基片与膜厚对硬质薄膜力学性能的影响

采用毫牛力学探针技术的两步压入试验法研究了高速钢和不锈钢基片上不同厚度TiN薄膜的硬度和弹性模量。结果表明：采用同样工艺制备的TiN薄膜，其力学性能随基片类型和膜厚的不同有明显变化。薄膜的硬度和弹性模量随膜厚的增加而提高；基体硬度的提高也使薄膜呈现较高的硬度和模量。分析认为薄膜内应力状态的改变是产生这些现象的主要原因。     

TiN/Si3N4纳米多层膜的生长结构与超硬效应

采用磁控溅射方法制备了一系列不同Si3N4和TiN层厚的TiN/Si3N4纳米多层膜,采用X射线衍射、高分辨电子显微分析和微力学探针表征了薄膜的微结构和力学性能,研究了Si3N4和TiN层厚对多层膜生长结构和力学性能的影响.结果表明:当Si3N4层厚小于0.7 nm时,原为非晶的Si3N4在TiN的模板作用下晶化并与之形成共格外延生长的柱状晶,使TiN/Si3N4多层膜产生硬度和弹性模量异常升高的超硬效应.最高硬度和弹性模量分别为34.0 GPa和353.5 GPa.当其厚度大于1.3 nm时,Si3N4呈现非晶态,阻断了TiN的外延生长,多层膜的力学性能明显降低.此外,TiN层厚的增加也会对TiN/Si3N4多层膜的生长结构和力学性能造成影响,随着TiN层厚的增加,多层膜的硬度和弹性模量缓慢下降.     

基于SVR的脉冲激光沉积TiN/AlN多层薄膜的工艺优化

根据脉冲激光沉积(PLD)法在单晶Si试样表面沉积制备多层TiN/AlN硬质膜实验数据,应用基于粒子群算法(PSO)寻优的支持向量回归(SVR)方法,建立不同工艺参数下沉积的TiN/AlN多层膜的AlN膜厚及TiN薄膜硬度的SVR预测模型。在相同的训练与测试样本集下,将SVR所得的AlN膜厚预测值与免疫径向基函数(IRBF)神经网络的计算结果进行比较。结果表明,SVR模型训练和预测结果的平均绝对百分误差要比IRBFNN模型的小,其预测精度更高,预测效果更好。应用SVR的TiN薄膜硬度模型对PLD法沉积TiN薄膜的工艺参数进行了优化,分析了多因素对PLD法沉积TiN薄膜硬度的交互作用和影响。该方法可为人们利用PLD法沉积TiN/AlN多层功能薄膜提供科学的理论指导,具有重要的理论意义和实用价值。     

厚度对TiN薄膜力学性能的影响

采用电弧离子镀方法制备了不同厚度TiN薄膜,并对其硬度、结合力、残余应力、摩擦磨损特性等力学性能进行了系统性研究,以揭示硬质薄膜厚度对其力学性能的影响规律。结果表明,随着厚度增加,薄膜表面大颗粒增加,膜基界面剪切力增大,薄膜硬度逐渐增加,结合力逐渐下降,摩擦系数略有下降;而薄膜应力沿层深分布趋势基本一致,都呈钟罩形分布;磨损率随薄膜厚度变化不大,即薄膜越厚越耐磨。     

磁控共溅射制备氮化钛铝薄膜及其机械性能的研究

使用磁控共聚焦溅射技术并改变溅射过程中Al的功率来制备了一系列Al含量不同的氮化钛铝（TiAlN）薄膜。在溅射过程,薄膜沉积速率和Al含量随Al的溅射功率增加而增大,而薄膜的粗糙度减小。Al含量较低时（约21％）,TiAlN薄膜的硬度和弹性模量都高于TiN薄膜。而Al含量较高时（〉26％）,薄膜的硬度和弹性模量也随含量增加减小。     

调制结构对TiN/ZrN纳米多层膜的表面形貌、生长行为及力学性能的影响

利用射频反应磁控溅射方法,设计并制备了一系列不同调制周期的TiN/ZrN纳米多层膜.利用原子力显微镜、X射线衍射仪和纳米压痕仪对多层膜的表面形貌、微观结构和力学性能进行了系统表征.研究结果表明调制结构影响着薄膜的择优生长取向、沉积速率和表面形貌;在调制周期为7nm～26nm的范围内,随调制周期的增加,TiN/ZrN多层膜的织构取向有从(100)面向(111)面转变的趋势;TiN和ZrN层的沉积速率随调制周期的变化而变化.在调制周期为15nm左右时,表面粗糙度最小,减小和增加调制周期均导致粗糙度的增加.力学性能分析表明TiN/ZrN多层膜的硬度和弹性模量均高于单一TiN和ZrN的硬度和弹性模量,且随着调制周期的减小有逐渐增加的趋势.此外,根据调制结构和力学性能的分析结果,讨论了TiN/ZrN纳米多层膜的硬化机制.     

轴向磁场对电弧离子镀TiN/Cu薄膜性能的影响

使用加可调轴向磁场的电弧离子镀设备在不锈钢基体上制备TiN/Cu薄膜,研究了轴向磁场强度对薄膜微观结构、化学成分、力学性能和耐磨性能的影响。结果表明,在不同强度的磁场下TiN/Cu薄膜具有相同的TiN结构,且以沿TiN(111)面的择优取向为主。随着磁场强度的提高(111)面衍射峰的强度逐渐提高、TiN/Cu薄膜表面的粗糙度先降低后提高、薄膜中Cu的含量逐渐提高、硬度和弹性模量也逐渐提高、薄膜的磨损率先降低后提高。当磁场强度为80 Gs时薄膜的硬度达到约为36 GPa的最大值,耐磨性能最高。     

氨气还原氮化法制备TiN薄膜及其SERS效应研究

以四氯化钛乙醇溶液为钛源,采用氨气还原氮化法成功制备了TiN薄膜,利用XRD、RAMAN、FE-SEM、TEM、SAED及UV-VIS-NIR表征薄膜结构及光学性能。结果表明,TiN薄膜为NaCl型面心立方TiN晶体,膜厚在250nm左右。UV-VIS-NIR分析显示TiN薄膜在500nm附近出现了特征表面等离子体共振吸收峰。利用R6G作为探针分子研究了TiN薄膜拉曼增强效应,结果发现,TiN薄膜具有显著的拉曼增强效应,与空白石英基片相比,TiN薄膜对R6G增强因子为6.08×10~3,检出限为10~(-6) mol/L。     

TiN/NbN纳米多层薄膜的交变应力场和超硬效应

为了研究纳米多层薄膜的超硬效应 ,采用反应溅射法制备从 1 4nm至 2 7nm不同调制周期的一系列TiN/NbN纳米多层膜。高分辨电子显微镜对薄膜的调制结构和界面生长方式的观察发现 ,TiN/NbN膜具有很好的调制结构 ,并呈现以面心立方晶体结构穿过调制界面外延生长的多晶超晶格结构特征。显微硬度测量表明 ,TiN/NbN纳米多层膜存在随调制周期变化的超硬效应。薄膜在调制周期为 8 3nm时达到HK39 0GPa的最高硬度。分析认为 ,两种不同晶格常数的晶体外延生长形成的交变应力场 ,对材料有强化作用 ,这是TiN/NbN纳米多层膜产生超硬效应的主要原因     

辉光弧光协同共放电方式制备TiN薄膜的研究

分别采用中频磁控溅射、电弧离子镀及辉光弧光协同共放电混合镀(APSCD)三种方式在碳钢基体上制备TiN薄膜,采用原子力学显微镜、显微硬度计、台阶膜厚仪、电化学技术对薄膜表面形貌、显微硬度、膜厚、耐腐蚀性进行测试.研究结果表明:多弧离子镀薄膜颗粒的平均粗糙度为7.066 nm,混合镀薄膜颗粒的平均粗糙度为4.687 nm,在相同时间条件下,磁控溅射薄膜厚度为658 nm,混合镀膜厚度为1345 nm,混合镀工艺具有降低多弧离子镀粗糙度又可以克服磁控溅射沉积速率慢的优点.经过混合镀TiN薄膜后,基体表面显微硬度从226HV提高到1238 HV,在天然海水中测得混合镀膜层腐蚀电位比基体提高104 mV.     

Microstructural characteristics and mechanical properties of magnetron sputtered nanocrystalline TiN films on glass substrate

Nanocrystalline TiN thin films were deposited on glass substrate by d.c. magnetron sputtering. The microstructural characteristics of the thin films were characterized by XRD, FE-SEM and AFM. XRD analysis of the thin films, with increasing thickness, showed the (200) preferred orientation up to 1·26 μm thickness and then it transformed into (220) and (200) peaks with further increase in thickness up to 2·83 μm. The variation in preferred orientation was due to the competition between surface energy and strain energy during film growth. The deposited films were found to be very dense nanocrystalline film with less porosity as evident from their FE-SEM and AFM images. The surface roughness of the TiN films has increased slightly with the film thickness as observed from its AFM images. The mechanical properties of TiN films such as hardness and modulus of elasticity (E) were investigated by nanoindentation technique. The hardness of TiN thin film was found to be thickness dependent. The highest hardness value (24 GPa) was observed for the TiN thin films with less positive micro strain.     

Indentation of a hard film on a compliant substrate: film fracture mechanisms to accommodate substrate plasticity

In this paper we discuss various contact damage modes in thin TiN films on steel substrate with increasing load. To understand the displacement at different points along the depth of the film, we have used a TiN–AlTiN multilayered film in which each layer acts as a strain marker and we have also calculated the stresses theoretically using an elastic model of spherical indentation of a bi-layer. The study has helped to understand the physics behind different fracture phenomena, such as confinement of columnar sliding to the middle of the film, the genesis of lateral cracks during unloading, etc. We also emphasize the co-existence and competition of different modes of fracture in the film, rather than a single mode, at a particular combination of film thickness, substrate hardness and load and describe the way different modes interact in the spatial domains when they do coexist.     

奥氏体不锈钢表面硬质薄膜的制备与性能研究

用磁控溅射法在奥氏体不锈钢基片上分别制备了TiN薄膜和Al2O3薄膜,并用XRD、SEM和显微硬度等测试手段对沉积态和退火态薄膜进行表征,分析了不同工艺参数对薄膜的沉积速率、结构和性能的影响,从而得到最佳工艺参数。TiN薄膜在沉积气压为1．5Pa,氩氮比为16：16时薄膜的硬度值最大为16．0GPa。Al2O3薄膜在沉积气压为0．5Pa,氩氧比为10：1时薄膜的硬度值可达25．2GPa。     

在室温条件下制备高质量纳米结构TiN薄膜研究

在室温条件下,利用磁过滤等离子体在单晶硅和不锈钢表面上制备了性能优异的纳米结构TiN薄膜.运用原子力显微镜和掠角入射X射线衍射仪对其结构与形貌进行了表征,利用纳米压痕仪测量了TiN薄膜的硬度和弹性模量.结果表明:TiN薄膜表面光滑,致密,无柱状晶;TiN晶粒的平均尺寸为50nm,薄膜硬度达50 GPa,是传统CVD和PVD技术沉积氮化钛的两倍多;XRD衍射试验表明,纳米TiN的衍射角都普遍向小角度移动,TiN晶粒沿(111)择优生长.     

Thick TiN films prepared by vacuum arc deposition and high energetic nitrogen ion beam dynamic mixing implantation

TiN films have many features, such as high wear resistance, high corrosion resistance and good oxidization resistance. With the technology of vacuum arc deposition and high current density nitrogen ion beam dynamic mixing implantation (DMI), the TiN film with a thickness of 33 μm and adhesion 58 N is synthesized on hard alloy and high-speed steel substrates. X-ray diffraction has been used to examine the crystal structure of the films. The results showed that the main phases presented in DMI films are TiN and Ti₂N and that the films revealed random growth. Cross-sectional scanning electron microscopy revealed the dense morphology and the thickness of the films. Micro-hardness tests showed that the average hardness of the films was about 2500 HK. Electrochemical experimental results indicated that DMI-TiN film had excellent corrosion resistance both in 3% NaCl solution and in 0.5 Mol H₂SO₄ solution.     

声发射监听划痕法评价膜层结合情况的有效性

本文介绍声发射技术在判断划痕临界载荷以推定膜层与基材结合情况的研究结果。实验的试样是玻璃基材真空蒸镀铝膜、软钢上电镀镍层以及不同硬度的钢样上离子镀超硬氮化钛膜层。在脆性硬质基材上无论镀软膜或硬膜,划痕试验中一旦监听到声发射信号即表明基材与膜层结合失效,此时的划痕载荷即为临界载荷。塑性基材镀软膜层直到划痕到基材也无声发射信号出现。超硬膜层与钢基材的划痕试验中,声发射信号出现时载荷往往低于临界载荷。两者的差值决定于超硬膜的厚度和膜层与基材的硬度差。     

Influence of bias voltages on the structure and wear properties of TiSiN coating synthesized by cathodic arc plasma evaporation

Nanocomposite TiSiN films have been deposited on M2 tool steel substrates using TiSi alloy as target by a dual cathodic arc plasma deposition (CAPD) system. The influences of bias voltages on the microstructure, mechanical and tribological properties of the films were investigated. Scanning electron microscopy, transmission electron microscopy, X-ray diffraction techniques were employed to analyse the microstructure, grain size and residual stress. Nano-indentation and tribometer testers were used to measure the mechanical and tribological properties of nanocomposite TiSiN thin films. The results showed that the hardness of the films ranged from 25 to 37 GPa, which were higher than that of TiN (21 GPa). The coefficient of friction of the TiSiN thin films was more stable but was higher than that of TiN when wear against both Cr steel and WC-Co ball, respectively. When encountered with both Cr steel and WC-Co ball of the counter ball, the tribological mechanisms of TiSiN thin films are adhesive and abrasion wears, respectively. It has been found that the microstructure, mechanical and wear properties of the films were correlated to bias voltage, grain size, and amorphous Si₃N₄ nanocomposite formed in film structure, resulting in a superhard TiSiN coating.     

Extracting thin film hardness of extremely compliant films on stiff substrates

A previously reported method for extracting the thin film hardness from nanoindentation into a film on an elastically mismatched substrate was applied to four different cases of extreme mismatch in elastic properties: Parmax, Ultem, Polysulfone and Perfluorocyclobutyl polymer thin films on Si substrates. All of these cases represent extremely compliant films on a stiff substrate, where the ratio of film shear modulus to substrate shear modulus ranged from 0.008 to 0.036. Analyzing the nanoindentation data into these film/substrate systems poses a significant limitation when using the Oliver and Pharr method as the hardness increases rapidly with indentation depth. Therefore, a method involving the measured contact stiffnesses to more accurately determine the correct contact areas was used to extract the true hardness of the polymer thin films. The results indicate that our method is able to remove the substrate effects as well as the complications arising from pile-up and surface roughness to yield a wide plateau in hardness despite the extreme elastic mismatch conditions.     

Preferred growth of epitaxial TiN thin film on silicon substrate by pulsed laser deposition

Epitaxial TiN thin films on silicon substrates were prepared by pulsed excimer laser (KrF, 34 ns) ablation of a hot-pressed TiN target in nitrogen gas atmosphere. X-ray diffraction (XRD) showed that the preferred orientations of TiN thin films did not change with substrate temperatures, nitrogen gas pressure and film thickness; however, they did change with the orientations of substrates. The epitaxial orientation relationships between high-quality epitaxial TiN thin films and silicon substrates [2 4 2] TiN [2 4 2] Si, (1 1 1) TiN(1 1 1) Si and [3 1 1] TiN [3 1 1] Si, (1 0 0) TiN(1 0 0) Si. The full-width at half-maximum (FWHM) of the rocking curve of XRD and the minimum channelling yield of Rutherford backscattered spectroscopy (RBS) of the epitaxial TiN thin film were estimated to be 0.3 ° and 7.3%, respectively, indicating excellent crystalline quality of the grown film. X-ray photoelectron spectroscopy confirmed that the binding energies of Ti 2p 3/2 and N 1s core levels in epitaxial thin film were 455.2 and 397.1 eV, respectively, corresponding to those of TiN bulk. By calibrating the RBS spectra, the chemical composition of TiN thin films was found to be titanium-rich. The typical surface roughness of TiN thin film observed by scanning probe microscopy was about 1.5 nm. © 1998 Chapman & Hall     

Hardness measurements of thin films

A simple technique is presented to obtain the characteristic microhardness values of surface coatings that are too thin for the values to be directly measured. The application of the technique requires conventional microhardness measurements on both coated and uncoated substrates and a knowledge of the film thickness. The film hardness is obtained from these data by the use of a simple formula which is based on a physical model of film deformation during indentation. The model is verified for chromium films on four different substrate materials. Hardness values of the film material can be obtained from films with a thickness of more than 2000 Å with this technique.