Download or read book Ion Beam Deposited Metal Oxide and Fluoride Composite Coatings for High Temperature Tribological Applications written by and published by . This book was released on 1998 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Wide temperature, solid lubricant films offer payoffs for military turbomachinery components: rub seals, face seals, fretting interfaces and bearings. Multilayer films of B4C/Mo, B4C/Cr, Zn/W, Ni/Ti, Au/Cr, W/MoS and AlCuFeCr films were deposited by planar magnetron sputtering or ion bombardment assisted deposition (IBAD), and evaluated for adhesion, friction and wear properties from room temperature to as high as 1100 deg F. Oxidized Zn/W and W/MoS2 films exhibited low friction coefficients at room temperature. However, only AlFeCuCr quasicrystalline films consistently produced low friction coefficients at high temperature, suggesting that these films warrant further investigation. High friction coefficients obtained with IBAD Ni-Ti films at 1100 deg F were especially puzzling given previous Southwest Research Institute results that showed low friction values at high temperature.

Download or read book Physical vapor deposition and thermal stability of hard oxide coatings written by Ludvig Landälv and published by Linköping University Electronic Press. This book was released on 2019-04-26 with total page 42 pages. Available in PDF, EPUB and Kindle. Book excerpt: The state-of-the-art tools for machining metals are primarily based on a metal-ceramic composite (WC-Co) coated with different combinations of carbide, nitride, and oxide coatings. Combinations of these coating materials are optimized to withstand specific wear conditions. Oxide coatings, mainly α-Al2O3, are especially desired because of their high hot-hardness, chemical inertness with respect to the workpiece, and their low friction. The search for possible alloy elements, which may facilitate the deposition of such oxides by means of physical vapor deposition (PVD) techniques, has been the goal of this thesis. The sought alloy should form thermodynamically stable or metastable compounds, compatible with the temperature of use in metal cutting application. This thesis deals with process development and coating characterization of such new oxide alloy thin films, focusing on the Al-V-O, Al-Cr-Si-O, and Cr-Zr-O systems. Alloying aluminum oxide with iso-valent vanadium is a candidate for forming the desired alloys. Therefore, coatings of (Al1-xVx)2O3, with x ranging from 0 to 1, were deposited with reactive sputter deposition. X-ray diffraction showed three different crystal structures depending on V-metal fraction in the coating: α-V2O3 rhombohedral structure for 100 at.% V, a defect spinel structure for the intermediate region, (63 - 42 at.% V), and a gamma-alumina-like solid solution at lower V-content, (18 and 7 at.%), were observed, the later was shifted to larger d-spacing compared to the pure γ-Al2O3 sample obtained if deposited with only Al-target. Annealing the Al-rich coatings in air resulted in formation of V2O5 crystals on the surface of the coating after annealing to 500 °C for 42 at.% V and 700 °C for 18 at.% V metal fraction respectively. The highest thermal stability was shown for pure γ-Al2O3-coating which transformed to α-Al2O3 after annealing to 1100° C. Highest hardness was observed for the Al-rich oxides, ~24 GPa. The hardness then decreases with increasing V-content, larger than 7 at.% V metal fraction. Doping the Al2O3 coating with 7 at.% V resulted in a significant surface smoothening compared to the binary oxide. The measured hardness after annealing in air decreased in conjunction with the onset of further oxidation of the coatings. This work increases the understanding of this complicated material system with respect to possible phases formed with pulsed DC magnetron sputtering deposition as well as their response to annealing in air. The inherent difficulties of depositing insulating oxide films with PVD, requiring a closed electrical circuit, makes the investigation of process stability an important part of this research. In this context, I investigated the influence of adding small amount of Si in Al-Cr cathode on the coating properties in a pulsed DC industrial cathodic arc system and the plasma characteristics, process parameters, and coating properties in a lab DC cathodic arc system. Si was chosen here due to a previous study showing improved erosion behavior of Al-Cr-Si over pure Al-Cr cathode without Si incorporation in the coating. The effect of Si in the Al-Cr cathode in the industrial cathodic arc system showed slight improvements on the cathode erosion but Si was found in all coatings where Si was added in the cathode. The Si addition promoted the formation of the B1-like metastable cubic oxide phase and the incorporation led to reduced or equal hardness values compared to the corresponding Si-free processes. The DC-arc plasma study on the same material system showed only small improvements in the cathode erosion and process stability (lower pressure and cathode voltage) when introducing 5 at.% Si in the Al70Cr30-cathode. The presence of volatile SiO species could be confirmed through plasma analysis, but the loss of Si through these species was negligible, since the coating composition matched the cathode composition also under these conditions. The positive effect of added Si on the process stability at the cathode surface, should be weighed against Si incorporation in the coating. This incorporation seems to lead to a reduction in mechanical properties in the as-deposited coatings and promote the formation of a B1-like cubic metastable oxide structure for the (Al,Cr)2O3 oxide. This formation may or may not be beneficial for the final application since literature indicates a slight stabilization of the metastable phase upon Si-incorporation, contrary to the effect of Cr, which stabilizes the α-phase. The thermal stability of alloys for metal cutting application is crucial for their use. Previous studies on another alloy system, Cr-Zr-O, had shown solid solution, for Cr-rich compositions in that material system, in the sought corundum structure. The thermal stability of α-Cr0.28Zr0.10O0.61 coating deposited by reactive radio frequency (RF)-magnetron sputtering at 500 °C was therefore investigated here after annealing in vacuum up to 870 °C. The annealed samples showed transformation of α-(Cr,Zr)2O3 and amorphous ZrOx-rich areas into tetragonal ZrO2 and bcc-Cr. The instability of the α-(Cr,Zr)2O3 is surprising and possibly related to the annealing being done under vacuum, facilitating the loss of oxygen. Further in situ synchrotron XRD annealing studies on the α-Cr0.28Zr0.10O0.61 coating in air and in vacuum showed increased stability for the air annealed sample up to at least 975 °C, accompanied with a slight increase in ex-situ measured nanohardness. The onset temperature for formation of tetragonal ZrO2 was similar to that for isothermally vacuum annealing. The synchrotron-vacuum annealed coating again decomposed into bcc-Cr and t-ZrO2, with an addition of monoclinic–ZrO2 due to grain growth. The stabilization of the room temperature metastable tetragonal ZrO2 phase, due to surface energy effects present with small grains sizes, may prove to be useful for metal cutting applications. The observed phase segregation of α-(Cr,Zr)2O3 and formation of tetragonal ZrO2 with corresponding increase in hardness for this pseudobinary oxide system also opens up design routes for pseudobinary oxides with tunable microstructural and mechanical properties.

Download or read book Development of Ceramic Reinforced Iron Aluminide Based Composite Coatings for Wear Resistant Applications written by Mahdi Amiriyan and published by . This book was released on 2019 with total page 119 pages. Available in PDF, EPUB and Kindle. Book excerpt: Fe3Al intermetallic compounds and their composite coatings are potential structural materials for tribological applications. High-energy ball milled powders possess several advantages, especially cost-effective fabrication and lower cost of reinforcement. High-energy ball mill also allows for a wide range of reinforcement volume fraction. In this research, Iron Aluminide matrix composite coatings based on Fe3Al chemical composition with TiC and TiB2 particles were prepared using a high-energy ball mill and deposited via the High Velocity Oxy Fuel (HVOF) technique. The effect of processing parameters such as ball milling duration and subsequent heat treatment soaking time and temperature on the phases of products as a feed stock for the HVOF gun was studied. The processing parameters played important roles on the microstructure, mechanical and tribological properties of the coatings. The aim of the first experimental stage of this work was to study the effect of in-situ TiC particles on microstructure, mechanical and tribological behavior of HVOF deposited Fe3Al coatings. In this stage Fe3Al/TiC composite powders with different carbide quantities were produced via high-energy ball milling of Fe3Al-Ti-C system for 6 h followed by heat treatment at 1000 °C for 2 h under high vacuum. In-situ TiC-reinforced iron aluminide composite coatings were prepared to improve the Vickers hardness and wear resistance of Fe3Al intermetallics. The composite coatings mainly consist of a TiC phase uniformly dispersed within lamellae of the Fe3Al matrix. The composite coatings showed increasing Vickers hardness with increasing TiC content up to 70 mol% TiC. The dry sliding wear resistance of coatings was increased with the addition of in-situ formed TiC particles. HVOF deposited Fe3Al composite coatings with 50 and 70 mol% TiC reinforcements exhibited excellent sliding wear resistance. The dominant wear mechanism in those coatings was abrasion and oxidation. In another stage of this work Fe3Al-TiB2 composite powders with two different boride quantities were produced by the high Velocity Oxy Fuel (HVOF) spray deposition on a steel substrate. The composite coatings mainly consisted of a TiB2 phase uniformly dispersed within lamellae of the Fe3Al matrix. It was shown that by increasing the volume fraction of TiB2 both the Vickers hardness and sliding wear resistance of the coatings against alumina counterbody (6.33 mm in diameter) were increased. The increase of wear resistance was believed to be related to the hardness enhancement, which, in turn, is due to the presence of TiB2 particles within the Fe3Al matrix. The sliding wear rate of the coatings increased to reach a maximum as the sliding speed increases, and then it decreased with further increase of the sliding speed. The chemical analyses of the worn surfaces showed that higher sliding speeds result in higher oxidation of the surface, most likely due to the higher local temperature. Such an oxide layer seems to act as a barrier between two sliding bodies, thus decreasing the wear rate.

Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1994 with total page 892 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Advanced Tribological Coatings for Heavy duty Applications written by Mara Kandeva-Ivanova and published by . This book was released on 2016 with total page 147 pages. Available in PDF, EPUB and Kindle. Book excerpt: "The monograph "Advanced Tribological Coatings for Heavy-Duty Applications: Case Studies" reflects the last trend in solving wear problems. lt presents a summary of the researches conducted by the authors in the past few years, concerning the tribological coatings designed for different heavy-duty applications under the impact loads and high temperatures and pressures, in abrasive, erosive and corrosive environment. Three different deposition techniques and various coating materials were used and discussed, i.e. electroless plating process for deposition of nickel composite coatings with different nanoparticles (diamond, SiC and BN) addition; gas metal arc welding (GMAW) technique for hardfacing of different ferrous-based coatings; and high velocity oxygen fuel (HVOF) spraying process for deposition of various superalloy coatings."--Page 4 of cover.

Download or read book High Temperature Coatings written by Sudhangshu Bose and published by Butterworth-Heinemann. This book was released on 2017-11-27 with total page 418 pages. Available in PDF, EPUB and Kindle. Book excerpt: High Temperature Coatings, Second Edition, demonstrates how to counteract the thermal effects of rapid corrosion and degradation of exposed materials and equipment that can occur under high operating temperatures. This is the first true practical guide on the use of thermally protective coatings for high-temperature applications, including the latest developments in materials used for protective coatings. It covers the make-up and behavior of such materials under thermal stress and the methods used for applying them to specific types of substrates, as well as invaluable advice on inspection and repair of existing thermal coatings. With his long experience in the aerospace gas turbine industry, the author has compiled the very latest in coating materials and coating technologies, as well as hard-to-find guidance on maintaining and repairing thermal coatings, including appropriate inspection protocols. The book is supplemented with the latest reference information and additional support to help readers find more application- and industry-type coatings specifications and uses. Offers an overview of the underlying fundamental concepts of thermally-protective coatings, including thermodynamics, energy kinetics, crystallography and equilibrium phases Covers essential chemistry and physics of underlying substrates, including steels, nickel-iron alloys, nickel-cobalt alloys and titanium alloys Provides detailed guidance on a wide variety of coating types, including those used against high temperature corrosion and oxidative degradation and thermal barrier coatings

Download or read book Modern Tribology Handbook Two Volume Set written by Bharat Bhushan and published by CRC Press. This book was released on 2000-12-28 with total page 1760 pages. Available in PDF, EPUB and Kindle. Book excerpt: Recent research has led to a deeper understanding of the nature and consequences of interactions between materials on an atomic scale. The results have resonated throughout the field of tribology. For example, new applications require detailed understanding of the tribological process on macro- and microscales and new knowledge guides the rational

Download or read book Ion Beam Deposited Oxide Coatings written by CK. Carniglia and published by . This book was released on 1988 with total page 8 pages. Available in PDF, EPUB and Kindle. Book excerpt: Single-layer coatings of SiO2, Al2O3 and ZrO2 were deposited by ion beam deposition (IBD). IBD is carried out by directing an ion source at a target made of the desired coating material. The material sputtered from the target is directed toward the substrate being coated. The targets chosen for this work were commercially available hot-pressed oxides. To further modify the coating properties, a secondary ion gun was directed toward the substrate to assist the deposition. Thus, ion assisted deposition (IAD) can be combined with IBD. The following coating deposition parameters were varied: composition of the sputter deposition gas mixture, composition of the ion assist gas mixture, and beam voltage and beam current for the ion assist beam. No external heat was applied to the substrates.

Download or read book Tribology of Composite Materials written by P. K. Rohatgi and published by . This book was released on 1990 with total page 384 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Ceramic Abstracts written by and published by . This book was released on 1998 with total page 250 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book High power Ion Beam Deposition of Nanocomposite Multilayer and Single layer Metal Coatings written by and published by . This book was released on 2010 with total page 22 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Metals Abstracts written by and published by . This book was released on 1998 with total page 1042 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book The Foundations of Vacuum Coating Technology written by Donald M. Mattox and published by William Andrew. This book was released on 2018-08-21 with total page 383 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Foundations of Vacuum Coating Technology, Second Edition, is a revised and expanded version of the first edition, which was published in 2003. The book reviews the histories of the various vacuum coating technologies and expands on the history of the enabling technologies of vacuum technology, plasma technology, power supplies, and low-pressure plasma-enhanced chemical vapor deposition. The melding of these technologies has resulted in new processes and products that have greatly expanded the application of vacuum coatings for use in our everyday lives. The book is unique in that it makes extensive reference to the patent literature (mostly US) and how it relates to the history of vacuum coating. The book includes a Historical Timeline of Vacuum Coating Technology and a Historical Timeline of Vacuum/Plasma Technology, as well as a Glossary of Terms used in the vacuum coating and surface engineering industries. History and detailed descriptions of Vacuum Deposition Technologies Review of Enabling Technologies and their importance to current applications Extensively referenced text Patents are referenced as part of the history Historical Timelines for Vacuum Coating Technology and Vacuum/Plasma Technology Glossary of Terms for vacuum coating

Download or read book Introduction to Surface Engineering written by P. A. Dearnley and published by Cambridge University Press. This book was released on 2017-01-16 with total page 798 pages. Available in PDF, EPUB and Kindle. Book excerpt: This highly illustrated reference work covers the three principal types of surface technologies that best protect engineering devices and products: diffusion technologies, deposition technologies, and other less commonly acknowledged surface engineering (SE) techniques. Various applications are noted throughout the text and additionally whole chapters are devoted to specific SE applications across the automotive, gas turbine engine (GTE), metal machining, and biomedical implant sectors. Along with the benefits of SE, this volume also critically examines SE's limitations. Materials degradation pathways - those which can and those which cannot be mitigated by SE - are rigorously explained. Written from a scientific, materials engineering perspective, this concise text is supported by high-quality images and photo-micrographs which show how surfaces can be engineered to overcome the limits of conventionally produced materials, even in complex or hostile operating environments. This book is a useful resource for undergraduate and postgraduate students as well as professional engineers.

Download or read book Energy Research Abstracts written by and published by . This book was released on 1986 with total page 1200 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Engineered Materials Abstracts written by and published by . This book was released on 1993-04 with total page 850 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Metals Abstracts Index written by and published by . This book was released on 1996 with total page 1634 pages. Available in PDF, EPUB and Kindle. Book excerpt: