中频磁控溅射周期性变电流（Ti，Al）N多层薄膜的结构与性能

使用独特的镶拼矩形TiAl靶,用中频反应磁控溅射方法,采用周期性改变靶电流的方法在高速钢(W18Cr4V)基体上沉积了(Ti,Al)N多层薄膜.利用场发射扫描电镜、纳米硬度仪和x射线衍射仪等方法研究了(Ti,Al)N多层薄膜组织结构、硬度和膜基结合性能.结果表明,制备的(Ti,Al)N多层薄膜硬度略低于20GPa.弹性模量均大于230GPa,薄膜的临界载荷均大于50N;多层薄膜有一定的择优取向,且择优取向随着靶电流周期性的改变而有所变化.同时发现,(Ti,Al)N多层薄膜硬度是结构、界面和择优取向共同作用的结果.     

AlN/VN纳米多层膜的共格生长与超硬效应

研究了亚稳相立方AlN(c-AlN)在AlN/VN纳米多层膜中的形成条件以及c-AlN对纳米多层膜力学性能的影响。一系列不同调制周期的AlN/VN多层膜采用反应磁控溅射法制备,多层膜的微结构采用小角度X射线衍射和高分辨电子显微镜表征,利用微力学探针测量了多层膜的力学性能。结果表明：亚稳的c-AlN因VN的“模板”作用生成于小调制周期的纳米多层膜中,并与VN形成共格外延生长的超晶格柱状晶,从而使多层膜产生硬度和弹性模量升高的超硬效应。随调制周期的增大,c-AlN转变为稳定的六方结构(h-AlN),使多层膜形成纳米晶的“砖墙”型结构。此时多层膜的硬度和弹性模量与混合法则所得值相当。AlN/VN纳米多层膜在小调制周期下产生的超硬效应与c-AlN形成带来的性质变化以及c-AlN与VN形成共格结构所产生的界面交变应变场有关。     

多弧离子镀制备纳米多层TiAlSiN涂层的性能研究

采用多靶阴极电弧离子镀系统在硬质合金基体上沉积纳米多层结构的Ti Al Si N硬质涂层,该结构是通过Ti Al N涂层与Ti Si N涂层的交替叠加而制备的。实验同时制备了Ti Al N涂层、Ti Al Si N单层涂层与纳米多层涂层进行性能对比分析,用扫描电镜(SEM)、EDS对涂层结构形貌及成分进行了分析,用划痕法和纳米压痕法分别对涂层的结合力与纳米硬度进行了测试,同时也测试了涂层在不锈钢车削上的性能表现。结果表明,Ti Al Si N纳米多层涂层硬度高达33 GPa,同时在不锈钢车削上以Ti Al Si N纳米多层涂层性能最优,而Ti Al Si N单层涂层性能最差。     

溅射工艺参数对TiAlN薄膜力学性能及结构成分的影响

采用反应磁控溅射法和钛一铝镶嵌靶制备TiAlN薄膜;运用纳米压入硬度测试仪、划痕仪和能谱仪、X射线衍射仪等对薄膜进行表征;研究了制备工艺参数对薄膜力学性能、薄膜成分及组织结构的影响.结果表明:随着氮气分压增大,薄膜厚度降低,薄膜(111)取向减弱,(220)和(311)取向增强,薄膜中的氮原子含量逐渐增多,而钛、铝原子含量逐渐减少;随着基体偏压增大,薄膜纳米硬度和膜/基界面临界载荷均逐渐增大,纳米硬度最高可迭48.73 GPa,膜/基界面临界载荷最高可达40 N.     

AFM的纳米硬度测试与分析

基于原子力显微镜(AFM)和金刚石针尖建立了一套纳米压痕测量系统。通过向系统发送控制电压使金刚石针尖在完成加载和卸载全过程的同时进行实时的数据采集并直接绘出载荷-压深曲线。利用该系统,对单晶铝和单晶铜薄膜材料进行了单点压痕实验,用美国Hysitron公司的纳米原位测量仪(TriboIndenter)做了验证试验。实验结果表明,该系统适合测量较软材料的纳米硬度。分析了基体材料对薄膜硬度和弹性模量的影响,在薄膜厚度低于5~10倍压入深度时,基体对薄膜材料的力学性能影响很大;并根据获得的载荷－压深曲线分析得出由于尺度效应的影响,随着压痕深度的减小,薄膜的硬度值呈明显的上升趋势,弹性模量没有这个趋势。     

应用纳米压痕法测试类金刚石薄膜的力学性能

纳米压痕仪被称为材料机械性质微探针,它借助于加载-卸载过程中压痕对载荷和压入深度的敏感关系,使得测试始终在薄膜材料的弹性限度内,克服了维氏法和努氏法等传统方法引起压痕边缘模糊或者碎裂的缺点,从而正确地、可靠地测试出薄膜材料的硬度和弹性模量等纳米力学性能.试验用微波电子回旋共振等离子体增强化学气相沉积技术,在不同偏压条件下制备三种类金刚石薄膜(DLC膜),用纳米压痕仪测试不同载荷下薄膜的硬度和弹性模量值.试验结果表明,材料的纳米硬度和弹性模量随着载荷的增大而逐渐减小.     

薄膜/基体结构的纳米压痕实验及其有限元分析

利用纳米压痕实验测定了氮化钛薄膜/高速钢基体中薄膜的弹性模量和硬度,并得到了纳米压痕过程的载荷—位移曲线;根据实验所得材料参数建立了纳米压痕实验的DEFORM计算模型,利用该有限元模型分析了不同薄膜厚度的膜/基结合处的切应力分布,研究了膜/基分离的可能性大小及分离位置与薄膜厚度的关系。     

溅射工艺参数对TiAIN薄膜力学性能及结构成分的影响

采用反应磁控溅射法和钛-铝镶嵌靶制备TiAIN薄膜；运用纳米压入硬度测试仪、划痕仪和能谱仪、X射线衍射仪等对薄膜进行表征；研究了制备工艺参数对薄膜力学性能、薄膜成分及组织结构的影响。结果表明：随着氮气分压增大，薄膜厚度降低，薄膜（111）取向减弱，（220）和（311）取向增强，薄膜中的氮原子含量逐渐增多，而钛、铝原子含量逐渐减少；随着基体偏压增大，薄膜纳米硬度和膜／基界面临界载荷均逐渐增大，纳米硬度最高可达48．73GPa，膜／基界面临界载荷最高可达40N。     

纳米硬度技术在表面工程力学性能检测中的应用

结合纳米硬度技术测量各类薄膜和块体材料表层的纳米压痕硬度、弹性模量、断裂韧性、膜厚、微结构的弯曲变形，采用纳米划痕硬度技术测量各类薄膜和块体材料的粗糙度、临界附着力、磨擦系数、划痕横剖面。纳米硬度计是检测材料表层微米乃至几十纳米力学性能的先进仪器，可广泛应用于表面工程中的质量检测。     

17-4PH不锈钢表面TiO_2膜及其多层膜的结构与性能

利用非平衡磁控溅射技术在17-4PH不锈钢表面分别制备了TiO_2膜、TiO_2/Ti多层膜及TiO_2/Ti/TiN/Ti多层膜,采用XRD、表面轮廓仪、显微硬度仪、摩擦磨损试验机和水蒸气疲劳腐蚀试验设备研究了薄膜的物相、显微硬度、耐磨性和耐疲劳腐蚀性能。结果表明:具有表面薄膜17-4PH不锈钢的硬度、耐磨性和耐腐蚀性能均有较大提高;与TiO_2膜和TiO_2/Ti/TiN/Ti多层膜相比,TiO_2/Ti多层膜耐磨性能最好,较基体的提高了20倍以上,同时其耐疲劳腐蚀性能也最好。     

FCVA沉积TiAlN薄膜的工艺研究

采用磁过滤阴极真空弧源(FCVA)沉积技术,在高速钢(HSS)基体上沉积TiAlN薄膜,用显微硬度计测定TiAlN薄膜的硬度和厚度,用X射线衍射(XRD)分析技术进行TiAlN薄膜的相分析并进行了摩擦磨损实验,为在刀具表面沉积TiAlN薄膜打下较好的工艺基础。     

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。     

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.     

A method for the tribological testing of thin,hard coatings

A new method has been developed for tribological testing of thin, hard antiwear coatings, using a ball‐on‐disc tribosystem, under conditions of dry sliding. In this, an Al₂O₃ ball is pressed against a coated steel disc. Wear debris is removed from the contact zone by a stream of dry argon in this novel method. This improves the stability of the tribological properties and the repeatability of the test results. All test conditions are precisely defined, in particular: the type of motion, air relative humidity, ambient temperature, sliding speed, load, tribosystem spatial configuration, substrate material, substrate hardness and roughness, and coating thickness. The method developed has been used to test various physical vapour deposition coatings (deposited by the vacuum arc method), i. e., single‐layer TiN, Ti(C,N), CrN, and Cr(C,N), and multilayer Cr(C,N)/CrN/Cr and Cr(C,N)/(CrN+Cr₂N)/CrN/Cr. It is shown that CrN coatings exhibit the best antiwear properties, and Ti(C,N) the worst. Friction coefficients for CrN and Cr(C,N) coatings are much lower than for the more commonly used TiN. Multilayer coatings have better antiwear properties than single‐layer ones.     

纳米压入法测试薄膜力学性能的若干关键影响因素分析

纳米压入法是目前薄膜等小体积MEMS(micro-electro-mechanical system)材料力学性能评定广为使用的方法,其测试可靠性严重依赖于仪器校准及对各种误差影响因素的消除和修正.文中以Oliver-Pharr数学评定模型为基础,对包括仪器柔度、压尖几何形状偏差、初始接触点位移、尺寸效应、基底、堆积和凹陷、蠕变、表面粗糙度等在内的薄膜弹性模量和硬度纳米压入测试时的若干关键影响因素进行分析.在此基础上,分别给出相应的处理办法和数据修正措施.研究表明,只有综合考虑这些因素的影响,方能获得准确的薄膜本征力学性能参数.     

微米/纳米Ti(C,N)基金属陶瓷刀具材料的研制

在试验的基础上系统研究了纳米级Al2O3的含量对Ti(C,N)基金属陶瓷力学性能和显微结构的影响。结果表明,纳米Al2O3的添加可大幅提高Ti(C,N)基金属陶瓷的力学性能,特别是硬度和断裂韧性明显提高,克服了Ti(C,N)基金属陶瓷硬度较低的缺点,扩大了其应用范围。通过对材料微观结构的观察和分析,认为纳米Al2O3的添加细化了基体晶粒,主要断裂模式为穿晶断裂,晶粒的细化和断裂模式的改变是材料力学性能提高的主要原因。     

Analysis of thermal diffusivity of Ti thin film by thermoreflectance and periodic heating technique

Thermal diffusivity of Ti thin film with several hundred nanometers thickness has been measured by means of thermoreflectance (TR) technique and periodic heating using front heating and front detection configuration. Ti thin films were prepared on Si substrates by dc sputtering method. Then thin Mo layers as reflection layers were coated on Ti thin films. Surface of the Mo layer is irradiated by sinusoidally intensity modulated heating laser. Temperature response at the heated area is measured by a probe laser beam with constant intensity, as a TR signal. Phase lag between the phase of TR signal and that of heating laser beam was obtained from 100 kHz to 2.6 MHz. To analyze thermal diffusivity of Ti thin films using the phase lag data, we developed a three-layer analytical model such as Mo coating (100 nm)∕thin film∕semi-infinite substrate. The calculated phase lag using analytical model is in good agreement with the experimental data for the whole frequency range. The thermal diffusivity of two Ti thin films is determined to be 5 × 10(-6) m(2)∕s, which is 53% of the bulk one.     

TiN/Ti涂层在波箔轴承中的摩擦磨损性能

采用真空离子镀的方法在304不锈钢基体上喷涂厚度为3μm的TiN/Ti薄层,利用硬度计、三维形貌仪、划痕试验仪对涂层基本力学性能进行分析,通过球盘试验机分析涂层试样的摩擦磨损性能,根据波箔轴承性能测试实验台的测试结果:研究TiN/Ti涂层对基体表面耐磨减摩性能的影响。研究结果表明:TiN涂层硬度可达HV1500,是基材硬度的5.5倍;TiN/Ti涂层平均摩擦因数为0.23,相对不锈钢304基材的平均摩擦因数0.71,降低了68%,磨损量也仅为基材的18.75%;GCr15与PTFE对磨的最大摩擦力矩可达2.4 N·mm,而TiN/Ti与PTFE对磨的最大摩擦力矩仅为1 N·mm,仅为GCr15的41.7%。TiN/Ti涂层表现出了优异的承载能力和耐磨减摩性能。     

Wear resistant multilayer nanocomposite WC1−x/C coating on Ti–6Al–4V titanium alloy

A significant improvement of tribological properties on Ti–6Al–4V has been achieved by developed in this study multilayer treatment method for the titanium alloys. This treatment consists of an intermediate 2 μm thick TiC_xN_y layer which has been deposited by the reactive arc evaporation onto a diffusion hardened material with interstitial O or N atoms by glow discharge plasma in the atmosphere of Ar+O₂ or Ar+N₂. Subsequently, an external 0.3 μm thin nanocomposite carbon-based WC_1−x/C coating has been deposited by a reactive magnetron sputtering of graphite and tungsten targets. The morphology, microstructure, chemical and phase compositions of the substrate material after treatment and coating deposition have been investigated with use of AFM, SEM, EDX, XRD, 3D profilometry and followed by tribological investigation of wear and friction analysis. An increase of hardness in the diffusion treated near-surface zone of the Ti–6Al–4V substrate has been achieved. In addition, a good adhesion between the intermediate gradient TiC_xN_y coating and the Ti–6Al–4V substrate as well as with the external nanocomposite coating has been obtained. Significant increase in wear resistance of up to 94% when compared to uncoated Ti–6Al–4V was reported. The proposed multilayer system deposited on the Ti–6Al–4V substrate is a promising method to significantly increase wear resistance of titanium alloys.