Wear resistant TiMoN coatings deposited by magnetron sputtering

TiMoN coatings with different Mo concentrations were deposited using a reactive magnetron sputtering technique and characterized by X-ray diffraction, nano-indentation, pin-on-disc testing, SEM/EDS and X-ray photoelectron spectroscopy. Mo alloying of TiN coatings generally enhances hardness. When tested in a pin-on-disc test against WC-Co pin, the coefficients of friction of TiMoN coatings were found to decrease with the increase in Mo atomic fraction, with the lowest values (0.4-0.5) being only one-half that of TiN coating (1.03). The underlying mechanism of the Mo effect is the formation of lubricious MoO₃ on the wear track. The combination of low coefficient of friction and enhanced hardness reduces the wear rate of TiMoN coatings to less than 2.5% of the wear rate of TiN coating.     

Tribological characterization of tungsten nitride coatings deposited by reactive magnetron sputtering

The structure, hardness, friction and wear of tungsten nitrides prepared by d.c. reactive magnetron sputtering were investigated. The coatings were deposited with different nitrogen to argon ratios; the total pressure was kept constant. The tribological tests were performed on a pin-on-disc tribometer in terrestrial atmosphere with 100Cr6 steel, Al₂O₃ and Si₃N₄ balls as sliding counter-bodies. The wear tracks, the ball-wear scars and the wear debris were analysed by scanning electron microscopy in order to characterize the dominant wear mechanisms.The coatings exhibited different phases as a function of the nitrogen content: films with low N content exhibited the α-W phase; β-W phase was dominant for nitrogen contents from 12 to 15 at.% and β-W₂N was observed for nitrogen content higher that 30 at.%. The mechanical and tribological properties of the tungsten nitride coatings were strongly influenced by the structure. The hardness and the Young's modulus values were in the ranges (29–39 GPa) and (300–390 GPa), respectively; the lowest values correspond to the coatings with the highest nitrogen content. Generally, the friction and wear rate of tungsten nitride coatings sliding against ceramic balls increased with nitrogen content reaching a maximum at 12 at.%; further increase of the nitrogen content led to a decrease of the friction and wear. The sliding with the steel balls did not wear the coatings under the selected testing conditions.     

磁控溅射技术进展及应用(上)

近年来磁控溅射技术的应用日趋广泛,在工业生产和科学研究领域发挥巨大作用。随着对具有各种新型功能的薄膜需求的增加,相应的磁控溅射技术也获得进一步的发展。本文将介绍磁控溅射技术的发展,以及闭合磁场非平衡溅射、高速率溅射及自溅射、中频及脉冲溅射等各种新技术及特点,阐述磁控溅射技术在电子、光学、表面功能薄膜、薄膜发光材料等许多方面的应用。     

磁控溅射技术进展及应用(下)

近年来磁控溅射技术的应用日趋广泛,在工业生产和科学研究领域发挥巨大作用。随着对具有各种新型功能的薄膜需求的增加,相应的磁控溅射技术也获得进一步的发展。本文将介绍磁控溅射技术的发展,以及闭合磁场非平衡溅射、高速率溅射及自溅射、中频及脉冲溅射等各种新技术及特点,阐述磁控溅射技术在电子、光学、表面功能薄膜、薄膜发光材料等许多方面的应用。     

多工位磁控溅射镀膜系统膜厚均匀性的研究

本文建立了多工位公自转磁控溅射系统镀膜过程的物理模型,通过把基片运动与镀膜过程的模拟结合在一起,运用时间步长划分的算法仿真公自转系统下矩形靶沉积的三维膜厚分布,并使用同样的方法计算纯自转磁控溅射系统沉积薄膜的厚度分布,最后将两个结果进行对比.研究表明,随着自转与公转速度比例的调节,公自转系统在最优转速比0.5时所制得的薄膜厚度均匀性较纯自转系统得到明显地改善,此结论与实验结果保持一致.     

Friction and wear response of nitride coating deposited through PVD magnetron sputtering

Surface engineering with applied coating plays a vital role in any industrial application. These coatings are meant for better mechanical and tribological characteristics when applied on to the materials. The major challenge in selecting a suitable coating strategy is their input process parameters. There are several parameters which influences the coating properties, but it is hard to choose one of them and ignoring others. Multilayers of tungsten nitride are attracting great interest to modulate their tribological and mechanical properties through physical vapour deposition process due to their wide application range. These multilayer nitride films were deposited through unbalanced reactive magnetron sputtering technique. The tribological tests were performed on a pin-on-disc tribometer at room temperature and it has been observed that friction and wear values reduce drastically while applying multilayer coatings. Later, artificial neural network (ANN) is employed to optimize the tribological properties of sputtered coatings.     

Tribological and electrical properties of nanocrystalline Cu films deposited by DC magnetron sputtering with varying temperature

Cu films were deposited on Si substrates by direct current (DC) magnetron sputtering at three different substrate temperatures such as room temperature (RT), 100 °C and 200 °C. Possible mechanisms for substrate temperature dependent microstructure evolution in Cu films are discussed in this paper. Enhanced mechanical properties such as high hardness, high elastic modulus, low friction coefficient and high wear resistance of the films were obtained at deposition temperature of 100 °C. However, high friction coefficient as well as high wear rate was measured in films deposited at room temperature and 200 °C.     

A power supply for magnetron sputtering systems

A design and electric circuits of the power supply for magnetron sputtering systems with a power of up to 5 kW are described. The power supply is intended for operation in direct-current (DC) or pulse modes with a pulse repetition rate of up to 100 kHz. The arc suppression system limits the energy delivered to the arc discharge at about 110 mJ in the DC mode and 9 mJ in the pulse mode, respectively. The possibilities of optimizing coatings by selecting working parameters of the power supply were demonstrated by the example of thin-film coatings of two types (Ag and Ga-doped ZnO thin films).     

基于磁控溅射制备铜基表面增强拉曼散射基底

为了提高拉曼光谱仪的探测灵敏度,设计了铜基表面增强拉曼散射(surface enhanced Raman scattering, SERS)薄膜基底。以Cu_(40)Ti_(60)合金为靶材,通过控制磁控溅射参数获得了一系列铜钛合金薄膜,采用脱合金法进一步获得了不同结构的铜基薄膜,系统地研究了不同溅射参数对铜基薄膜的SERS特性的影响,确定了制备SERS基底的最佳溅射参数。脱合金后所得铜膜具有多孔结构,能形成高强度局域电磁场,即SERS"热点"(hotspots),从而表现出优异的SERS增强性能。该基底制备成本低,重复性好,能用于灵敏检测且SERS增强因子可达1.8×10~7,具有较好的应用前景。     

Tribological and electrochemical performances of Cr/CrN and Cr/CrN/CrAlN multilayer coatings deposited by RF magnetron sputtering

CrN/CrAlN and Cr/CrN/CrAlN multilayers were grown with dual RF magnetron sputtering. The application of these multilayers will be wood machining of green wood. That is why ball-on-disc and electrochemical tests in NaCl aqueous solution were realized to elucidate the tribological and corrosion behavior of these coatings as they will be exposed to wear and corrosion during wood machining process. The samples/alumina and samples/WC coupling showed different wear mechanisms. The 300 nm thick Cr/CrN/CrAlN multilayer demonstrated the best tribological behavior and corrosion resistance. The influence of growth defects on corrosion resistance has been shown.     

2m大口径RB-SiC反射镜的磁控溅射改性

为了消除RB-SiC反射镜直接抛光后表面存在的微观缺陷,降低抛光后表面的粗糙度,提高表面质量,针对大口径SiC的特性,选择Si作为改性材料,利用磁控溅射技术对2m量级RB-SiC基底进行了表面改性。在自主研发的Φ3.2m的磁控溅射镀膜机上进行基底镀膜,利用计算机控制光学成型法对SiC基底进行了抛光改性。实验结果表明,改性层厚度达到15μm;在直径2.04m范围内,膜层厚度均匀性优于±2.5%;表面粗糙度由直接抛光的5.64nm(RMS)降低到0.78nm。由此说明磁控溅射技术能够用于大口径RB-SiC基底的表面改性,并且改性后大口径RB-SiC的性能可以满足高质量光学系统的要求。     

Structural and mechanical properties of (Cr,Ni) N single and gradient layer coatings deposited on mild steel by magnetron sputtering

Ternary single and gradient layer (Cr, Ni) N thin films were deposited on the mild steel substrate by unbalanced magnetron sputtering technique in order to evaluate mechanical properties for machine tools and automotive applications. Microstructure, chemical composition, surface morphology and phase analysis were carried out using field emission scanning electron microscopy, energy dispersive X-ray spectroscopy, atomic force microscopy and X-ray diffraction, respectively. Both single and gradient layer of (Cr, Ni) N coatings show a significant increment in mechanical properties such as hardness, adhesion strength and surface roughness along with the reduction of friction coefficient. Mechanical tests revealed that the hardness of the gradient layer increased up to 3.1 times due to the formation of Cr₂N and Ni phase whereas single layer showed the least friction. Single layer CrNiN layer exhibited 27.2% less surface roughness (R_a) in comparison with gradient layer. High values of surface roughness, hardness, thickness and friction could be correlated with high film-to-substrate adhesion (L_c2) for the gradient layer.     

磁控溅射制备碳化硼薄膜的结构与成分分析

近年来国际上³He资源的短缺造成了基于³He的中子探测器高昂的成本,而以碳化硼薄膜作为中子转换层的硼基中子探测器逐渐成为了最有前景的替代方案。通过直流磁控溅射制备了Ti/B₄C多层膜,并使用透射电子显微镜（TEM）、飞行时间二次离子质谱（ToF-SIMS）、X射线光电子能谱（XPS）等手段对薄膜的结构与成分进行表征。结果表明：Ti层存在结晶情况;H、O、N元素为薄膜内部的主要杂质,且多分布于Ti层与B₄C-on-Ti过渡层中;更高的本底真空度能够降低碳化硼薄膜内的杂质含量,提高B含量占比;中子探测效率测试结果证明本底真空度的提高能够有效提高碳化硼中子转换层的效率。     

Fretting wear and fracture behaviors of Cr-doped and non-doped DLC films deposited on Ti–6al–4V alloy by unbalanced magnetron sputtering

Cr-doped and non-doped diamond-like carbon (DLC) films were deposited on a Ti–6Al–4V alloy substrate using an unbalanced magnetron sputtering (UBMS). Fretting wear behavior of the specimens was investigated using a ball-on-disk fretting tester. The fracture phenomenon of the DLC films was determined as the number of fretting cycles to reach a high value of the friction coefficient. The results showed that the Cr-doped and non-doped DLC films exhibited a lower friction coefficient and wear rate compared to that of the uncoated specimen. However, the Cr-doped DLC film fractured only in a few cycles, while the non-doped DLC film fractured after fretting cycles of about 200,000. A fracture mechanism of the Cr-doped and non-doped DLC films was reported in this study.     

Target cleaning for faster CrN/AlN coating growth in magnetron sputtering

Metallic sputtering may be used to clean the target surface in the course of coating application by reactive magnetron sputtering. The introduction of additional stages of metallic sputtering in reactive magnetron sputtering increases the growth rate of CrN/AlN coatings by around 23%, with little change in physicomechanical properties.     

Tribological behavior of TiN films depositid by reactive magnetron sputtering under low pressure

The effect of deposition conditions on the tribological behavior of titanium nitride thin films produced by reactive magnetron sputtering has been studied. Dependences of the hardness, the width of the friction track, the friction coefficient, and the volume wear of the TiN films on the N₂ reactive gas flow rate have been obtained. Conditions of deposition under which the coatings with the best tribological characteristics are formed have been determined.     

Anti-oxidant mechanism of TiAlN/SiN decorative films on borosilicate glass by magnetron sputtering

The black TiAlN decorative film was prepared on the borosilicate glass by the magnetron sputtering in equipment with multiple vacuum chambers. The transparent SiN protective layer was deposited on the surface of the TiAlN film to keep the black color invariant at the high temperature. The structure of the TiAlN/SiN film was characterized by scanning electron microscope (SEM), X-ray diffraction (XRD), and high-resolution transmission electron microscopy (HRTEM). The coating adhesion was measured by scratch tester. The TiAlN film has a columnar crystal structure with a thickness of 200 nm, and the top SiN layer is amorphous with a thickness of 100 nm. The coated borosilicate glass with the TiAlN/SiN films still retains the black color after oxidation at 600 °C in atmosphere. While the oxidation temperature elevates to 700 °C, the color of the TiAlN/SiN films begins to change. The top SiN layer plays a role as the barrier against oxygen diffusion into the inner TiAlN layer. The thin self-formed aluminum oxide layer was generated on the surface of the SiN layer and it contributes to the improvement of anti-oxidant property of the inner TiAlN layer. However, the thick self-formed aluminum oxide layer leads to the color change of the black TiAlN film. The thermal oxidation benefits the improvement of the adhesion for the TiAlN/SiN films with glass substrate.     

磁控溅射法制备的五氧化二钒薄膜光电特性

利用射频磁控溅射方法,选取溅射时间为15,25,30和45min,在蓝宝石衬底上沉积了V2O5薄膜。研究了其他实验参量不变,溅射时间不同对薄膜结构、薄膜厚度、表面形貌、电学及光学性能的影响。实验结果表明,制备出的薄膜为单一组分的V2O5薄膜,其在(001)面有明显的择优取向。随着溅身时间的增加,结晶性能逐渐变强,晶粒尺寸也逐渐变大,而表面粗糙度值会逐渐降低;在晶体结构完整的基础上,随着溅射时间的增加,相变温度和经历的温度范围会逐渐增加,电学突变性能会降低。测试了薄膜在中红外波段的高低温透过率,结果显示:当膜厚为350nm,波长为5μm时,薄膜的透过率从25℃时的81%变为300℃的7%,变化幅度可达74%;所有薄膜相变前后透过率的比值均为9~13,表现出了非常突出的光学开关特性。     

Microstructure of MmM(5)/Mg multi-layer hydrogen storage films prepared by magnetron sputtering

Multi-layer hydrogen storage thin films with Mg and MmNi3.5(CoAlMn)1.5 (here Mm denotes La-rich mischmetal) as alternative layers were prepared by direct current magnetron sputtering. Transmission electron microscopy investigation shows that the microstructure of the MmNi3.5(CoAlMn)1.5 and Mg layers are significantly different although their deposition conditions are the same. The MmNi3.5(CoAlMn)1.5 layer is composed of two regions: one is an amorphous region approximately 4 nm thick at the bottom of the layer and the other is a nanocrystalline region on top of the amorphous region. The Mg layer is also composed of two regions: one is a randomly orientated nanocrystalline region 50 nm thick at the bottom of the layer and the other is a columnar crystallite region on top of the nanocrystalline region. These Mg columnar crystallites have their [001] directions parallel to the growth direction and the average lateral size of these columnar crystallites is about 100 nm. A growth mechanism of the multi-layer thin films is discussed based on the experiment results.