具有纳米调制结构的AlTiN/AlCrN复合涂层在干摩擦条件下的摩擦磨损性能研究

目的 研究干摩擦条件下不同AlTiN/AlCrN多层膜纳米调制结构对摩擦磨损行为的影响。方法 将处理过的合金工具钢和单晶硅片作为膜层生长的基底材料,在膜层制备之前,先对基底材料进行预处理,然后使用多靶磁控溅射纳米膜层系统沉积一系列不同调制周期和调制比的AlTiN/AlCrN纳米多层膜。通过控制涂层总厚度不变,在调制比为1︰1时,设计不同的调制周期,择优选出磨损量最小、耐磨性最好的调制周期,并以此为恒定值,进而设计不同调制比的试样。采用X射线衍射仪(XRD)、摩擦磨损试验机分析与表征纳米多层膜的微观结构和性能,研究调制周期和调制比对AlTiN/AlCrN纳米多层膜微观结构和干摩擦条件下摩擦磨损性能的影响。结果 AlTiN/AlCrN纳米多层膜主体均为面心立方结构,且在(111)、(200)和(220)晶面择优取向。调制结构对多层膜的磨损特性影响较大,当调制周期为14.4 nm时,在干摩擦条件下AlTiN/AlCrN纳米多层膜的摩擦磨损量最小;在调制周期恒定为14.4 nm情况下,当调制比为3︰1时,在干摩擦条件下AlTiN/AlCrN纳米多层膜的耐磨性能最好;AlTiN/AlCrN纳米多层膜的磨损机理主要以磨粒磨损和黏附磨损为主。结论 优化的AlTiN/AlCrN多层膜纳米调制结构技术可应用在切削刀具的表面再制造领域,从而延长刀具工作寿命,通过涂层良好的耐磨性能提升设备的加工效率。     

电沉积Zn-Ni合金纳米多层膜的耐蚀性能

为了研究Zn-Ni合金纳米多层膜的耐蚀性能,制备了纯锌、锌镍合金及镍含量不同的锌镍合金纳米多层膜3种镀层.采用中性盐雾试验、浸泡试验和电化学试验法对锌镍合金多层膜的耐蚀性进行了研究.采用EDAX、锌镍合金相图、扫描电镜,对多层膜的成分、相结构和镀层的表面形貌进行了研究.结果表明:合金多层膜是由含镍量为14%左右的低镍层和含镍量为77%左右的高镍层叠加而成,其低镍层的相结构主要为γ相,高镍层的相结构为γ+α2种相组织的混合相;多层膜表面较为致密,无明显的缺陷组织,其调制波长为366 nm左右,其耐蚀性能优于纯锌镀层和锌镍合金镀层.     

TiN/Ti多层膜调制比对摩擦磨损行为影响的研究

考察了TiN/Ti多层膜调制比对其摩擦磨损行为的影响. 采用磁过滤阴极弧沉积的方法制备了具有不同调制比的TiN/Ti多层膜, 用扫描电镜和透射电镜对其层状结构及子层结构进行了观察和分析. 用纳米压痕和SRV摩擦磨损试验的方法, 对多层膜进行了纳米硬度和弹性模量测试以及摩擦磨损实验. 结果表明, 所制备的TiN/Ti多层膜层状结构清晰, 与基底结合良好, 调制比对多层膜的硬度和磨损特性影响较大, 而对摩擦系数的影响却不明显. 结合实验结果, 讨论了硬度与弹性模量的比值(H/E值)对TiN/Ti多层膜耐磨性的影响.     

40Cr钢表面涂敷层的磨损和腐蚀磨损研究

用掺有 10 %(w)CeO2 粉末的及未掺的KF 2 0 1铁基高强度耐磨合金粉末 ,对淬火态 40Cr钢材表面进行喷涂、喷熔和激光涂敷等表面处理 ,考察了用这 3种工艺制作的 6种涂层的显微组织、硬度分布、无润滑磨损和腐蚀磨损。结果表明 ,涂层的磨损抗力和腐蚀磨损抗力都比 40Cr钢基底的大为提高。激光涂敷层的磨损抗力达到淬火态 40Cr钢基底的 5倍以上 ,在 5 %盐水 +石英砂内进行腐蚀磨损试验 ,激光涂敷层的腐蚀磨损抗力达到 40Cr钢基底的 2倍以上。在KF 2 0 1粉末中掺入CeO2 ,Ce能使涂层组织细化 ,涂层磨损抗力与腐蚀磨损抗力得到进一步的提高。     

不同调制周期的TiSiN/TaVN纳米多层膜的结构及性能

为了探究调制周期对TiSiN/TaVN纳米多层膜性能的影响,使用磁控溅射仪在304不锈钢和硅片上沉积TiSiN/TaVN纳米多层膜,采用X射线衍射仪、扫描电镜、纳米压痕仪、划痕仪、表面性能综合测试仪等分析和探索不同调制周期的TiSiN/TaVN纳米多层膜的微观结构、力学性能和摩擦学性能。结果表明：TiSiN/TaVN纳米多层膜均为面心立方结构,在(111)晶面和(200)晶面呈现择优取向。随着调制周期的增大,TiSiN/TaVN纳米多层膜的硬度、弹性模量、膜基结合力等先增大后减小,摩擦系数先减小后增大。当调制周期为8 nm时,TiSiN/TaVN纳米多层膜具有优异的力学性能和摩擦学性能,硬度最高为28.79 GPa,弹性模量最大为301 GPa,膜基结合力最高为29.2 N。薄膜硬度强化的主要原因是固溶强化和交变应力场。当调制周期为8 nm时,TiSiN/TaVN纳米多层膜的摩擦系数最小值为0.14,磨损机理主要为磨粒磨损和氧化磨损。TiSiN/TaVN纳米多层膜摩擦学性能改善的主要原因之一是摩擦过程中V元素与氧气反应形成了具有自润滑性能的Magnéli相氧化物V₂     

35CrMo钢硫氮共渗层的摩擦学性能

目前,低温离子渗硫技术在石油钻杆丝扣上的应用还没有先例.应用离子渗氮与离子渗硫技术,在35CrMo钢表面制备了硫氮共渗复合层.采用自制的球-盘磨损试验机,在含铜润滑脂润滑条件下,对比研究了离子渗氮层与硫氮共渗层的摩擦磨损性能;采用白光干涉仪和扫描电子显微镜观察了表面改性层和磨损表面的形貌,利用纳米压痕仪测量了渗层的硬度和弹性模量,用X射线光电子能谱研究了磨损表面边界润滑膜的元素成分及其含量随深度的变化.结果表明,35CrMo钢经硫氮共渗处理后,表面比较粗糙,硬度较低,符合理想的摩擦表面要求;硫氮共渗层有了渗氮层的支撑,其减摩耐磨性能在低速低载下优于渗氮层,满足钻杆接头的使用性能要求.     

失配位错对Cu/Ni多层膜力学性能的影响

通过对Cu／Ni多层膜纳米压痕过程的二维分子动力学模拟,研究了失配位错对多层膜力学性能的影响。结果表明,失配位错网对滑移位错的阻碍作用使Cu／Ni多层膜得以强化,并且这种强化作用依赖于多层膜的调制波长(相邻两膜层的厚度之和)。当调制波长大于临界值λc时,失配位错的应力场随膜层厚度变化不大;当调制波长小于临界值λc时,失配位错的运动导致了界面处的应力集中,从而使多层膜的力学性能下降。为了优化多层膜的力学性能,临界调制波长要大于在单膜层内产生位错的深度。     

Ti-Si-N纳米多层膜的研究进展

TiN存在高温氧化不良、固有脆性等缺点。将硅混合到TiN网络中,形成Ti-Si-N纳米多层膜,此纳米多层膜的硬度有了显著的提高。Ti-Si-N纳米多层膜是一类有着广阔应用前景的新材料,它在涂料、航空航天工业、电子器件等众多领域都有着广泛的应用。尤其在硬质合金刀具领域,较高的硬度、较好的耐磨性和韧性能够延长刀具的使用寿命。Ti-Si-N纳米多层膜制备方法有物理气相沉积和化学气相沉积两大类。物理气相沉积法是原材料在腔体的一端蒸发,然后沉积在腔体另一端较冷的基体上的方法。化学气相沉积在高温下发生化学反应,使钛、硅、氮原子发生重新组合,在基体表面生成Ti-Si-N纳米多层膜。与物理气相沉积方法相比,化学气相沉积方法需要的温度更高,并且化学反应中存在SiH 4等危险性气体,不适合大规模工业生产。Ti-Si-N纳米多层膜的性能主要受Si含量、调制周期和热处理温度等影响。随着Si含量的增加,纳米多层膜的性能先增强后减弱,Si含量在2.76%(质量分数)时,纳米多层膜硬度最大,摩擦系数最小。不同调制周期的多层膜性能优于单层膜,调制周期为0.7 nm时,纳米多层膜硬度达到28.7 GPa,弹性模量为301.1 GPa。随着退火温度的升高,纳米多层膜的附着性先增强后减弱,温度在800～950℃时,纳米多层膜硬度达到(49.7±0.83) GPa,结合力为83 N。纳米多层膜有超硬性,耐磨性和耐高温氧化性。对于纳米多层膜的超硬性,不同学者提出了不同的强化理论:交变应力场、模量差和Hall-petch强化理论;通过摩擦磨损实验可以判断纳米多层膜的磨损机制;在TiN中加入Si,生成的Ti-Si-N纳米多层膜具有耐高温氧化性。     

磁控溅射SiC／W纳米多层膜的微结构研究

用磁控溅射法在Ｓｉ基底上制备了不同调制波长的ＳｉＣ／Ｗ纳米多层膜。利用小角度Ｘ射线衍射技术，详细研究了其中典型的多层膜的调制周期性。各子层的厚度及界面平整度等界面微观结构。结果表明：磁控溅射法制备的纳米多层膜具有较好的周期结构及陡峭的界面梯度，由衍射峰位置计算出的界面不均匀旗与子层厚度之比一般在５％以内。     

TiAlN/TiN纳米多层膜的微结构与力学性能

采用多靶反应磁控溅射制备了一系列TiAlN层厚固定,TiN层厚在一定范围内连续变化的不同调制结构的TiAlN/TiN纳米多层膜,并使用X射线衍射分析、扫描电子显微镜、纳米压痕仪和CETR-UMT-3型多功能摩擦磨损试验机对多层膜的微观结构和力学性能进行了表征和分析。研究结果表明:TiAlN/TiN纳米多层膜形成了周期性良好的成分调制结构,其中TiN层的插入并没有打断TiAlN层的柱状晶生长。在一定的调制周期下,TiN层和TiAlN层能够形成共格外延生长结构,多层膜呈现硬度异常升高的超硬效应,当TiN层厚约为1.6 nm时多层膜的硬度达到最大值50 GPa,并具有相比于TiAlN单层膜更低的摩擦系数。进一步增加TiN层厚,由于多层膜共格界面结构的破坏,多层膜的硬度随之降低。     

Microstructure and Micromechanical Properties of SiC-W Multilayer Films

SiC-W multilayer thin films with various modulation wavelengths were prepared by a magnetron sputtering system. Using low-angle x-ray diffraction (LXD), their interface microstructure and the modulation period were studied. The mechanical properties of these films were investigated using an ultramicrohardness (UMH) tester with loads smaller than 20 mN. It was shown that the UMH values of multilayer films varies with applied load L and modulation wavelength. When L was 5 mN, was 10 nm, the UMH reached a maximum, 19.869 GPa, which was 1.02 times higher than that of the homogeneously mixed film. The anomalous peak effect of UMH varying with the modulation wavelength is discussed.     

喷射电沉积纳米Ni/Co多层镀层及其组织性能

目前,纳米金属多层膜的研究体系和应用范围有待扩展,镀层成形机理、强化机理等方面有待深入研究。利用喷射电沉积技术制备了不同调制周期(λ)的Ni/Co纳米多层镀层,并对镀层的表面形貌与组织、显微硬度、耐磨损性能进行了测试与分析。结果表明:多层镀层各层之间有明显界限,镀层致密均匀,与低碳钢结合牢固;随着λ的减小,Ni/Co多层镀层表面越来越致密,镀层越来越平整;Ni/Co多层镀层结构的硬度和耐磨性明显优于纯Co镀层和纯Ni镀层;λ为20 nm时,Ni/Co多层镀层的硬度和耐磨损性能最好。     

Low-dimension structural properties and microindentation studies of ion-beam-sputtered multilayers of Ag/Al films

Artificially modulated silver/aluminum multilayer films with modulation wavelengths Λ between 1.35 and 21.3 nm, and total film thickness of 1 μm were prepared by ion-beam sputtering. The mechanical properties of these films were investigated by a low load muhardness indentation technique. The films displayed increased hardness as the modulation wavelength decreased. X-ray diffraction scans showed well-defined small angle peaks and satellite peaks for high angles indicating a coherent multilayer structure. The hardness enhancement as the modulation wavelength decreases may be partially attributed to the Ag₂Al formation at the interfaces. The high quality of the well-defined layer structure is confirmed by the presence of interference maxima corresponding to the number of bilayers in the low angle diffraction data for films with total film thicknessesess than 33.0 nm.     

Influence of bilayer period on the characteristics of nanometre-scale ZrN/TiAIN multilayers

In the last decade, considerable research effort was directed to the deposition of multilayer films with layer thicknesses in the nanometer range (superlattice coatings), in order to increase the performance of various cutting tools and machine parts. The goal of the present work was to investigate the main microstructural, mechanical and wear resistance characteristics of a superlattice coating, consisting of alternate multilayer ZrN/TiAIN films, with various bilayer periods (5 / 20 nm). The coatings were deposited by the cathodic arc method on Si, plain carbon steel and high speed steel substrates to be used as wear resistance surfaces. The multilayer structures were prepared by using shutters placed in front of each cathode (Zr and Ti+Al). The characteristics of multilayer structures (elemental and phase composition, texture, Vickers microhardness, thickness, adhesion, and wear resistance) were determined by using various techniques (AES, XPS, XRD, microhardness measurements, scratch, and tribological tests). A comparison with the properties of ZrN and TiAIN single-layer coatings was carried out.     

Tribological behavior of CrAlSiN/W2N multilayer coatings deposited by DC magnetron sputtering

The CrAlSiN/W₂N multilayer coatings were fabricated by DC magnetron sputtering. The bilayer periods of multilayer films were controlled in the range from 3 to 20 nm. The cross-sectional structure of multilayer and monolayer coatings was evaluated by transmission electron microscopy (TEM). The wear behavior of monolayer and multilayer coatings was investigated by a pin-on-disc tribometer. The nano-scratch tester was employed to study the crack propagation of scratched coatings. The images of wear scars were observed by optical microscopy (OM). The cross-sectional image of scratched films was analyzed by transmission electron microscopy (TEM). Owing to the nano-layered structure and higher hardness (or H/E ratio), the multilayer coatings exhibited better wear resistance than homogeneous films. The coefficient of friction of CrAlSiN/W₂N multilayer coating with a bilayer period of 8 nm was around 0.6, and that of CrAlSiN homogeneous film was about 0.8. Different crack propagation mechanisms of CrAlSiN/W₂N multilayer and CrAlSiN monolayer coatings were proposed and discussed.     

Mechanical wear behavior of nanocrystalline and multilayer diamond coatings on temporomandibular joint implants

We used microwave plasma chemical vapor deposition to deposit nanocrystalline and multilayer (nanocrystalline/microcrystalline/nanocrystalline) diamond thin films on Ti-6AI-4V substrates imitating the condyle and fossa components of the temporomandibular joint. We tested the condyle/fossa pairs for wear in a mandibular movement simulator for an equivalent of two years of clinical use. Analysis of the wear surfaces by optical microscopy, scanning electron microscopy (SEM), and Raman spectroscopy showed that damage in both the films was minimal, no loss of film occurred and the wear performance was superior for the multilayer film. Comparisons with an uncoated condyle/fossa pair showed that the coated temporomandibular joint pairs had improved wear performance.     

Characterization of multilayer films of Ti---Al---O---C---N system prepared by pulsed d.c. plasma-enhanced chemical vapor deposition

TiAlN/TiN, TiAlCN/TiAlN/TiN and TiAlON/TiAlN/TiN multilayer films were prepared on steel substrates by pulsed d.c. plasma-enhanced chemical vapor deposition (PECVD) at 823 K using gas mixtures of TiCl₄, AlCl₃, H₂, N₂, CH₄, O₂ and Ar. We studied the structural, compositional, mechanical and chemical properties of these films. Fracture cross-sections of the TiAlN and TiAlCN films showed columnar structure. On the other hand, those of the TiAlON films showed amorphous-like dense structure. X-Ray diffraction (XRD) analyses showed that the TiAlN, TiAlCN and TiAlON films had NaCl structure. The XRD peaks of the TiAlON films were broad. Glow discharge optical emission spectroscopy (GDOS) analyses proved that these films had multilayer structure. The Vickers hardness of the TiAlN/TiN, TiAlCN/TiAlN/TiN and TiAlON/TiAlN/TiN multilayer films were 2608, 2815 and 1444 Hv, respectively. These multilayer films had higher oxidation resistance and better tribological properties than the TiN single-layer films. The TiAlCN/TiAlN/TiN multilayer films showed the best wear resistance. Furthermore, these multilayer films demonstrated superior corrosion resistance in a molten aluminum alloy at 953 K. The TiAlON/TiAlN/TiN multilayer films indicated the best corrosion resistance.     

多弧离子镀与磁控溅射共沉积TiN/TiCN多层膜的高温抗氧化性能

TiN/TiCN多层膜的高温抗氧化性研究对于扩大其应用领域具有重要作用,但目前鲜见相关报道。采用多弧离子镀与磁控溅射技术以不同调制周期在304不锈钢表面共沉积TiN/TiCN多层膜。采用XRD、XPS、倒置显微镜及高温氧化试验研究了多层膜的高温抗氧化行为。结果表明:TiN/TiCN多层膜表面光滑平整、均匀致密,薄膜主要为具有Ti-(C,N)键的fcc-TiN结构;随着调制周期的减小,TiN/TiCN多层膜生长取向发生转变,且具有(111)晶面生长织构;随着氧化温度的升高,多层膜的显微硬度逐渐降低,氧化增重速率不断增大,且在700℃之后变化速率较快,薄膜的开始氧化温度约为750℃;随着调制周期的减小,多层膜TiN与TiCN界面层数量增多,促使晶粒细化,提高了其致密性,还隔断了缺陷贯穿薄膜的连续性,显著降低了薄膜的孔隙率,致使O原子扩散困难,增强了薄膜的高温抗氧化性能。     

一种TiAlN多层膜制备新方法

采用自行设计制造的离子束联合溅射系统,将磁控溅射与离子注入技术相结合,在镁合金表面形成多层TiAlN强化膜.用金相显微镜、X射线衍射仪、原子力显微镜、摩擦磨损仪等手段,研究了多层膜的表面形貌、结构和性能.结果表明,TiAlN膜膜表面光滑致密、孔隙率大大降低,粗糙度为42.28nm,由TiAlN强化相组成;成膜后耐磨性有所提高,但摩擦系数变化不大,未达到减摩作用.