手表装饰用类金刚石薄膜的性能研究

采用多弧离子镀与离子束辅助磁控溅射复合工艺在316L不锈钢上制备了手表装饰用类金刚石(DLC)梯度薄膜(Cr–WC–DLC),研究了薄膜的外观、组成、硬度、耐蚀性、耐磨性、防刮花性能及结合力。结果表明,该方法制得的DLC梯度薄膜呈亮黑色且均匀一致,硬度达28GPa,sp~3结构含量约53%,具有优良的结合强度和耐蚀、耐磨、防刮花性能,是理想的手表用装饰性膜层。     

类金刚石膜的性能、制备及其应用

类金刚石膜是无定形碳中含sp3键的亚稳态结构.由于它的组成、光学透过率、硬度、折射率和在化学腐蚀剂中的惰性以及抗摩擦性能十分相似于金刚石,其应用领域不断被拓宽,因此对类金刚石的研究也日益成为热点.本文介绍了类金刚石的性能、制备类金刚石膜的物理气相沉积和化学气相沉积方法,概括了类金刚石膜在机械、电磁学、光学、医学以及其它领域的应用,最后指出了类金刚石膜的研究现状及其发展趋势.     

汽车玻璃超亲水涂膜的制备

合成了硅溶胶/丙烯酸羟丙酯杂化溶胶,采用紫外固化工艺,制备了超亲水汽车玻璃涂层.膜层的水接触角小于5°,铅笔硬度达到5H.讨论了硅溶胶浓度、丙烯酸羟丙酯相对含量等对薄膜亲水性、硬度、外观的影响.通过X-射线光电子能谱仪(XPS)、红外光谱(FT-IR)、扫描电子显微镜(SEM)等手段表征了膜层的组成和微观结构,分析了膜层的组成和微观结构对其性能的影响.     

TiO_2薄膜对金刚石磨料的抗氧化性能及磨削性能的影响

为解决传统电镀工艺在进行金刚石磨料表面改性时所产生的能耗及环境污染问题,采用溶胶-凝胶工艺在金刚石表面涂覆了一层致密的TiO2薄膜.通过扫描电镜、能谱、红外光谱、Raman光谱和综合热分析等手段对涂膜后的金刚石磨料表面形貌、结构和性能进行表征.结果显示:表面涂覆TiO2薄膜的金刚石磨料在空气中开始氧化并发牛质量损失的温度为700℃,较未涂膜的金刚石磨料的起始氧化温度提高150℃.用涂TiO2膜金刚石磨料制备的陶瓷结合剂金刚石砂轮,其硬度较未涂膜磨料制备的砂轮提高13%,对硬质合金的摩耗比提高2.2倍.     

丙烯酸阳极电泳涂料制备及电泳涂装工艺

制备了一种新型水溶性丙烯酸阳极电泳涂料,研究了45#碳钢磷化膜、电泳涂装工艺对漆膜性能的影响,结果表明:涂料黏稠透明,易溶于水,漆膜质量好,外观平整光亮。磷化膜能增加漆膜的附着力、厚度和硬度,最佳中温磷化时间为6 m in。电泳涂装最佳工艺参数为:电泳电压30 V,电泳温度25℃,电泳时间90 s,极间距为4 cm。     

镀锌层三价铬黑色钝化膜的优选配方

东风汽车有限公司工艺研究所研究人员采用正交试验对影响镀锌层三价铬钝化膜性能的各因素进行了优化,对钝化膜的耐蚀性、附着力和外观     

DLC层厚度对CNx/DLC多层膜结构及摩擦学性能的影响

采用直流磁控溅射法在硅基底上交替沉积类金刚石碳(DLC)和氮化碳(CNx)薄膜,制备了不同DLC层厚度的CNx/DLC纳米多层膜。使用X射线衍射、场发射扫描电子显微镜、X射线光电子谱、Raman光谱等测试手段表征了薄膜的微观组织形貌、化学成分和原子价键结构等。采用原位纳米压入技术、涂层附着力划痕仪、球盘式摩擦磨损试验机对薄膜的力学和摩擦学性能进行了测试。结果表明:所制备的CNx/DLC多层膜均为微晶或非晶结构,组织致密。随着DLC层厚度的减小,多层膜内sp3杂化键的含量先升高后下降,压应力由135 MPa增至538 MPa,结合力先上升后降低,而磨损率则呈相反变化趋势。多层膜在大气和真空中的摩擦因数约为0.17和0.15,DLC层厚度的影响很小。DLC层厚度为4.5 nm的多层膜的性能最佳,硬度可达44.1 GPa,最低磨损率为3.2×10-18m3/(N·m)。     

润滑耐磨涂层在电子设备表面的性能比较

电子设备在装配与使用过程中,经常出现磨损情况。为此,采用润滑耐磨涂料进行涂覆层实验,对涂层附着力、硬度、表面形貌、耐磨性及耐蚀性进行测试,并进行了比较。结果表明,润滑耐磨涂料制备的膜层各项性能最优,适合于电子设备表面润滑耐磨的工艺要求。     

锌-铁合金镀层三价铬黑色钝化工艺的研究

采用正交试验法对锌一铁合金镀层三价铬黑色钝化工艺进行优化,并研究了工艺参数对钝化膜外观和耐蚀性等影响.根据实验结果优选锌一铁合金镀层三价铬黑色钝化工艺.该工艺含有氯化铬、硝酸、硼砂、镍盐和磷酸根,采用有机羧酸作配位荆.该工艺能获得外观均匀黑亮、附着力良好的膜层,中性盐雾试验出白锈时间大于96 h.     

镀锌层三价铬黑色钝化工艺与性能研究

采用正交试验法对镀锌层三价铬黑色钝化工艺组分进行优化,研究了工艺参数对钝化膜外观和耐蚀性的影响。根据实验结果优选出镀锌层三价铬黑色钝化工艺,该工艺含有三价铬盐、硝酸盐、钴镍盐和磷酸根,采用有机羧酸作配位剂。此工艺能够获得外观均匀黑亮、附着力良好的膜层,中性盐雾试验出白锈时间大于120h。     

Relationship between interlayer hardness and adhesion and pin-on-disc behaviour for fast atom beam source diamond-like-carbon films

The effect of interlayers of Ti, and Ti(C,N) on the adhesion, hardness and friction coefficient of DLC films deposited using a Fast Atom Beam (FAB) source has been studied. Values obtained for DLC films on top of interlayers were compared with those of DLC films directly deposited on Co-Cr substrates by both the FAB source and RF CVD techniques. The scratch test adhesion of such coatings can be classified in the following ascending order: DLC/Ti, DLC/no interlayer, DLC/Ti(C,N). The surface composite hardness is greatly improved by a Ti(C,N) interlayer. However, DLC films deposited on Ti(C,N) failed during the pin-of-disc test whilst those on Ti and without an interlayer exhibited low friction coefficients and excellent wear performance. An explanation is developed in order to explain the causes of film failure during the pin-on-disc test. For a given interlayer hardness, an adhesion threshold is required to survive the pin-on-disc test. The higher the hardness, the greater the required adhesion threshold, as interfacial shear stresses induced by the pin-on-disc are greater for hard surfaces, due to the smaller contact area.     

Tribological properties of graded diamond-like carbon films on Ti ion-implanted aluminum substrate

Titanium ions are implanted into the aluminum substrate prior to deposition of the Ti interlayer and DLC graded film produced by magnetron sputtering in order to enhance the structural continuity between the soft substrate and graded DLC film. The Ti-implanted substrate not only strengthens loading support but also improves adhesion with the overlying film. The total thickness of the functionally graded film on the Al substrate reaches over 10 μm and it has a hardness value of ~ 11 GPa. The graphitic network in DLC film helps to reduce the friction coefficient while the graded design disperses the stress during wear and loading.     

Thermal annealing behaviour of alloyed DLC films on steel: Determination and modelling of mechanical properties

A shortcoming of diamond-like carbon (DLC) films is the poor stability of their microstructure and properties at elevated temperatures. In this study, the effect of annealing on the stability of DLC films alloyed with silicon and deposited on steel is investigated. A comprehensive study of the mechanical properties is carried out by a novel method combining normal indentations with micro- and macroindentors assisted by finite element calculations of the indentation. The mechanical properties of the layers are correlated to structural changes in the film and to interface reactions.While it has become a common practice to determine hardness and the Young's modulus of thin films by nanoindentation and to calculate residual stresses from the bending of the film/substrate system, evaluation of the interface toughness, which is a measure of adhesion, and of the film rupture strength is less straightforward. Here, Hertzian-type ring cracks are generated in the film by nanoindentation of the film/substrate system with spherical diamond tips. From the critical load for crack generation the film rupture strength is deduced using finite element calculations. Similarly, Rockwell C hardness tests in combination with calculations are performed to measure the interface toughness.Applying these methods to DLC films on steel, it has been found that the Young's modulus decreases with increasing silicon content and the residual stress drops below 1 GPa. The rupture strength approaches its theoretical limit of E/10. Annealing at 500 °C reduces the adhesion energy significantly. The variation of mechanical properties can be attributed to structural changes in the film as investigated by Raman spectroscopy.     

Adhesion Reduction of Diamond-Like Carbon Films Based on Different Contact Geometries by Using an AFM

The effect of reducing adhesion force by coating with a metal-containing diamond-like carbon (DLC) film has been studied by recording force–displacement curves with an atomic force microscope. A flat tip, a spherical tip, and some sharp tips were applied to mimic the different contact geometries. The results show that both under ambient conditions and in dry nitrogen, the DLC film can effectively reduce the adhesion force for different contact geometries. The reduction of the adhesion force was attributed to the decrease of the surface free energy and the increase of the contact angle for water. The reduction ratio of adhesion is closely related to contact geometry, the roughness of DLC film, material characteristics paired with DLC film and the environment. These factors are mutually coupled to determine the final reduction ratio. Under both conditions, the DLC film also plays a role in reducing the wear and tear when measuring the adhesion forces.     

Influence of plasma nitriding treatment on the adhesion of DLC films deposited on AISI 4140 steel by PVD magnetron sputtering

Duplex surface treatments composed of diamond like carbon (DLC) coating followed by plasma nitriding have drawn attention for a while. In this study, AISI 4140 steel substrates were plasma nitrided at different treatment temperatures and times. Then, DLC films were deposited on both untreated and plasma nitrided samples using PVD magnetron sputtering. The effect of different plasma nitriding temperatures and times on the structural, mechanical and adhesion properties of DLC coatings was investigated by XRD, SEM, microhardness tester and scratch tester, respectively. It was found that surface hardness, intrinsic stresses, layer thickness values and phase distribution in modified layers and DLC coating were the main factors on adhesion properties of duplex coating system. The surface hardness and residual stress values of AISI 4140 steel substrates significantly increased with both DLC coating and duplex surface treatment (plasma nitriding + DLC coating). Increasing plasma nitriding temperature and time also increased the diffusion depth and the thickness of modified layers. Hard surface layers led to a significant improvement on load bearing capacity of the substrate material. However, it was also determined that the process parameters, which provided lower intrinsic stresses, improved the adhesion properties of the duplex coating system.     

类金刚石薄膜在人工关节摩擦副表面改性进展

类金刚石（DLC）薄膜由于其优异的减摩耐磨性以及良好的生物相容性被引入到人工关节材质中。该文综述了DLC薄膜在人工关节摩擦副表面改性的研究现状,包括DLC薄膜的分类和制备方法。尽管该薄膜已被研究数十年,但在人体复杂的生理力学环境中高负荷摩擦腐蚀等综合作用下,仍存在高内应力导致结合力不足,从而限制其在人工关节领域的应用。该文介绍了降低DLC薄膜内应力提高膜基结合力的方法和DLC薄膜生物相容性的研究进展。最后,对不同DLC薄膜人工关节摩擦副的研究进展进行了阐述。根据该综述,提出厚的无氢DLC涂层（高sp3含量）,且在两个滑动表面上均有DLC薄膜的人工关节副具有优异的耐磨性,对于承重植入体应用至关重要。     

Microstructure and mechanical properties of Mo/DLC nanocomposite films

Mo-doped diamond-like carbon (Mo/DLC) films were deposited on stainless steel and Si wafer substrates via unbalanced magnetron sputtering of molybdenum combined with inductively coupled radio frequency (RF) plasma chemical vapor deposition of CH₄/Ar. The effects of Mo doping and sputtering current on the microstructure and mechanical properties of the as-deposited films were investigated by means of X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), transmission electron microscopy (TEM), Raman spectroscopy, atomic force microscopy (AFM), and nano-indentation. It was found that Mo doping led to increase in the content of sp² carbon, and hence decreased the hardness and elastic modulus of Mo/DLC films as compared with that of DLC films. The content of Mo in the films increased with the increasing sputtering current, and most of Mo reacted with C atoms to form MoC nanocrystallites at a higher sputtering current. Moreover, the Mo-doped DLC films had greatly decreased internal stress and increased adhesion to the substrate than the DLC film, which could be closely related to the unique nanocomposite structure of the Mo-doped films. Namely, the Mo/DLC film was composed of MoC nanoparticles embedded in the cross-linked amorphous carbon matrix, and such a kind of nanostructure was beneficial to retaining the loss of hardness and elastic modulus.     

Effect of increasing hardness on Si-containing diamond-like carbon film during tribo-test

In this study, silicon-DLC film has been especially treated by plasma-enhanced chemical vapor deposition (PECVD) process at 500 °C in the same chamber without compound-layer for enhancement of hardness and adhesion. The effects of different levels of silicon content on the silicon-containing DLC films were tested in air condition at room temperature with relative humidity using a ball-on-disk tribometer. After the wear test, Raman spectrum analysis on the tested surface of silicon DLC showed the changed structure on the surface. Especially, it has shown the increasing hardness value in proportional to increase TMS gas rate after wear test. At the same time, it was shown that I_D/I_G values increased higher G-peak values and positions on wear track of silicon-containing DLC surfaces. Therefore, the structure of the coated DLC surface changed between the wear-tested surface and the original surface. High silicon content DLC showed increased I_G value with suddenly increased I_D/I_G value after the wear test.     

The effect of annealing on mechanical and tribological properties of diamond-like carbon multilayer films

The diamond-like carbon (DLC) multilayer films have been deposited by plasma CVD deposition onSi wafer substrate. The deposited films have then been post-annealed in vacuum at 250 °C for 2 h. Changes in internal stress, hardness, critical load, friction coefficient and wear have been investigated toassess the influence of annealing on mechanical and tribological properties of DLC multilayer films. At the same time, DLC single layerfilms are also deposited and annealed in the same method for a comparison.The results show that there is 28–33% decrease in internal stress and 10–13% decrease in hardness of theDLC single layer films after the anneal treatment. However, for the DLC multilayer films, there is 41–43% decreasein internal stress and less than 2% decrease in hardness. In addition, the annealed DLC multilayer filmhas the same friction and wear properties as that un-annealed film. This result indicates that the anneal treatment isan effective method for the DLC multilayer films to reduce the internal stress and to increase the critical load.The by-effect of the annealing, decrease of hardness and wear resistance of the multilayer film, can be restrictedby the multilayer structure.     

Effects of thermal annealing and Si incorporation on bonding structure and fracture properties of diamond-like carbon films

The effects of thermal annealing and Si incorporation on the structure and properties of diamond-like carbon (DLC) films were investigated. As-deposited DLC film (DLC) and Si incorporated DLC film (Si-DLC), both with and without thermal annealing, were analyzed for bonding structure, residual stress, film thickness, elastic modulus and fracture properties using Raman spectroscopy, wafer curvature, nanoindentation, four-point bend fracture testing, and X-ray photoelectron spectroscopy (XPS). Raman spectroscopy clearly showed that thermal annealing of DLC films promotes more sp² bonding character, whereas Si incorporation into the films promotes more sp³ bonding character. Interfacial fracture energies, film hardness and elastic modulus, and residual film stress were all found to vary strongly with the degree of sp³ bonding in the DLC film. These changes in mechanical properties are rationalized in terms of the degree of three dimensional inter-links within the atomic bond network.