N_2流量对刀具硬质合金表面磁控溅射TiAlSiN涂层组织和摩擦性的影响

运用脉冲直流磁控溅射的方法在刀具硬质合金表面制备TiAlSiN复合涂层,实验测试N_2流量对刀具硬质合金表面磁控溅射TiAlSiN涂层组织和摩擦性的影响。研究结果表明:TiAlSiN涂层出现TiSiN和AlN衍射峰。当N_2浓度很高时,可以对晶粒生长起到阻碍作用,从而获得更加致密的组织结构。当设定较小N_2流量时,涂层获得了最高硬度;当N_2流量到达100 mL/min时,硬度提高到25.2 GPa,弹性模量保持稳定。随着N_2流量的增加,涂层残余应力表现出增加,涂层结合力表现为先增大后减小。随着N_2流量的增加,涂层摩擦系数表现出增加,磨损率表现出减小。在N_2流量100 mL/min条件下,摩擦系数到达最大值0.55,磨损率到达最小值2.12。设定较低的N_2流量,生成许多磨屑,形成犁沟;设定更高的N_2流量,表现出更好的耐摩擦磨损性能。     

活塞环表面CrN基复合膜的组织结构与摩擦副匹配机理研究

为降低活塞环与缸套摩擦副的磨损及延长活塞环的使用寿命,本文采用多弧离子镀在活塞环表面制备了CrN及CrTiAlN复合膜,比较研究了Cr电镀层与CrN,CrTiAlN复合膜的纳米硬度及高温摩擦磨损性能,采用X射线衍射、扫描电子显微镜、能谱仪、纳米硬度仪和发动机台架试验装置,系统分析了CrTiAlN复合膜的成分、相结构、表面形貌、纳米硬度和抗高温摩擦磨损性能,研究结果表明:CrTiAlN复合膜的主要组成成分为Cr,Ti,Al,N,复合膜中含有CrN,Cr2N,TiN和非晶的AlN相。CrTiAlN复合膜表面组织致密,均匀分布着许多颗粒,最大的达400 nm以上,而最小的仅几十纳米。断面结构为纤维状的柱状晶组织。CrN,CrTiAlN复合膜比电镀Cr具有较优的力学性能和高温摩擦磨损性能,与缸套匹配性能良好,最后对三种活塞环涂层的摩擦副匹配机理进行了分析讨论。     

N_2∶O_2流量比对多弧离子镀Cr-O-N复合涂层结构及性能的影响

目前,关于N_2∶O_2流量比如何影响Cr-O-N涂层结构和性能的报道较少。采用多弧离子镀技术在硅片(100)和硬质合金基底上沉积了一系列不同N_2∶O_2流量比的Cr-O-N复合涂层;采用X射线衍射仪分析涂层晶体结构;采用共聚焦显微拉曼光谱仪分析薄膜氧化物相结构;采用扫描电镜观察涂层形貌,并通过能谱仪分析其成分;利用原子力显微镜观察涂层表面三维形貌;采用显微硬度仪测量涂层硬度;通过球-盘摩擦磨损仪测量涂层摩擦磨损性能,系统地研究了O_2流量占比对复合涂层结构和性能的影响。结果表明:Cr-O-N复合涂层由CrN和Cr_2O_3复合相组成;随着沉积过程中O_2流量占比的增加,涂层中N和Cr的含量呈下降趋势,而Cr_2O_3含量逐渐增加;随着O_2流量占比的增加,涂层表面形貌发生变化,涂层表面粗糙度在氧气占比为0.34时达到最大值85.86 nm,此时涂层具有最低的摩擦系数0.48;Cr-O-N涂层的硬度高于CrN和Cr_2O_3涂层,摩擦系数比CrN涂层高,但低于Cr_2O_3涂层。     

氮化物硬质涂层中Cr、Ti和Al元素对摩擦磨损特性的影响

利用四靶闭合场非平衡磁控溅射(CFUBMS)技术在石英玻璃和抛光不锈钢片两种基底上制备含有Cr、Ti和Al元素组合的各种氮化物涂层.采用摩擦磨损仪测试涂层摩擦系数,应用金相显微镜对各个涂层磨痕形态进行分析,结果表明TiN、CrN、TiAlN、CrAlN以及CrTiAlN涂层的摩擦系数依次减小,耐磨特性依次提高;结合涂层的X射线光电子能谱分析,可以得到含有Al元素涂层中形成了AlN的结构,提高涂层的硬度,增加耐磨特性;在涂层中含有Cr元素形成了氧化物Cr2O3可以提高涂层自排屑能力,减小摩擦系数,增加耐磨特性,含Ti元素形成的氧化物TiO2则不利于涂层的摩擦磨损特性;由于CrTiAlN本身具有比三元氮化物更高的涂层硬度,且含有Al和Cr元素,因此该涂层具有最好的摩擦磨损性能.     

N_2流量对HIPIMS/DCMS共沉积制备TiAlCrN涂层结构及性能的影响

利用高功率磁控溅射与直流反应磁控溅射共沉积技术制备了不同N_2流量下的TiAlCrN复合硬质涂层。采用X射线衍射仪(XRD)、薄膜综合性能测试仪以及大气球盘摩擦磨损试验机分析测试了涂层的微观组织结构、力学性能及摩擦学性能。结果显示:随N_2流量的提高,涂层沉积速率先上升后下降;XRD测试表明增加N_2流量可有效抑制h-Al N相的生成,并且改善了涂层的结晶性能;同时,表面粗糙度先下降后升高,最小值可达45.7 nm;涂层硬度逐渐上升,而弹性模量在取得最大值后呈下降趋势,最大值分别为31.2和423.8 GPa;划痕临界载荷在N_2流量为250 m L/min时获得最优值5.5 N。摩擦学性能方面,随N_2流量的提高,涂层磨损率先下降后上升,最小值为2.6×10~(-17)m~3/N·m。由此可见,在一定范围内调节N_2流量可显著改善涂层的强度及耐磨损性能。     

CrTiAlN薄膜的微观结构及其高温摩擦磨损性能

采用闭合场非平衡磁控溅射离子镀技术,在M2高速钢表面制备CrTiAlN多层薄膜。利用XRD、SEM、EDS和球-盘式摩擦磨损试验机研究薄膜微观结构和高温摩擦磨损性能。结果表明:CrTiAlN薄膜均匀致密,呈FCC结构。高温摩擦磨损试验表明:从室温到600℃,随着温度升高,薄膜摩擦系数先增大后减小,磨损量和磨损率随着温度升高而增加,CrTiAlN薄膜在600℃环境下的磨损形式主要是氧化磨损和磨粒磨损。     

N2流量对刀具硬质合金表面磁控溅射TiAlSiN涂层组织和摩擦性的影响北大核心CSCD

运用脉冲直流磁控溅射的方法在刀具硬质合金表面制备TiAlSiN复合涂层,实验测试N2流量对刀具硬质合金表面磁控溅射TiAlSiN涂层组织和摩擦性的影响。研究结果表明:TiAlSiN涂层出现TiSiN和AlN衍射峰。当N2浓度很高时,可以对晶粒生长起到阻碍作用,从而获得更加致密的组织结构。当设定较小N2流量时,涂层获得了最高硬度;当N2流量到达100 mL/min时,硬度提高到25.2 GPa,弹性模量保持稳定。随着N2流量的增加,涂层残余应力表现出增加,涂层结合力表现为先增大后减小。随着N2流量的增加,涂层摩擦系数表现出增加,磨损率表现出减小。在N2流量100 mL/min条件下,摩擦系数到达最大值0.55,磨损率到达最小值2.12。设定较低的N2流量,生成许多磨屑,形成犁沟;设定更高的N2流量,表现出更好的耐摩擦磨损性能。     

CrTiAlN涂层的高温抗氧化性能

为提高M2高速钢的高温抗氧化能力,采用闭合场非平衡磁控溅射离子镀技术,在M2高速钢基体上制备了CrTiAlN涂层。在500℃、700℃、900℃这三个温度下对试样进行氧化实验。利用SEM观察CrTiAlN涂层氧化前后表面及断面形貌,采用GIXRD和EDS分析涂层的物相组成。结果表明,CrTiAlN涂层在900℃时仍然具有良好的抗氧化性能。     

不同掺Ag含量下高温(800℃)沉积CrN/Ag涂层的组织结构及其性能

为研究高温下掺入Ag的CrN涂层的组织性能,在沉积温度为800℃的条件下采用直流反应磁控溅射技术制备CrN/Ag硬质涂层。采用扫描电镜(SEM)、EDS能谱仪、X射线衍射(XRD)和维氏硬度计,综合分析了800℃沉积温度下,对不同Ag掺杂情况下CrN/Ag涂层的组织结构和性能特点,以及700℃热处理工艺对其的影响。结果表明,Ag添加导致CrN晶相生长由(200)择优取向向无择优取向转变,并使得CrN/Ag涂层表面粗糙化;少量Ag(7%(原子分数))添加可提高涂层硬度,过多Ag(21%(原子分数))添加明显降低涂层硬度;高温热处理(700℃/1h)后,纯CrN涂层的氧化并不明显,但是,随Ag含量增加,涂层氧化程度逐渐增加,且在高Ag(21%(原子分数))涂层中Ag溢出现象显著;涂层氧化及Ag溢出导致涂层硬度显著降低。     

微弧氧化/磁控溅射复合涂层对镁微观结构与摩擦性能的影响

镁基材料表面进行微弧氧化处理(MAO)制备的多孔结构的陶瓷涂层在干摩擦环境下的摩擦系数较高,本文采用微弧氧化结合非平衡磁控溅射技术在纯镁基体表面制备出了MAO/CrN复合涂层。通过扫描电镜、显微硬度测试、X射线衍射仪能谱、摩擦磨损实验等手段研究了复合涂层的形貌、成分及摩擦磨损性能。结果表明:MAO/CrN复合涂层相比单层的MAO涂层力学与摩擦性能得到显著提高,其中硬度升高48%,载荷为1 N时的平均摩擦系数降低32.3%,转速为700 r/min时,磨损率降低达到74%。CrN/MAO复合涂层与WC硬质合金球在干摩擦过程中,在表层CrN涂层被磨穿之前,复合涂层磨损形式以黏着磨损和疲劳磨损为主。在表层CrN涂层被磨穿MAO涂层未被磨穿前,复合涂层的磨损形式以三体磨粒磨损为主。     

A study on the abrasive and erosive wear behavior of arc-deposited Cr-N-O coatings on tool steel

In this study, the cathodic arc evaporation technique, by using the chromium target and controlling the flow rate of nitrogen/oxygen reactive gases, was utilized to deposit three different Cr-N-O coatings (CrN, CrN/Cr(N,O), CrN/Cr₂O₃) on AISI M2 tool steel. Two types of wear tests were applied to evaluate the abrasive and erosive wear behavior of the coated and uncoated specimens. One was the ball-on-disk abrasion test to measure the friction coefficient of these specimens. The other was the erosion test using Al₂O₃ particles (~ 177 µm in size and Mohr 7 scale) of about 5 g, and then the surface morphologies of the eroded specimens were observed. To further understand the coating effects on the two wear behaviors of M2 steel, coating structure, morphology, and adhesion were analyzed using XRD, SEM, and TEM, respectively. The results showed that surface roughness and adhesion of the double-layered coatings (CrN/Cr(N,O) and CrN/Cr₂O₃) were inferior to those of monolithic CrN, but their hardness and elastic modulus were superior to those of CrN. In the abrasive behavior, Cr-N-O coatings reduced the friction coefficient of M2 substrate. In particular, the CrN/Cr₂O₃ has the highest hardness/elastic (H/E) modulus ration, therefore the lowest friction coefficient, among all the coated-specimens tested. In the erosive behavior, the coated specimens exhibited better erosion resistance as compared to the uncoated ones, at the impingement angles of either 30^o or 90^o. Moreover, the erosion resistance of CrN/Cr(N,O) coatings was superior to that of CrN/Cr₂O₃ coatings due to its better adhesion.     

氧气流量对超音速火焰喷涂多尺度WC-17Co涂层组织结构与性能的影响

工艺参数对超音速火焰喷涂WC-Co涂层的组织结构、硬度、耐磨性影响较大,但相关研究较少。采用超音速火焰喷涂技术(HVOF)在4种氧气流量(322,402,482,543 L/min)下将多尺度WC-17Co粉末(含30%纳米WC和70%微米WC)喷涂在Q235钢基体表面制备WC-17Co涂层。采用扫描电镜(SEM)和X射线衍射仪(XRD)分析涂层的截面形貌和物相,测试了涂层的硬度值,通过销盘磨损试验机测试涂层的耐磨损性能,研究氧气流量对多尺度WC-17Co涂层组织结构与耐磨性能的影响。结果发现:4种氧气流量下所制备的涂层组织致密,孔隙率为0.306%~1.290%;随着氧气流量降低,涂层中WC分解更严重,当氧气流量为322 L/min时,涂层中分解相(W_2C、W和Co_3W_3C)最多;涂层的硬度随着氧气流量增加而增加,当氧气流量为543 L/min时,涂层的硬度[(933.8±29.3)HV_(3N)]是Q235钢[(183±7)HV_(3N)]的5倍;随着氧气流量增加,涂层磨损失重逐渐减小,当氧气流量为543 L/min时,涂层的磨损失重仅为(8.57±0.95)mg,耐磨损性能较基材明显提高。     

Microstructure and wear behaviour of silicon doped Cr–N nanocomposite coatings

Hard Cr–N and silicon doped Cr–Si–N nanocomposite coatings were deposited using closed unbalanced magnetron sputtering ion plating system. Coatings doped with various Si contents were synthesized by changing the power applied on Si targets. Composition of the films was analyzed using glow discharge optical emission spectrometry (GDOES). Microstructure and properties of the coatings were characterized using X-ray diffraction (XRD), transmission electron microscopy (TEM), and nano-indentation. The harnesses and the elastic modulus of Cr–Si–N coatings gradually increased with rising of silicon content and exhibited a maximum at silicon content of 4.1 at.% and 5.5 at.%. The maximum hardness and elastic modulus of the Cr–Si–N nanocomposite coatings were approximately 30 GPa and 352 GPa, respectively. Further increase in the silicon content resulted in a decrease in the hardness and the elastic modulus of the coatings. Results from XRD analyses of CrN coatings indicated that strongly preferred orientations of (111) were detected. The diffraction patterns of Cr–Si–N coatings showed a clear (220) with weak (200) and (311) preferred orientations, but the peak of CrN (111) was decreased with the increase of Si concentration. The XRD data of single-phase Si₃N₄ was free of peak. The peaks of CrN (111) and (220) were shifted slightly and broadened with the increase of silicon content. SEM observations of the sections of Cr–Si–N coatings with different silicon concentrations showed a typical columnar structure. It was evident from TEM observation that nanocomposite Cr–Si–N coatings exhibited nano-scale grain size. Friction coefficient and specific wear rate (SWR) of silicon doped Cr–N coatings from pin-on-disk test were significantly lower in comparison to that of CrN coatings.     

Bias effects on microstructure, mechanical properties and corrosion resistance of arc-evaporated CrTiAlN nanocomposite films on AISI 304 stainless steel

CrTiAlN films were deposited on AISI 304 stainless steel by cathodic arc evaporation under a systematic variation of the substrate bias voltage. The effects of substrate bias on the coating morphology and mechanical properties, such as structure, composition, adhesion, hardness and Young's modulus, were studied in details using field emission scanning electron microscopy, X-ray diffraction, electron probe microanalysis and indenter. Polarization test and immersion test were also carried out to evaluate the corrosion behavior of the various films. CrTiAlN films are nanocrystalline that exhibit a CrN/TiAlN multi-layered morphology. At the optimal value of substrate bias voltage (i.e., − 150 V), the CrTiAlN film showed an increased Cr content and improved properties, such as higher adhesion, higher hardness (38 ± 2 GPa), and greater Young's modulus (319 ± 16 GPa) vs. the films deposited at other substrate bias voltages. Moreover, the optimum film has better corrosion resistance in 3.5 wt.% NaCl and 20 vol.% HCl solutions.     

脉冲电流密度对Ni-WC/Co纳米复合镀层摩擦磨损性能的影响

目前,通过脉冲电沉积制备Ni-WC/Co复合镀层的研究报道较少。为了探究Ni-WC/Co纳米复合镀层对材料表面摩擦性能的影响,采用脉冲电沉积制备Ni-WC/Co纳米复合镀层,研究脉冲峰值电流密度对复合镀层晶体结构、晶粒尺寸和硬度的影响;室温下,在MM-W1B立式万能摩擦磨损试验机上测试复合镀层的摩擦磨损性能,分析其磨损机理。结果表明:随着峰值电流密度的增加,复合镀层晶粒尺寸先减小后增大,硬度则是先增大后减小,复合镀层的摩擦系数和磨损量都是先降低后升高;当峰值电流密度为10 A/dm2时,复合镀层的平均晶粒尺寸最小,硬度最高,摩擦系数和磨损量最低,耐磨性能最佳,复合镀层表面主要呈现轻微的划痕,且磨痕较窄,无疲劳磨损。     

Bias effects on the tribological behavior of cathodic arc evaporated CrTiAlN coatings on AISI 304 stainless steel

In this study, CrTiAlN coatings were deposited on AISI 304 stainless steel by cathodic arc evaporation under a systematic variation of the substrate bias voltage. The coating morphology and properties including surface roughness, adhesion, hardness/elastic modulus (H/E) ratio, and friction behavior were analyzed to evaluate the impact of the substrate bias voltage on the coating microstructure and properties. The results suggest that for an optimized value of the substrate bias voltage, i.e. − 150 V, the CrTiAlN coatings showed increased Cr content and improved properties, such as higher adhesion strength, hardness, and elastic modulus in comparison to the coatings deposited by other substrate bias voltage. Moreover, the optimum coatings achieved a remarkable reduction in the steel friction coefficient from 0.65 to 0.45.     

纳米颗粒大小对Ni-P合金镀层性能的影响及镀层制备工艺参数优化

为了提高农业刀具的使用寿命,在65Mn钢试件基体表面上,采用电沉积技术制备Ni-P-BN(h)纳米复合镀层,研究不同直径大小的BN(h)颗粒对镀层显微组织、硬度及摩擦磨损性能的影响;并通过正交试验,确定制备复合镀层的最优工艺参数。结果表明:随着BN(h)颗粒直径的增大,复合镀层有晶化的趋势;镀液中加入直径100 nm的BN(h)颗粒所制备的镀层表面胞体均匀致密、硬度最大、耐磨损性能最好;镀层形成过程中,纳米颗粒相互碰撞几率增大,导致晶核分布不均,影响表面质量并且减小耐磨损性能;制备Ni-P-BN(h)纳米复合镀层最优工艺参数为电流密度4.308 A/dm~2,BN(h)浓度15.00 g/L,施镀温度60℃,施镀时间3 h,所得硬度和磨损量分别为621.664 HV_(2N),2.665 8×10~(-3)mm~3,相较于65Mn基体硬度提升了1.2倍,磨损量降低86.5%。     

Production and characterization of duplex coatings (HVOF and PVD) on Ti-6Al-4V substrate

Present paper deals with modelling, production and characterization of HVOF PVD (WC-Co and TiN or CrN, respectively) duplex coatings deposited on Ti-6Al-4V substrate for application in automotive industry. As a preliminary analysis, an analytical study of the contact stress distribution under spherical indenter in both coated and uncoated systems, and a finite element evaluation of residual stresses were performed: results showed that the presence of an interlayer with intermediate hardness and stiffness (such as the WC-Co coating) plays a fundamental role in the improvement of the load carrying capacity. Starting from the results of simulations, morphological and compositional characterization of the coatings were performed using SEM and AFM techniques. Mechanical properties were investigated by micro indentation techniques and composite hardness modelling; toughness of the system was qualitatively analysed by Rockwell C indentation. Wear rate of the coatings was measured by an implemented rotating wheel method. Results show higher superficial composite hardness, toughness, adhesion and lower wear rate, in comparison with the simple monolayer system.