刀具表面超晶格TiN/AlN纳米多层膜的制备和研究

采用脉冲多弧离子镀技术制备TiN/AlN纳米多层膜,随着调制周期的减小,稳定态六方AlN相逐渐转变成亚稳态立方AlN相,形成以TiN/AlN超晶格结构为主的超硬薄膜。与标准图谱的对比可知,TiN/AlN超晶格是AlN在模板立方TiN材料的影响下,在TiN层上以亚稳态相立方结构外延生长所形成。试验表明TiN/AlN薄膜具有良好的耐腐蚀性能以及使用寿命。     

Ti_2AlN薄膜的制备及性能表征

三元氮化物Ti_2AlN因其优良的性能而广泛被科研工作者所关注,但对Ti_2AlN薄膜材料的制备及性能研究较少。采用多弧离子镀技术和真空退火工艺制备Ti_2AlN薄膜,同时对薄膜的耐腐蚀性和高温抗氧化性进行测试及机理分析。试验结果及分析表明:在优化制备工艺下可以制备出耐腐蚀性和抗高温氧化性较好的Ti_2AlN薄膜,与TiN薄膜进行耐腐蚀性能对比,发现Ti_2AlN薄膜具有更加优良的耐腐蚀性能;与TiN薄膜抗高温氧化温度极限值550℃相比,Ti_2AlN薄膜在800℃高温时仍具有明显的抗氧化性能,Ti_2AlN薄膜在高温时表面生成具有致密连续性的Al_2O_3氧化物,使其具有优于TiN薄膜的抗氧化性能,当超过800℃时,基体和氧化层之间产生较大应力差而导致氧化层的脱落和剥离。采用多弧离子镀技术和真空退火工艺可制备出耐腐蚀性和高温抗氧化性优良的Ti_2AlN薄膜,可为Ti_2AlN薄膜的研究提供理论支撑。     

TiN涂层陶瓷刀具膜-基界面应力的试验研究

利用X射线衍射(XRD)应力分析仪测试了TiN薄膜涂层与Si3N4陶瓷刀具基体的界面残余应力状况,分析了成膜过程中应力形成的原因及对膜—基结合强度的影响。结果表明,TiN薄膜的残余应力为压应力,本征应力为张应力,应力的大小及分布对涂层刀具的硬度和膜—基结合强度有明显影响。     

20CrNiMo钢表面磁控溅射制备TiN/ZrN多层薄膜的形貌及摩擦学性能

利用非对称双极脉冲磁控溅射技术在20CrNiMo钢表面制备了TiN/ZrN多层薄膜,利用扫描电子显微镜和原子力显微镜观察了薄膜的截面和表面形貌,用划痕仪测试了薄膜与基体的结合力,通过球-盘摩擦磨损试验机对薄膜的摩擦学性能进行了研究。结果表明:制备的TiN/ZrN多层薄膜厚度约为2.1μm,薄膜均匀且致密,表面粗糙度为13.63nm;薄膜与基体结合较牢固,临界载荷达到51.0N;薄膜具有优良的减摩性,摩擦因数为0.16,较基体20CrNiMo钢的0.33明显减小,使该钢的耐磨性能得到提高。     

硬质合金基体FCVA沉积TiAlN薄膜的试验研究

采用磁过滤阴极真空弧源(FCVA)沉积技术,通过改变氮气流量在硬质合金基体上沉积了TiAlN薄膜,用显微硬度计测定了TiAlN薄膜的硬度和厚度;采用X射线衍射(XRD)分析技术进行了TiAlN薄膜的相分析;并进行了摩擦磨损试验和对基体与薄膜的结合力进行定性的分析。结果表明:TiAlN薄膜厚度在450~520nm之间;最高硬度为2754Hv,对应氮气分压为N2分压在8.0×10-2Pa~1.1×10-1Pa;薄膜中主要存在Ti2AlN、Ti2N与TiN相。     

反应等离子喷涂TiN/AlN涂层的性能研究

TiN涂层可以通过传统的物理或者化学气相沉积（PVD及CVD）工艺制备,但其缺点是沉积速率低,涂层厚度过薄;这些都严重地限制了TiN涂层材料在磨、蚀服役条件下的应用.本文利用反应等离子喷涂的方法制备了TiN/AlN涂层并研究分析了涂层的组织及摩擦磨损性能.结果表明：TiN/AlN涂层韧性比TiN涂层有所提高;TiN/AlN涂层不仅有较低的摩擦系数,且在高载下的磨损性能比TiN涂层有较大的提高.     

磁控溅射TiN薄膜低温沉积技术及其摩擦学性能研究

利用磁控溅射装置在高速钢基体上制备了TiN薄膜,研究了基体温度升高的原因及其磁控溅射的低温原理,讨论了低温与离子刻蚀、负偏压、磁场强度3个主要溅射工艺参数的关系,并对TiN薄膜的摩擦学性能进行了研究。实验结果表明,离子刻蚀、负偏压、磁场强度对低温磁控溅射TiN成膜过程具有较大的影响,所制备的TiN薄膜的耐磨性、配副适应性也较好。     

TiN复合渗镀层摩擦磨损性能的研究

介绍了一种同时利用等离子尖端放电、空心阴极效应和反应气相沉积技术,在碳钢表面形成具有扩散层和沉积层的TiN复合渗镀层新工艺技术。对TiN复合渗镀层、TiN复合渗镀层+TiN薄膜(PVD法)以及在碳钢基体表面直接沉积TiN薄膜(PVD法)这三种工艺试样的表面形貌、硬度、摩擦磨损进行了对比研究。结果表明TiN复合渗镀层+TiN薄膜,其表面形貌是较为均匀、致密、细小的胞状物组织,平均硬度达到2500HV左右,磨损曲线最平稳、平均摩擦系数最小,耐磨性比较好。复合渗镀层厚度可达十几微米以上,并且成分、硬度、结构均呈梯度分布,与基体是冶金结合,结合力非常好,所以其磨痕最浅。     

TiN涂层残余应力对其界面结合强度的影响

用X射线衍射法测试了40Cr基体表面生成的TiN涂层结合界面残余应力,并利用划痕试验法测试了TiN涂层的结合强度,建立了残余应力与结合强度的定性关系。试验结果表明,TiN涂层残余应力对其结合强度有明显的影响,涂层残余应力越大,其结合强度越小,在涂层制备程中减小残余应力,有利于提高其结合强度。     

NiTi合金表面改性及其微动磨损性能研究

采用多弧离子镀技术在NiTi形状记忆合金表面制备TiN涂层。利用SRVⅢ摩擦磨损试验机研究NiTi合金表面改性后在37℃Hank’s模拟体液中微动磨损性能,分析法向载荷对TiN合金磨损机制的影响规律。利用SEM扫描电镜及能谱考察磨损表面形貌,结果表明：制备的TiN涂层表面致密均匀,无明显缺陷。说明TiN涂层可有效提高基体的耐磨性能,其磨损机制主要表现为剥落损伤与磨粒磨损并存。TiN涂层显微硬度为784 HV,远高于基体,TiN/NiTi膜基硬度比缓慢下降,涂层与基体结合强度高。     

刀具表面超晶格TiN／AIN纳米多层膜的制备和研究

采用脉冲多弧离子镀技术制备TiN／AIN纳米多层膜，随着调制周期的减小，稳定态六方AIN相逐渐转变成亚稳态立方AIN相，形成以TiN／AIN超晶格结构为主的超硬薄膜。与标准图谱的对比可知，TiN／AIN超晶格是AIN在模板立方TiN材料的影响下，在TiN层上以亚稳态相立方结构外延生长所形成。试验表明TiN／AIN薄膜具有良好的耐腐蚀性能以及使用寿命。     

电弧离子镀沉积TiN/AlN-TiAlN复合膜的耐磨性

采用高纯铝、钛靶材,通过电弧离子镀工艺在TC4基材上沉积制备了TiN/AlN-TiAlN复合多层膜,用HV-1000型显微硬度计测试了膜层的硬度,用球盘磨损试验对比研究了膜层和基材的耐磨性。结果表明:膜层硬度为2856HV,耐磨性相比基材提高6倍以上。     

Nanomechanical characterization of multilayered thin film structures for digital micromirror devices

The digital micromirror device (DMD), used for digital projection displays, comprises a surface-micromachined array of up to 2.07 million aluminum micromirrors (14 μm square and 15 μm pitch), which switch forward and backward thousands of times per second using electrostatic attraction. The nanomechanical properties of the thin-film structures used are important to the performance of the DMD. In this paper, the nanomechanical characterization of the single and multilayered thin film structures, which are of interest in DMDs, is carried out. The hardness, Young's modulus and scratch resistance of TiN/Si, SiO₂/Si, Al alloy/Si, TiN/Al alloy/Si and SiO₂/TiN/Al alloy/Si thin-film structures were measured using nanoindentation and nanoscratch techniques, respectively. The residual (internal) stresses developed during the thin film growth were estimated by measuring the radius of curvature of the sample before and after deposition. To better understand the nanomechanical properties of these thin film materials, the surface and interface analysis of the samples were conducted using X-ray photoelectron spectroscopy. The nanomechanical properties of these materials are analyzed and the impact of these properties on micromirror performance is discussed.     

Surface quality improvement of EDMed Ti–6Al–4V alloy using plasma etching and TiN coating

This paper seeks to improve the surface quality of electrical discharge machining (EDM) Ti–6Al–4V using plasma etching treatment and TiN coating. The EDM parameter setting is optimized firstly based on grey-Taguchi method. Four EDM parameters, including current (A), voltage (V), pulse duration (μs), and duty factor (%), are selected for multiple performance of lower electrode wear rate (EWR), higher material removal rate (MRR), and better surface roughness (SR). An orthogonal array, signal-to-noise (S/N) ratios, and analysis of variance (ANOVA) are used to analyze the effects of these EDM parameters. Normality tests show that all the distributions fit normality assumption with p?=?0.276, 0.688, and 0.663, respectively. The EDM process is stable over time monitored by Shewhart control charts. It is observed that there is an EDM damaged layer on the surface consisting of debris, microcracks, molten drops, and solidified metals by scanning electron microscopy. The plasma etching and TiN coating are employed to improve surface quality of the EDMed Ti–6Al–4V alloys. The results demonstrate that using the oxygen plasma etching treatment, the damaged phenomena are decreased, and the mean SR value is reduced from Ra?=?2.91 to Ra?=?2.50 μm. In addition, when the plasma-treated alloy is coated with Ti buffer/TiN coating by physical vapor deposition, the surface morphology exhibits less defects and a better surface finish. The mean SR values are further reduced from Ra?=?2.50 μm to Ra?=?1.48 μm (for 740 nm TiN film) and Ra?=?0.61 μm (for 1450 nm TiN film), respectively.     

Tribological performance evaluation of (1 1 1) preferred oriented TiN duplex coatings

The duplex surface coating of hot work tool steel, which comprises nitriding of a substrate and coating of a TiN layer, has been the subject of a series of studies as a potential surface modification for tools and machine parts. Through sliding experiment against an aluminum alloy without lubrication, it was shown on a wear map that there are two domains depending on sliding conditions: the wear domain and the transfer domain. In this study, focusing on the improvement in the tribological properties of the duplex coating in terms of the wear domain, the effects of film characteristics on film resistance to erosion wear and film life were investigated. Two kinds of duplex coatings with different film characteristics were prepared by hollow cathode discharge ion plating: a newly developed TiN film with a strong (1 1 1) orientation and an ordinary TiN film with (1 1 1) and (2 0 0) orientations. The erosion wear rate of duplex coating was evaluated by a micro slurry jet erosion test. Film life was evaluated by a sliding test against an aluminum alloy as in previous experiments. It was revealed that the duplex coating with the newly developed TiN film (N-coating) shows higher erosion resistance than previously reported duplex coating (C-coating). From the sliding test, it was also revealed that the N-coating whose XRD intensity ratio of (1 1 1) to (2 0 0) is over 100 shows a wear mode with only chipping, with no scratching, which shortens film life. The film life of N-coating increases about twice as long as C-coating, which has shown higher performance than a conventional duplex coating. Possible mechanisms of the improvement in the tribological properties with N-coating are discussed.     

Friction and Wear Properties of Graphite-Like Carbon Films Deposited on Different Substrates with a Different Interlayer Under High Hertzian Contact Stress

Four types of graphite-like carbon (GLC) films were deposited on different substrates (Ti6Al4V, WC-27CrNi) with a different interlayer (TiC/Ti, TiC/Ti/TiN) using an unbalanced magnetron sputtering system. The effect of substrate and interlayer on the microstructure and properties of the studied GLC films was then investigated using different characterization techniques. The results show that both the substrate and interlayer had an obvious influence on the tribological properties of the studied GLC films even though there was no significant structural difference between these films. Specifically, a substrate with a high hardness was propitious to achieving superior tribological behaviors for carbon film even with a different interlayer. However, the interlayer had a distinct influence on the tribological properties of the carbon film deposited on different substrates, and this effect varied with the hardness property of the substrate. For a hard substrate, the wear rate and wear life were similar irrespective of the interlayer. For a soft substrate, the addition of a TiN interlayer improved the wear life sevenfold compared to the film with only a TiC/Ti interlayer, but the wear rate for a film with and without a TiN interlayer was approximately the same. The obvious discrepancy between wear life and wear rate for a carbon film deposited on soft substrate was closely related with the film adhesion strength and plastic deformation of the substrate materials. Based on these results, it can be concluded that the wear life is a better parameter than wear rate in terms of characterization of the wear resistance of carbon film once the applied load causes the plastic deformation of the substrate.     

Cr12MoV钢表面磁控溅射TiB2-TiN薄膜的摩擦磨损性能

采用磁控溅射技术在淬火态Cr12MoV表面制备SiC/TiN、SiC/TiB2-TiN薄膜(SiC为中间层),研究TiN、TiB2-TiN薄膜的组织结构和摩擦磨损性能。结果表明,SiC薄膜与基材和TiN、TiB2-TiN薄膜间都具有明显的且呈梯度的元素扩散,界面结合良好。在水润滑条件下与钢球对摩时(载荷0.5 N,时间0.5 h),TiN薄膜、TiB2-TiN薄膜具有良好摩擦磨损性能,其平均摩擦因数分别为0.33、0.31,低于淬火态Cr12MoV的0.45,磨损速率分别为2.0×10-8和1.5×10-8mm3/(N.m),低于淬火态Cr12MoV的8.66×10-7mm3/(N.m),其中在水润滑条件下TiB2-TiN薄膜比TiN薄膜具有更好的摩擦磨损性能。