奥氏体不锈钢渗氮&物理气相沉积复合改性层的组织及性能

通过辉光离子渗扩技术对316L奥氏体不锈钢进行了不同温度下的离子渗氮处理,之后采用物理气相沉积技术在渗氮层外表面制备一层CrN涂层,检测不同温度下离子渗氮+物理气相沉积复合涂层的结合力、硬度、耐磨性和耐蚀性,并对其显微组织和物相进行了观测与分析.结果表明:奥氏体不锈钢不同温度渗氮+物理气相沉积复合改性层的组织随渗氮温度的升高从S相(内层)+CrN涂层(外层)转变为不同程度硬质相析出层(内层)+CrN涂层(外层),不同类型的渗氮层与CrN涂层均有良好的结合力;不论是S相层还是硬质相析出层,经过PVD处理后均能在一定程度上提高渗层的表面硬度、耐磨性和耐蚀性,其中耐蚀性随着渗氮温度的升高逐渐变差,硬度和耐磨性随渗氮温度的升高而逐渐提升.     

摩托车发动机活塞环复合涂层的研究

PVD物理气相沉积工艺是表面处理技术研究与应用的方向,研究了摩托车发动机活塞环复合涂层.试验方案在CG125摩托车国产环镀铬基础上再涂TiN或CrN硬质膜,复合涂层采用阴极反应磁控溅射法,应用金相法、扫描电镜、X射线能谱微区成分分析等方法,检测了活塞环基础组织和机械性能,PVD复合涂层的组织结构,并进行快速磨损试验和台架试验.研究结果表明,摩托车发动机活塞环复合涂层具有耐磨性好、对缸体磨损量小、结合牢固、涂层没有剥落、性能可靠、满足使用要求,具有很好的应用前景.     

物理气相沉积在镁合金表面防护领域的研究现状

镁合金表面耐腐蚀性能、耐磨性能较差,物理气相沉积(PVD)镀膜技术是一种提高镁合金表面性能的有效方法。总结了PVD镀膜防腐蚀层和耐磨层的特性,分析了涂层耐腐蚀耐磨的机理和存在的不足。综述了镁合金表面PVD膜层的研究进展,阐述了物理气相沉积技术对镁合金的表面改性的应用现状,并对该技术在镁合金上的发展进行了概括,指出了目前PVD技术在镁合金表面防护领域的新前景,为今后PVD技术对镁合金表面防护的研究与发展提供了相关参考。     

基于PVD-TiN和TiSiN涂层的Al2O3/TiCN陶瓷刀具及其切削性能研究

采用物理气相沉积(Physical vapor deposition, PVD)工艺在Al₂O₃/TiCN陶瓷刀具表面分别沉积了TiN和TiSiN涂层。通过扫描电子显微镜(SEM)观察涂层微观结构, 采用显微硬度计和划痕仪分别表征涂层硬度和测量涂层与基体的结合强度。通过对涂层刀具进行连续干切削灰铸铁实验, 研究TiN和TiSiN涂层对刀具磨损特征的影响并探讨其磨损机理, 同时研究了涂层对工件加工表面质量的影响。结果表明: PVD涂层可显著提高Al₂O₃/TiCN陶瓷的刀具硬度。TiN涂层和TiSiN涂层可分别提高刀具表面硬度25%和65%, 从而增加刀具耐磨性。两种涂层刀具在连续切削灰铸铁实验中主要的失效机理均是挤压变形下的磨粒磨损, 其中TiN涂层刀具还伴随有粘结磨损; 刀具上的PVD-TiN和TiSiN涂层可以有效保护Al₂O₃/TiCN陶瓷刀具基体, 防止崩刃, 进而改善工件表面加工质量。     

不同表面处理工艺下H13钢的高温耐磨性能

首先对调质处理状态的H13钢进行了渗氮、物理气相沉积(PVD)镀膜、渗氮+PVD镀膜三种不同的表面处理,然后在UMT-3型摩擦磨损试验机上,对处理后的试样进行600℃的高温摩擦磨损试验,研究了不同工艺下H13钢的高温耐磨性能。结果表明:试样的磨损形式主要是粘着磨损+磨粒磨损,经表面处理后试样的表面硬度大幅度提高,摩擦系数大幅度降低;其中渗氮+PVD镀膜表面处理试样的高温耐磨性能最好。     

日本开发模具用复合涂覆技术

日本日立金属公司将PVD（物理气相沉积）离子镀与阴极真空喷镀结合,开发出冷冲模用表面处理技术——复合涂覆技术。该技术可使模具寿命比原来提高1倍以上。     

车用316L不锈钢表面NV复合涂层的结构和耐磨性能分析

为了提高车用316L不锈钢的表面质量,综合运用粉末渗钒以及盐浴渗氮工艺在其表面制备单渗钒、先渗钒后渗氮(N/V)以及先渗氮后渗钒(V/N)涂层,并通过SEM、EDS、XRD、硬度测试仪、摩擦试验机等分析了其微观组织结构和耐磨性能.结果 表明:相对单V涂层而言,N/V和V/N涂层(统称NV涂层)的表面更为光滑,主要包含NV(111)与α-Fe 2种物相组织.其中V/N涂层中N元素含量较高,涂层表面富集了大量的Fe.V/N涂层硬度(1 691 HV)高于N/V涂层硬度(1 546 HV),两者的硬度均比单V层的高,并且涂层硬度均远高于不锈钢基体的硬度.与其他涂层相比,V/N涂层具有更小的摩擦系数(0.26),可以快速形成稳定磨损状态,其摩擦系数变化曲线相对平缓.V/N涂层与基体形成紧密结合状态,其磨痕深度较低并避免了犁沟的产生.     

2002年全国工模具失效分析与改性技术交流会通知

20 0 2年全国工模具失效分析与改性技术交流会于 2 0 0 2年 10月中旬在北京举行。会议由中国机械工程学会失效分析分会主办 ,模具专业委员会组织 ,现在全国征集论文和信息资料。　　征集范围包括 :失效分析技术和方法 ,典型模具失效案例 (冷作模具 ,热作模具 ,压铸模具 ,塑料模具等 ) ,典型工具失效案例 (切削工具 ,五金工具 ,其他各种工具等 ) ,新型工模具钢 ,硬质合金 ,陶瓷材料的应用 ,表面改性新技术 ,工模具材料提高寿命的新工艺 ;工模具质量管理等。欢迎工模具生产和使用企业提出失效问题和参加会议。　　会议将邀请我国材料工程和工…     

物理气相沉积在耐腐蚀涂层中的应用

PVD(物理气相沉积)作为一种新型绿色的镀膜技术,由于涂层具备硬度高、耐磨性好、摩擦系数低、化学性能稳定、耐热耐氧化的特点,使其在机械、电子和光学行业得到广泛应用。近些年来随着PVD技术应用领域的不断扩展,对涂层的性能提出了更高要求,在保障力学性能的同时,如何提高涂层耐蚀性成为研究热点。概述了PVD技术应用于材料防腐的相关研究,综述了PVD涂层的成分、结构与耐蚀行为的关系,同时分别阐述了在PVD技术中提高涂层耐蚀性能的方法与机理。     

PVD Si涂层用于SiC陶瓷的表面改性研究

为了获得高质量的光学表面,采用RF磁控溅射法在RB SiC和SSiC陶瓷表面涂覆一层结构致密的PVD Si涂层.采用XRD、AFM和表面轮廓仪对抛光后的PVDSi涂层进行了表征,并在可见光波长范围内测量了涂层的反射率.结果表明,当RB SiC和SSiC陶瓷表面涂覆PVD Si涂层后,抛光后其表面缺陷明显减少,表面粗糙度的均方根RMS可达埃级,反射率提升幅度明显.并简单分析了反射率提高的主要原因.     

激光熔覆-活化屏等离子体复合处理层耐磨性能研究

为了研究激光熔覆层性能对活化屏等离子体氮化处理层耐磨性能的影响,采用两种铁基合金粉末(Fe90和Fe314)在45钢基体表面进行激光熔覆,然后进行等离子体氮化复合处理,测试涂层干摩擦条件下的磨损性能。研究结果表明:复合处理后,Fe90激光熔覆层的硬度由750HV提高到1350HV,Fe314激光熔覆层的硬度由540HV提高到927HV;在相同载荷(30N)下,Fe90复合处理层的耐磨性提高到1.2倍,而Fe314复合处理的耐磨性降低为原来的42%;复合处理耐磨性能提高的关键在于激光熔覆层与氮化层的合理搭配,熔覆层能够提供足够的支撑。     

PVD‐Schutzschichten für Werkzeuge des Präzisionsblankpressens

PVD protective coatings for precision molding tools Precision glass molding (PGM) is a replicative hot forming process for the production of complex optical components, such as aspherical lenses for digital and mobile phone cameras or optical elements for laser systems. The efficiency and thus also the profitability of the PGM depend on the unit price per pressed component, which correlates primarily with the service lifetime of the pressing tools. To increase tool lifetime, the tool surfaces are coated with protective coatings based on precious metals or carbon using physical vapour deposition (PVD). The PVD coating technology enables the deposition of thin coatings, which also follow more complex surface geometries and achieve a high surface quality. PVD coatings are also commonly used to protect tools from wear and corrosion. This paper presents two chromium‐based nitride hard coatings produced by an industrial PVD unit and investigated for their applicability for PGM. Two different coating architectures were implemented, on the one hand a single coating chromium aluminium nitride (Cr,Al)N coating and on the other hand a nanolaminar CrN/AlN coating with alternating layers of chromium nitride and aluminium nitride. The latter is a coating consisting of hundreds of nano‐layers, only a few nanometers thick. Both coatings, (Cr,Al)N and CrN/AlN, each have a thickness of s ～ 300 nm in order to follow the tool contour as closely as possible. The properties of the coating systems, which are of particular relevance for PGM, are considered. These include on the one hand the adhesion of glass, the roughness and topography of the surface and the adhesion between the coating and the tool material. In addition, the barrier effect of the coatings against diffusion of oxygen was investigated. In order to reproduce the thermal boundary conditions of the PGM, thermocyclic aging tests are performed and their influence on the different properties is described.     

IMPROVEMENT OF CUTTING TOOLS BY TiN PVD HARD COATING

A review of recent results obtained in the field of cutting tools improved with a TiN physical vapor deposition (PVD) ion-plated hard coating is presented. Optimization of the tool material, tool surface morphology and interface problems between the TiN coating and the tool surface are discussed in view of their importance in optimum performance tests and the resulting workplace surface quality. The high effectiveness of the TiN PVD coating is demonstrated by selected data from our own data bank and from other sources on six groups of cutting tools, made of high-speed steels (HSS), powder metallurgical high-speed steels (PM-HSS) and of WC based hard metals. We also describe recently introduced, novel hard coatings (TiCN and TiAIN) for cutting tools, and new applications of cutting tools, improved by PVD hard coatings.     

Deposition of PVD Coatings on different geometries and local characterization for reliable properties

Although the characteristics of PVD coatings in research and development papers are very promising, in the field of tribology the industrial application of these coating types is restricted to special market segments up to now: the deposition of hard coatings is state of the art on tools, whereas PVD coated machine components are quite rare. This is caused by the coatings profile of properties, the various surroundings and the demands for application reliability. The last aspect is the main topic of this contribution. Reliability is especially important for machine components, because tools may fail after relative short life time compared to machine parts. Besides this tools and the corresponding production equipment are designed for fast tool replacement in contrast to other machines, which should work without standstill and with a minimum of maintenance. Characteristics of coated systems must be guaranteed in practice theory and laboratory experiments have to show what is possible. On the one hand reproduction of the deposition process must be guaranteed to enter application fields with high demands for reliability, on the other hand characterization of coated systems must be standardized with admissible deviations for communication between coaters and users. These aspects are important for decisions concerning the use of coating substrate systems in tribology besides the topics of technical function. The present investigation shows main reasons for deviations in results of PVD coatings.     

PVD – Eine Erfolgsgeschichte mit Zukunft

PVD – A success story with a future PVD coatings in the range of a few nanometers up to some microns have become state of the art in engineering technology. PVD coatings can be found anywhere in our everday lives. They are used in data storage mediums such as CDs or DVDs. Car or architectural glasses are improved by thermal insulation coatings. A diffusion barrier is achieved via PVD coatings at food packaging. For decorative aspects sham jewelery and accessoires are coated as well as fittings. In the last three decades PVD coatings have been established in a variety of technical applications acquiring wear protection and/or friction reduction. First, coatings for tools have been developed, later on for components as well. So, in the past lots of experiences have been made not only in coating development, but likewise in methodical product design. By contrast, the surface has not yet been regarded as construction element. Here the knowledge is just at the beginning. The achieved performance of coated components can be improved drastically if the tribological system consisting of coating, substrate and intermediate material is designed for one single application with regard to the macro‐ and micro geometry. An exemplary application derived from the collaborative research center (SFB 442) “Environmentally friendly tribosystems” at the RWTH Aachen university is discussed. Results of fundamental research and their way into industrial applications are presented. The research development is reflected with regard to the development of the industrial PVD market. Regarding a process chain for the exemplary application the development method of surface technology is explained beginning with the production up to field testing of a new product.     

Structure, mechanical properties and corrosion resistance of nanocomposite coatings deposited by PVD technology onto the X6CrNiMoTi17-12-2 and X40CrMoV5-1 steel substrates

This article presents the research results on the structure and mechanical properties of nanocomposite coatings deposited by PVD methods on the X6CrNiMoTi17-12-2 austenitic steel and X40CrMoV5-1 hot work tool steel substrates. The tests were carried out on TiAlSiN, CrAlSiN and AlTiCrN coatings. It was found that the structure of the PVD coatings consisted of fine crystallites, while their average size fitted within the range 11–25 nm, depending on the coating type. The coatings demonstrated columnar structure and dense cross-sectional morphology as well as good adhesion to the substrate, the latter not only being the effect of adhesion but also by the transition zone between the coating and the substrate, developed as a result of diffusion and high-energy ion action that caused mixing of the elements in the interface zone. The critical load L _C2 lies within the range 27–54 N, depending on the coating and substrate type. The coatings demonstrate a high hardness (~40 GPa) and corrosion resistance.     

Erosions‐Korrosions‐Untersuchungen an gradierten Multilayer‐Chromkarbidschichten

Erosion corrosion of graded chromium carbide coatings in multi layer structure So far PVD‐ and PECVD‐Layers have proved their value as wear protection mainly on cutting tools for machining. Depending on the composition of the layers not only a reduction in wear but also a reduction in friction is possible, e.g. by integration of hydrogen containing carbon. Furthermore such carbon containing layers use to be electrochemically inert. Thus they don’t corrode in aqueous media. Because they do also have a very dense structure, an application as corrosion protection seems to be promising. For the intended investigations under service‐like erosiv‐corrosiv loading a new testing rig was developed and constructed. The erosiv‐corrosiv loading was achieved by exposure of coated specimen to a flowing medium, that contains abrasive corund‐particles. Thus the erosion‐corrosion‐behaviour of new graded Multilayer‐Chromiumcarbide‐Coatings should be investigated. The aim was to identify the mechanisms of deterioration to promote a further developement of these layers. In addition the potential of PVD/PECVD‐coated low‐alloy steel to be in‐service under such conditions should be evaluated. For comparison an up‐to‐date industrial DLC‐coating and a high‐alloy duplex‐steel were also investigated. As a result of the conducted investigations an application of PVD‐/PECVD‐coated low‐alloy steel under erosive‐corrosive conditions with impingement wear could not yet be recommended. However the graded Multilayer‐Chromiumcarbide‐Coatings have the potential for a good erosion‐corrosion‐protection, if erosion promoting flaws are avoided. Because hard PVD‐ and PECVD‐coatings are relative brittle, a loading with hard particles, which hit the surface under a high angle, is very tough. Hence the question is, if the investigated layers possibly have a better wear behaviour under more abrasive loading in a more tangential flowing medium, which is also typical for in‐service‐conditions. This is intended to be investigated in future tests.     

Influence of deep cryogenic treatment of high speed steel substrate on TiAlN coating properties

Deep cryogenic treatment in combination with classic heat treatment shows a significant improvement in wear resistance of high speed steel tools. The aim of this research was to investigate how the microstructure of the substrate tool steel material, which was altered by deep cryogenic treatment and plasma nitriding, influences the properties of TiAlN coating. The microstructure, topography and composition of the TiAlN coating were investigated using field‐emission scanning electron microscope, atomic force microscopy, XRD, and glow discharge optical emission spectroscopy. The coating adhesion was measured using the scratch test. The sliding wear resistance and the force required to break the coating were determined with the ball‐on‐flat method. Resistance to microabrasion was measured by free ball abrasion test. The results show that deep cryogenic treatment combined with plasma nitriding influence the adhesion of the TiAlN coating to the high speed steel substrate. Wear resistance tests show better wear resistance of deep cryogenic treated samples in comparison with conventionally heat treated ones.     

Schichtentwicklung für die schmiermittelfreie Umformung von hochfesten Aluminiumwerkstoffen

Development and evaluation of coatings for lubricant free forming of high strength aluminium Many applications in light weight construction require massive formed high strength aluminium parts. For economical and ecological reasons the use of lubricants for massive forming has to be avoided. Both, lubricant free forming and processing of high strength materials are big challenges that can be realized by using coated tools with functional surfaces that show high wear resistance, low friction and low adhesion to aluminium [1–7]. For goal‐oriented surface engineering different coating technologies, such as Physical Vapour Deposition (PVD) and Chemical Vapour Deposition (CVD) have been used for the preparation of specimens. The coating properties are evaluated by mechanical tests and numeric simulation to investigate the massive forming processes and the coating‐substrate‐behaviour. On the base of TiCN‐, TiC‐TiN‐ and DLC‐coatings on steel it is shown how relevant coating properties like Young’s Modulus, crack behaviour and hardness can be analyzed with regard to small coating thicknesses. In order to scale up the results to industrial conditions, finally the simulation is correlated to real deforming.     

Structure and mechanical properties of gradient coatings deposited by PVD technology onto the X40CrMoV5-1 steel substrate

This paper presents the research results on the structure and mechanical properties of gradient coatings deposited by PVD methods on the X40CrMoV5-1 steel substrate. The tests were carried out on TiAlN, TiCN and AlSiCrN coatings. It was found that the structure of the PVD coatings consisted of fine crystallites, while their average size fitted within the range of 15–50 nm, depending on the coating type. The coatings demonstrated columnar structure as well as good adherence to the substrate, the latter not only being the effect of adhesion but also by the transition zone between the coating and the substrate, developed as a result of diffusion and high-energy ion action that caused mixing of the elements in the interface zone. The critical load L _C2 lies within the range of 46–59 N, depending on the coating type. The TiAlN coatings demonstrate the highest hardness and abrasive wear resistance. The good properties of the PVD gradient coatings make them suitable in various engineering and industrial applications.