the performance properties of cutting tools using the multilayer composite wear-resistantcoatings based on nitrides of Cr,Mo,Zr,Nb,and Al[J].Materials Today:Proceedings,2021,38(4):1421-1427.

    • [3] 汪鹏,许昌庆,蔡飞,等.多弧离子镀TiAlSiN梯度涂层制备及切削性能[J].中国表面工程,2019,32(2):34-43.WANG Peng,XU Changqing,CAI Fei,et al.Preparation and machining properties of tialsin gradient coating by multi-arc ion plating[J].China Surface Engineering,2019,32(2):34-43.(in Chinese)

    • [4] SHARMA V,KUMAR M,SHUKLA V N.Tribobehaviour of nano-structured coatings deposited by various techniques:A review[J].Materials Today:Proceedings,2021,44(6):4097-4101.

    • [5] SKORDARIS G,BOUZAKIS K D,CHARALAMPOUS P,et al.Brittleness and fatigue effect of mono-and multilayer PVD films on the cutting performance of coated cemented carbide inserts[J].CIRP Annals,2014,63(1):93-96.

    • [6] 张云乾,丁彰雄,范毅.HVOF 喷涂纳米 WC-12Co 涂层的性能研究[J].中国表面工程,2005,18(6):25-29.ZHANG Yunqian,DING Zhangxiong,FAN Yi.Study on the performance of HVOF sprayed nano-WC-12Co coating[J].China Surface Engineering,2005,18(6):25-29.(in Chinese)

    • [7] RABINOVICH G S,YAMAMOTO K,KOVALEV A I,et al.Wear behavior of adaptive nano-multilayered TiAlCrN/NbN coatings under dry high performance machining conditions[J].Surface & Coatings Technology,2008,202(10):2015-2022.

    • [8] KOEHELER J S.Attempt to design a strong solid[J].Physical Review B,1970,2(2):547-551.

    • [9] 吴雁,王冰,肖礼军,等.Ti-Al-Si-N 多层梯度涂层的微观结构及力学性能研究[J].表面技术,2021,50(2):232-237.WU Yan,WANG Bin,XIAO Lijun,et al.Study on the microstructure and mechanical properties of Ti-Al-Si-N multilayer gradient coatings[J].Surface Technology,2021,50(2):232-237.(in Chinese)

    • [10] SOTOVA C,SITNIKOV N,BUBLIKOV J,et al.Influence of thickness of multilayer composite nano-structured coatings on tool life of metal-cutting tool[J].The European Physical Journal Conferences,2019,224(2):11-15.

    • [11] 孙磊,熊计,杨天恩.金属陶瓷及硬质合金表面 CVD/PVD 涂层的摩擦与切削性能[J].中国表面工程,2019,32(6):45-55.SUN Lei,XIONG Ji,YANG Tianen.Friction and cutting performance of CVD/PVD coating on cermet and cemented carbide surface[J].China Surface Engineering,2019,32(6):45-55.(in Chinese)

    • [12] PARSONS G N,GEORGE S M,KNEZ M.Progress and future directions for atomic layer deposition and ALD-based chemistry[J].Mrs Bulletin,2011,36(11):865-871.

    • [13] SONG G,TAN D Q.Atomic layer deposition for polypropylene film engineering—A review[J].Macromolecular Materials and Engineering,2020,305(6):68-92.

    • [14] HU Y,LU J,FENG H.Surface modification and functionalization of powder materials by atomic layer deposition:A review[J].RSC Advances,2021,11(20):11918-11942.

    • [15] SHAN C X,HOU X,Choy K L.Corrosion resistance of TiO2 films grown on stainless steel by atomic layer deposition[J].Surface & Coatings Technology,2008,202(11):2399-2402.

    • [16] WADULLAH H M,AJEEL S A,ABBASS M K.Synthesis and characterization of nanocoatings thin films by atomic layer deposition for medical applications[J].IOP Conference Series:Materials Science and Engineering,2019,518(3):2057-2064.

    • [17] FUSCO M,OLDHAM C,PARSONS G.Investigation of the corrosion behavior of atomic layer deposited Al2O3/TiO2 nanolaminate thin films on copper in 0.1 m NaCl[J].Materials,2019,12(4):672-696.

    • [18] 上海市金属切削技术协会.金属切削手册[M].2 版.上海:上海科学技术出版社,1982.Shanghai Metal Cutting Technology Association.Metal cutting manual[M].2ed.Shanghai:Shanghai Science and Technology Press,1982.(in Chinese)

    • [19] 瞿鑫.光学涂层对磁性金属的颜色和磁光效应的影响[D].北京:首都师范大学,2014.QU Xin.The influence of optical coating on the color and magneto-optical effect of magnetic metals[D].Beijing:Capital Normal University,2014.(in Chinese)

    • [20] ZHA X,CHEN F,JIANG F,et al.Correlation of the fatigue impact resistance of bilayer and nanolayered PVD coatings with their cutting performance in machining Ti6Al4V[J].Ceramics International,2019,45(12):14704-14717.

    • [21] DAROONPARVAR M,YAJID M A,YUSOF N M,et al.Fabrication and properties of triplex NiCrAlY/nano Al2O3-13%TiO2/nano TiO2 coatings on a magnesiumalloy by atmospheric plasma spraying method[J].Journal of Alloys and Compounds.2015,645(10):450-466.

    • [22] 李佩真,唐思文,孙林,等.基于原子沉积法的纳米 Al2O3 涂层微织构刀具刀-屑界面间摩擦因数研究[J].现代制造工程,2020,(10):26-32.LI Peizhen,TANG Siwen,SUN Lin,et al.Research on the friction coefficient between the tool-chip interface of nano-Al2O3 coating micro-textured tool based on atomic deposition method[J].Modern Manufacturing Engineering,2020,(10):26-32.(in Chinese)

    • [23] MUTHUKUMAR M,YADAV A,BOBJI M S.Wear characteristics of nanoporous alumina and copper fillednanocomposite coatings[J].Wear,2020,462(20):96-105.

    • [24] 庞俊忠,牛苜森,黄晓斌,等.高速铣削淬硬钢时的切屑形态试验研究[J].机械设计与制造,2021(1):152-155.PANG Junzhong,NIU Musen,HUANG Xiaobin,et al.Experimental study on chip morphology during high-speed milling of hardened steel[J].Machinery Design & Manufacture,2021(1):152-155.(in Chinese)

  • 参考文献

    • [1] HERNANDEZ M T,AGUILERA L D,PONCE A,et al.Tribological performance of TiN and TiCN coatings on a working tool steel[J].Journal of Mechanical Science and Technology,2018,32(8):3659-3666.

    • [2] MARINA V,ALEXEY V,NIKOLAY A,et al.Improvement of the performance properties of cutting tools using the multilayer composite wear-resistantcoatings based on nitrides of Cr,Mo,Zr,Nb,and Al[J].Materials Today:Proceedings,2021,38(4):1421-1427.

    • [3] 汪鹏,许昌庆,蔡飞,等.多弧离子镀TiAlSiN梯度涂层制备及切削性能[J].中国表面工程,2019,32(2):34-43.WANG Peng,XU Changqing,CAI Fei,et al.Preparation and machining properties of tialsin gradient coating by multi-arc ion plating[J].China Surface Engineering,2019,32(2):34-43.(in Chinese)

    • [4] SHARMA V,KUMAR M,SHUKLA V N.Tribobehaviour of nano-structured coatings deposited by various techniques:A review[J].Materials Today:Proceedings,2021,44(6):4097-4101.

    • [5] SKORDARIS G,BOUZAKIS K D,CHARALAMPOUS P,et al.Brittleness and fatigue effect of mono-and multilayer PVD films on the cutting performance of coated cemented carbide inserts[J].CIRP Annals,2014,63(1):93-96.

    • [6] 张云乾,丁彰雄,范毅.HVOF 喷涂纳米 WC-12Co 涂层的性能研究[J].中国表面工程,2005,18(6):25-29.ZHANG Yunqian,DING Zhangxiong,FAN Yi.Study on the performance of HVOF sprayed nano-WC-12Co coating[J].China Surface Engineering,2005,18(6):25-29.(in Chinese)

    • [7] RABINOVICH G S,YAMAMOTO K,KOVALEV A I,et al.Wear behavior of adaptive nano-multilayered TiAlCrN/NbN coatings under dry high performance machining conditions[J].Surface & Coatings Technology,2008,202(10):2015-2022.

    • [8] KOEHELER J S.Attempt to design a strong solid[J].Physical Review B,1970,2(2):547-551.

    • [9] 吴雁,王冰,肖礼军,等.Ti-Al-Si-N 多层梯度涂层的微观结构及力学性能研究[J].表面技术,2021,50(2):232-237.WU Yan,WANG Bin,XIAO Lijun,et al.Study on the microstructure and mechanical properties of Ti-Al-Si-N multilayer gradient coatings[J].Surface Technology,2021,50(2):232-237.(in Chinese)

    • [10] SOTOVA C,SITNIKOV N,BUBLIKOV J,et al.Influence of thickness of multilayer composite nano-structured coatings on tool life of metal-cutting tool[J].The European Physical Journal Conferences,2019,224(2):11-15.

    • [11] 孙磊,熊计,杨天恩.金属陶瓷及硬质合金表面 CVD/PVD 涂层的摩擦与切削性能[J].中国表面工程,2019,32(6):45-55.SUN Lei,XIONG Ji,YANG Tianen.Friction and cutting performance of CVD/PVD coating on cermet and cemented carbide surface[J].China Surface Engineering,2019,32(6):45-55.(in Chinese)

    • [12] PARSONS G N,GEORGE S M,KNEZ M.Progress and future directions for atomic layer deposition and ALD-based chemistry[J].Mrs Bulletin,2011,36(11):865-871.

    • [13] SONG G,TAN D Q.Atomic layer deposition for polypropylene film engineering—A review[J].Macromolecular Materials and Engineering,2020,305(6):68-92.

    • [14] HU Y,LU J,FENG H.Surface modification and functionalization of powder materials by atomic layer deposition:A review[J].RSC Advances,2021,11(20):11918-11942.

    • [15] SHAN C X,HOU X,Choy K L.Corrosion resistance of TiO2 films grown on stainless steel by atomic layer deposition[J].Surface & Coatings Technology,2008,202(11):2399-2402.

    • [16] WADULLAH H M,AJEEL S A,ABBASS M K.Synthesis and characterization of nanocoatings thin films by atomic layer deposition for medical applications[J].IOP Conference Series:Materials Science and Engineering,2019,518(3):2057-2064.

    • [17] FUSCO M,OLDHAM C,PARSONS G.Investigation of the corrosion behavior of atomic layer deposited Al2O3/TiO2 nanolaminate thin films on copper in 0.1 m NaCl[J].Materials,2019,12(4):672-696.

    • [18] 上海市金属切削技术协会.金属切削手册[M].2 版.上海:上海科学技术出版社,1982.Shanghai Metal Cutting Technology Association.Metal cutting manual[M].2ed.Shanghai:Shanghai Science and Technology Press,1982.(in Chinese)

    • [19] 瞿鑫.光学涂层对磁性金属的颜色和磁光效应的影响[D].北京:首都师范大学,2014.QU Xin.The influence of optical coating on the color and magneto-optical effect of magnetic metals[D].Beijing:Capital Normal University,2014.(in Chinese)

    • [20] ZHA X,CHEN F,JIANG F,et al.Correlation of the fatigue impact resistance of bilayer and nanolayered PVD coatings with their cutting performance in machining Ti6Al4V[J].Ceramics International,2019,45(12):14704-14717.

    • [21] DAROONPARVAR M,YAJID M A,YUSOF N M,et al.Fabrication and properties of triplex NiCrAlY/nano Al2O3-13%TiO2/nano TiO2 coatings on a magnesiumalloy by atmospheric plasma spraying method[J].Journal of Alloys and Compounds.2015,645(10):450-466.

    • [22] 李佩真,唐思文,孙林,等.基于原子沉积法的纳米 Al2O3 涂层微织构刀具刀-屑界面间摩擦因数研究[J].现代制造工程,2020,(10):26-32.LI Peizhen,TANG Siwen,SUN Lin,et al.Research on the friction coefficient between the tool-chip interface of nano-Al2O3 coating micro-textured tool based on atomic deposition method[J].Modern Manufacturing Engineering,2020,(10):26-32.(in Chinese)

    • [23] MUTHUKUMAR M,YADAV A,BOBJI M S.Wear characteristics of nanoporous alumina and copper fillednanocomposite coatings[J].Wear,2020,462(20):96-105.

    • [24] 庞俊忠,牛苜森,黄晓斌,等.高速铣削淬硬钢时的切屑形态试验研究[J].机械设计与制造,2021(1):152-155.PANG Junzhong,NIU Musen,HUANG Xiaobin,et al.Experimental study on chip morphology during high-speed milling of hardened steel[J].Machinery Design & Manufacture,2021(1):152-155.(in Chinese)

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