共查询到20条相似文献,搜索用时 31 毫秒
1.
T. Kups A. Knote H.‐G. Krüger H.‐V. Winkler H. Kern L. Spieß 《Materialwissenschaft und Werkstofftechnik》2009,40(12):894-900
Formation and characterization of metal‐ceramic coatings The influence of the formation process and used materials of metal‐ceramic coatings on the structural properties of the deposited layers were investigated and optimized to increase the mechanical properties. There the deposition of the metal‐ceramic‐layers occurred by a combination of electrophoretic and galvanic deposition with siloxane as bonding compound. Layers with a high ceramic content were successfully created. As ceramic components commercial silicon carbide and silicon nitride were used. Nickel and Copper respectively were applied as metal component to fill the porous ceramic structure with the aim to increase the strength of the layers, where nevertheless a pre nickel‐plating or pre cupper plating of the steel substrate X6Cr17 before ceramic component deposition had to be done to increase the adhesion of the layers. The layer characterization was made by optical microscopy and scanning and transmission electron microscopy, where especially the bonding of the single particles by the siloxane was in evidence. 相似文献
2.
Easy to clean surfaces – special applications Easy to clean surfaces can be made by wet‐chemical coating with subsequent heat‐treatment. Organically modified metal oxide films form the base reinforced by nano composite structures. The hydro‐ and oleophobic effect is obtained by perfluorinated organic molecule chains in the nano composite sol‐gel coatings. Application specific materials can be synthesized by the proper choice of suitable starting compounds and process parameters. The resulting coatings consist of a three‐dimensional cross‐linked inorganic part (such as a silica network) combined with an organic part. The organic material acts either as a surface modifier (example: alkyl, phenyl) or as crosslinker (example: acrylic, epoxy). The properties of such coating systems can be adjusted to obtain a wide range of glass‐ceramic or polymer‐like properties. The incorporation of nanoparticles into these materials significantly enhances the abrasion and the scratch resistance. Such coatings mainly on metal parts are used in diagnostics, analytical chemistry and medical technology. 相似文献
3.
M. Dietrich V. Verlotski R. Vaßen D. Stver 《Materialwissenschaft und Werkstofftechnik》2001,32(8):669-672
A new concept of thermal barrier coating (TBC) system is presented, based on a metal‐glass composite (MGC). Coatings of metal‐glass composite can be deposited by vacuum plasma spraying and slip casting with a subsequent sinter step. In this TBC system the thermal expansion coefficient depends on the metal‐glass ratio. It is chosen in such a way that the thermal expansion coefficient of the composite is close to the one of the substrate. This leads to reduced thermal stresses and hence improved thermal cycling life times. Because of the low thermal mismatch, coatings of more than 600 μm thickness can be realized. Another advantage of the gas tight composite coatings is their ability to protect the bondcoat from severe oxidation. Correspondingly, long life times have been found for these TBCs in oxidation tests. Also good results were found during thermal cycling tests. Furthermore some aspects of the microstructure evolution of the composite during heat treatment are described. 相似文献
4.
Cao Guan Zhiyuan Zeng Xianglin Li Xiehong Cao Yu Fan Xinhui Xia Guoxiang Pan Hua Zhang Hong Jin Fan 《Small (Weinheim an der Bergstrasse, Germany)》2014,10(2):300-307
Nanostructured carbon is widely used in energy storage devices (e.g., Li‐ion and Li‐air batteries and supercapacitors). A new method is developed for the generation of carbon nanoflakes on various metal oxide nanostructures by combining atomic layer deposition (ALD) and glucose carbonization. Various metal oxide@nanoflake carbon (MO@f‐C) core‐branch nanostructures are obtained. For the mechanism, it is proposed that the ALD Al2O3 and glucose form a composite layer. Upon thermal annealing, the composite layer becomes fragmented and moves outward, accompanied by carbon deposition on the alumina skeleton. When tested as electrochemical supercapacitor electrode, the hierarchical MO@f‐C nanostructures exhibit better properties compared with the pristine metal oxides or the carbon coating without ALD. The enhancement can be ascribed to increased specific surface areas and electric conductivity due to the carbon flake coating. This peculiar carbon coating method with the unique hierarchical nanostructure may provide a new insight into the preparation of ‘oxides + carbon’ hybrid electrode materials for energy storage applications. 相似文献
5.
Exploring the Nickel–Graphene Nanocomposite Coatings for Superior Corrosion Resistance: Manipulating the Effect of Deposition Current Density on its Morphology,Mechanical Properties,and Erosion‐Corrosion Performance
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Ghulam Yasin Muhammad Arif Muhammad Shakeel Yuchao Dun Yu Zuo Waheed Qamar Khan Yuming Tang Ajmal Khan Muhammad Nadeem 《Advanced Engineering Materials》2018,20(7)
6.
Yong‐Hui Song Kai‐Jin Wu Tian‐Wen Zhang Lei‐Lei Lu Yong Guan Fei Zhou Xiu‐Xia Wang Yi‐Chen Yin Yi‐Hong Tan Feng Li Te Tian Yong Ni Hong‐Bin Yao Shu‐Hong Yu 《Advanced materials (Deerfield Beach, Fla.)》2019,31(51)
The commercial ceramic nanoparticle coated microporous polyolefin separators used in lithium batteries are still vulnerable under external impact, which may cause short circuits and consequently severe safety threats, because the protective ceramic nanoparticle coating layers on the separators are intrinsically brittle. Here, a nacre‐inspired coating on the separator to improve the impact tolerance of lithium batteries is reported. Instead of a random structured ceramic nanoparticle layer, ion‐conductive porous multilayers consisting of highly oriented aragonite platelets are coated on the separator. The nacre‐inspired coating can sustain external impact by turning the violent localized stress into lower and more uniform stress due to the platelet sliding. A lithium‐metal pouch cell using the aragonite platelet coated separator exhibits good cycling stability under external shock, which is in sharp contrast to the fast short circuit of a lithium‐metal pouch cell using a commercial ceramic nanoparticle coated separator. 相似文献
7.
Nitridische und oxinitridische HPPMS‐Beschichtungen für den Einsatz in der Kunststoffverarbeitung (Teil 1)
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Prof. Dr. Kirsten Bobzin Prof. Dr. Guido Grundmeier Tobias Brögelmann Dr. Teresa de los Arcos Martin Wiesing Nathan C. Kruppe 《真空研究与实践》2016,28(6):28-33
Nitride and oxy‐nitride HPPMS coatings for the application in the plastics processing (Part 1) In plastics processing adhesive and abrasive wear are some of the main damage mechanisms. For the wear protection and in order to increase the tool life time as well as to improve the quality of the plastic products, binary or ternary chrome‐based coatings like CrN and (Cr,Al)N deposited by physical vapor deposition (PVD) are used. As the chemical composition of the coating has a significant impact on the surface oxide layer formed after deposition and therefore on the wetting behavior of the plastic melt on the tool surface, the aim on this work was to synthesize different coatings from the system Cr‐Al‐O‐N. Therefore, a nitride coating (Cr,Al)N and two quaternary oxy‐nitride coatings (Cr,Al)ON were deposited by using a dcMS/HPPMS (direct current magnetron sputtering/high power pulse magnetron sputtering) hybrid process by varying the oxygen flux. This articles emphasis is on explaining the influence of varying the oxygen flux during the coating process on the coating properties as well as the composite properties towards the plastic mould steel. On this basis a follow up article in the next issue will concentrated on the more application oriented system properties of the three coating systems towards a polycarbonate melt. 相似文献
8.
Microstructure behaviour and influence on thermally grown oxide formation of double‐ceramic‐layer EB‐PVD thermal barrier coatings annealed at 1,300 °C under ambient isothermal conditions
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K. Bobzin N. Bagcivan T. Brögelmann B. Yildirim 《Materialwissenschaft und Werkstofftechnik》2014,45(10):879-893
To resist high thermal loads in turbines effectively, turbine blades are protected by thermal barrier coatings in combination with additional air cooling. State‐of‐the‐art yttria stabilised zirconia top coats do not operate at temperatures higher than 1,200 °C. Promising candidates for alternative top coats are pyrochlores, lanthanum zirconate and gadolinium zirconate. But lifetime of pyrochlores is short because of spallation. However, combinations of yttria stabilised zirconia and lanthanum zirconate or gadolinium zirconate as multilayer systems are promising top layers operating at higher temperatures than yttria stabilised zirconia. Such thermal barrier coatings top coats as double‐ceramic‐layer systems consisting of 7 wt.% yttria stabilised zirconia and lanthanum zirconate or gadolinium zirconate were deposited by Electron Beam‐Physical Vapour Deposition. The focus of the work was set on the influence of the coating design and the microstructure variation generated at different rotating speeds on the adhesion and thermally grown oxide behaviour after isothermal oxidation at 1,300 °C. Phase formation of the thermal barrier coatings top coats was obtained using X‐ray diffraction. After isothermal oxidation tests for 50 h at 1,300 °C, both, microstructure change and the formation of the thermally grown oxide were investigated. While the pyrochlore single‐ceramic‐layer are completely spalled off, microstructure of the double‐ceramic‐layer reveals only crack initiation. The thermally grown oxide thickness was determined by means of scanning electron microscopy. A high aluminum and oxygen content in the thermally grown oxide is found using X‐ray spectroscopy. Existence of α‐phase in Al2O3 was proved by X‐ray diffraction. After isothermal testing, no phase transformation can be detected regarding the double‐ceramic‐layer coatings. 相似文献
9.
Molly S. Bazilchuk Takashi Sumigawa Takayuki Kitamura Zhiliang Zhang Helge Kristiansen Jianying He 《Advanced Engineering Materials》2018,20(7)
10.
Nitridische und oxinitridische HPPMS‐Beschichtungen für den Einsatz in der Kunststoffverarbeitung (Teil 2)
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Prof. Dr. Kirsten Bobzin Prof. Dr. Guido Grundmeier Tobias Brögelmann Dr. Teresa de los Arcos Martin Wiesing Nathan C. Kruppe 《真空研究与实践》2017,29(1):24-28
Nitride and oxy‐nitride HPPMS coatings for the application in the plastics processing (Part 2) In the previous issue three oxy‐nitridic hard coatings on CrAl‐basis were investigated. These coatings were deposited by physical vapour deposition (PVD) as protective coatings against adhesive and abrasive wear in polymer extrusion. The coatings were developed using a variation of the oxygen content to investigate the influence of the chemical composition on the coating properties as well as composite properties between the coating and the coated tool. Following up on these findings this article will focus on the application oriented system properties of the three investigated coating systems towards the polycarbonate melt. 相似文献
11.
X‐ray diffraction (XRD)‐studies on the temperature dependent interface reactions on hafnium,zirconium, and nickel coated monocrystalline diamonds used in grinding segments for stone and concrete machining
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W. Tillmann M. Tolan M. Pinho Ferreira M. Paulus M. Becke D. Stangier 《Materialwissenschaft und Werkstofftechnik》2016,47(12):1193-1201
Diamond impregnated metal matrix composites are the state of the art solution for the machining of mineral materials. The type of interface reactions between the metal matrix and diamond surface has an essential influence on the tool performance and durability. To improve the diamond retention, the diamonds can be coated by physical vapour deposition with metallic materials, which enforce interface reactions. Hence, this paper focuses on the investigation of the interfacial area on metal‐coated monocrystalline diamonds. Hafnium and zirconium, both known as carbide forming elements, are used as coating materials. The third coating, which is used to determine its catalytic influences when applied as a physical vapour deposition (PVD)‐layer, is nickel. Additionally, the coated diamond samples were heat‐treated to investigate the starting point of the formation of new phases. X‐ray diffraction‐analyses revealed the assumed carbide formation on hafnium and zirconium coated samples. The formation temperature was identified between 800 °C and 1000 °C for hafnium and zirconium coatings. 相似文献
12.
Functional Layers on Metals: Tailored Properties by Sol‐Gel Technology The value of metal articles can be substantially enhanced by convenient surface coatings. Beside organic layers (e. g. paints) and inorganic layers (e. g. enamel) wellknown as coating materials, so‐called inorganic‐organic hybrid polymers set out to combine the advantages of both coating groups. For the manufacture of such hybrid materials functional particles with sizes of a few nanometers – so‐called nanoparticles – are synthesized in the sol‐gel process. The versatility of this procedure allows to cover an extreme variety of properties of the resulting layers. Thus, depending on their composition, sol gel coatings are suited as corrosion protection, as primer, as abrasion‐reducing coating or as easy‐to‐clean layer. A sufficient wetting and adhesion on vitually any substrate can be achieved by proper choice of functional groups and pretreatment steps. 相似文献
13.
In this investigation, a high power diode laser (HPDL) was used to induce the microstructural refinement on the surface of a SiC particulate (SiCp) reinforced Al-based metal matrix composite (A380/SiC/20p) and, at the same time, to the sintering of a sol–gel ceramic layer deposited on the surface of the mentioned substrate. The purely inorganic silica ceramic coating was synthesised through the organic sol–gel route, using tetraethoxysilane (TEOS) as alkoxide precursor and the dip-coating as the deposition technique on the surface of the A380/SiC/20p composite. Optimisation of the laser parameters led to homogeneous and free of cracking coatings and also to the refinement of the surface microstructure of the substrate by means of the dissolution of the intermetallic precipitates, the decrease in the aluminium dendrites size and a better distribution of the silicon carbide particles. Unlubricated pin-on-disc wear tests confirmed the increase (89% in terms of specific wear rate drop) in the wear resistance of the coated substrates treated by the HPDL. 相似文献
14.
I. El‐Araby Ali T. Lampke D. Wett T. Grund D. Nestler B. Wielage 《Materialwissenschaft und Werkstofftechnik》2014,45(6):445-455
Thermal barrier coatings (TBC) generally consist of a metallic bond coat (BC) and a ceramic top coat (TC). Co–Ni–Cr–Al–Y metallic super alloys and Yttria stabilised zirconia (YSZ) have been widely used as bond coat and top coat for thermal barrier coatings systems, respectively. As a result of long‐term exposure of thermal barrier coatings systems to oxygen‐containing atmospheres at high temperatures, a diffusion of oxygen through the porous ceramic layer occurs and consequently an oxidation zone is formed in the interface between ceramic top coat and metallic bond coat. Alloying components of the BC layer create a so‐called thermally grown oxides layer (TGO). One included oxide type is α‐Al2O3. α‐Al2O3 lowers oxygen diffusion and thus slows down the oxidation process of the bond coat and consequently affects the service life of the coating system positively. The distribution of the alloying elements in the bond coat layer, however, generally causes the formation of mixed oxide phases. The different oxide phases have different growth rates, which cause local stresses, micro‐cracking and, finally, delamination and failure of the ceramic top coat layer. In the present study, a thin Al inter‐layer was deposited by DC‐Magnetron Sputtering on top of the Co–Ni–Cr–Al–Y metallic bond coat, followed by thermal spraying of yttria‐stabilised zirconia (YSZ) as a top coat layer. The deposited Al inter‐layer is meant to transform under operating conditions into a closed layer with high share of α‐Al2O3 that slows down the growth rate of the resulting thermally grown oxides layer. Surface morphology and microstructure characteristics as well as thermal cycling behaviour were investigated to study the effect of the intermediate Al layer on the oxidation of the bond coat compared to standard system. The system with Al inter‐layer shows a smaller thermally grown oxides layer thickness compared to standard system after thermal cycling under same conditions. 相似文献
15.
16.
Dr. Jörg Vetter Cyndi Ackerman Dr. Frederic Meunier Dr. Olivier Jarry Dan Schumacher Dr. Georg Erkens 《真空研究与实践》2012,24(2):18-23
Different dLc coating types are applied at an industrial scale by sulzer Metco thin Film. The coatings are generated with different coating architecture. Deposition methods are: magnetron sputtering, electron beam evaporation and PA‐cVd. Reactive magnetron sputtering is used to deposit metal containing a‐c:h coatings (a‐c:h:Me), e.g. MAXit W‐ch. Pure a‐c:h coatings as functional top coatings are used for cavidur®, MAXit® AhdLc and special versions of dylyn® coatings. In addition to the pure a‐c:h coatings, doped a‐c:h coatings are also used. The dylyn® family of coatings is comprised of at least one layer a‐c:h:si:O. The dylyn® coatings may be doped with metal (a‐c:h:ti:si:O) to adapt selected properties like electrical conductivity. 相似文献
17.
MAKSIM KIREITSEU 《Particulate Science and Technology》2013,31(3):209-223
Fracture of Al-Al 2 O 3 -diamond-containing composite coating was investigated using rheological models for principal Hertzian contact of a sphere and a plate. The crystallographic and morphologic texture was characterized and the fracture resistance was measured using fracture mechanics. A rheological model of the composite coating was proposed and confirmed by in situ experiments. Examination of the composite coating showed a hardness value of 25 GPa (about 25% higher than for an alumina-based layer) and fracture resistance (about 50% higher than for a single oxide ceramic layer) as compared to prior alumina-based coatings on a soft substrate. Experiments revealed ultimate stresses and stress-strain modes of the coating. Diamond nanoparticles improved fracture resistance of an alumina-based layer. It is also thought that the composite coatings will have higher thermal conductivity and thermal shock resistance than alumina-based layers. Such physical characteristics suggest a number of possible commercial applications for the composite coatings, particularly for wear-resistant and related applications. The higher hardness and toughness of the coatings make them very attractive as substitutes for alumina-based and other ceramic-based composite coatings in these applications. composite rheology fracture stress indentation diamonds 相似文献
18.
为了提高金属基羟基磷灰石(HA)涂层的结合强度,采用复合电沉积一电沉积两步法在含Ti粉的钙磷电解液中制备HA—Ti/HA复合涂层,对涂层的组分结构、表面形貌、热稳定性、结合强度和生物活性进行了研究.实验结果表明:两步法制备的底层为HA—Ti复合涂层,外层为纯HA涂层的HA—Ti/HA复合涂层既提高了涂层的结合强度,又保证了涂层的生物活性.当涂层中Ti粉的质量分数为51.2wt%时,涂层与基体的结合强度达到21.2MPa,约为纯HA涂层的3倍.模拟体液浸泡7天后,涂层表面即被一层球状碳磷灰石覆盖,具有良好的生物活性,与纯HA涂层相比,复合涂层具有更好的耐蚀性能. 相似文献
19.
Maksim Kireitseu 《Particulate Science and Technology》2002,20(3):209-223
Fracture of Al-Al 2 O 3 -diamond-containing composite coating was investigated using rheological models for principal Hertzian contact of a sphere and a plate. The crystallographic and morphologic texture was characterized and the fracture resistance was measured using fracture mechanics. A rheological model of the composite coating was proposed and confirmed by in situ experiments. Examination of the composite coating showed a hardness value of 25 GPa (about 25% higher than for an alumina-based layer) and fracture resistance (about 50% higher than for a single oxide ceramic layer) as compared to prior alumina-based coatings on a soft substrate. Experiments revealed ultimate stresses and stress-strain modes of the coating. Diamond nanoparticles improved fracture resistance of an alumina-based layer. It is also thought that the composite coatings will have higher thermal conductivity and thermal shock resistance than alumina-based layers. Such physical characteristics suggest a number of possible commercial applications for the composite coatings, particularly for wear-resistant and related applications. The higher hardness and toughness of the coatings make them very attractive as substitutes for alumina-based and other ceramic-based composite coatings in these applications.
composite rheology fracture stress indentation diamonds 相似文献
composite rheology fracture stress indentation diamonds 相似文献