DOCSLIB.ORG

Thermal Spraying

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Thermal Spraying Thermal Spraying Thermal Spraying DIN 32530: Thermal spraying comprises processes that feature: - full or partial melting of spraying feedstock (or at least sufficient heat transfer in order to provide a state of high plastic deformation capability) inside or outside a spraying torch - propelling of spray particles onto a prepared substrate surface - substrate surface is (usually) not melted Definition Heat and Momentum Substrate Transfer Spraying gun Energy source -Flame -Arc -Plasma Spraying feedstock -Powder -Wire -Rod Principle of Thermal Spraying Coating formation Thermal Spraying Spraying direction Pores Oxides Heat flux Lateral spreading Contact zones Impact of spray particles on substrates Pore Oxidized particle Not fully molten particle Substrate Formation of thermal spray coatings t = 0.00 µs -50 µm 0 50 t = 0.08 µs t = 0.03 µs -50 µm -50 0 µm 0 50 50 t = 0.13 µs d = 50 µm, v = 200 m/s Spreading of a AlPart. Part. -50 µm 0 50 2 O 3 particle on a substrate t = 0.23 µs -50 µm 0 50 t = 0.62 µs t = 0.36 µs -50 µm -50 0 µm 0 50 50 t = 5.00 µs d = 50 µm, v = 200 m/s Spreading of an AlPart. Part. -50 µm 0 50 2 O 3 particle on a substrate 15 30 45 60 75 > 75 P [MPa] t = 0.04 µs t = 0.10 µs -0.1 0.1 -0.1 0.1 mm mm t = 0.06 µs t = 0.23 µs -0.1 0.1 -0.1 0.1 mm mm t = 0.09 µs t = 0.36 µs -0.1 0.1 -0.1 0.1 mm mm Pressure distribution in an Al2O3 particle during spreading on a steel substrate white dashs: t = 0.62 µs solidification boundary -0.10 0.10 [mm] Temperature [K] t = 3.00 µs -0.10 0.10 > 1550 [mm] > 1300 >1050 t = 10.00 µs -0.10 0.10 >800 [mm] > 550 > 300 Temperature distribution in an Al2O3 spray particle during impact on a steel substrate Powder injection Free plasma jet v too low v optimal v too high Coating Substrate 2D view of particle trajectories for radial powder injection into a plasma jet Time to heat down to particle core [10-5 s] Target temperature: 1750 K Ni Flight time of particles Particle radius [µm] Time to heat particles down to the core Substrate surface temperature [K] Distance to particle center [mm] Substrate temperature distribution after impact of an Al2O3 spray particle Pre-cleaning Grit blasting (Ultrasonically Removal of Assisted) Cleaning Dirt Roughening Removal of Oil and grease Decontaminating grit blasting residues Paint, etc. Activating Pre-treatment of substrate surfaces Grit Sand (impermissible because of health risks) Alumina (corundum) Hard cast iron particles Steel wire chips Silicon carbide 40 µm < d Particle < 4 mm Pre-treatment of substrate surfaces Bonding mechanisms Mechanical interlocking Adhesion Diffusion in small microstructure areas Chemical bonding Electrostatic forces Bonding of spray coatings Bond strength is a function of interface temperature spray particle / substrate particle impulse at impact on the substrate properties of particle and substrate surface thermal conductivity of substrate and spray particles evolution of residual stresses in coatings Bonding of thermal spray coatings Bond strength is influenced by bonding mechanisms and coating residual stress state. - High tensile residual stress state can result in coating failure Bond strength > Coating strength Bond strength < Coating strength Bonding of spray coatings Spraying feedstock Thermal Spraying Hard material Zr Al W C B Cr Metal Mo Metalloid N Si Ti Ta V O Metallic hard material Non-metallic hard material Carbide Nitride Boride Oxide Nitride Carbide Cr32xCy TiN TiB2 Al2 O 3 BN SiC WC TaN ZrB2 Cr2 O 3 Si 3N 4 B 4C VC TiO2 ZrO2 Metal Metal Hardmetal Hard alloy Cermet WC/Co Fe-Cr-C-Base Co/ZrO2 WC/CoCr Co-Cr-W-C-Base Al/Al 2O 3 (W, Ti, Ta)C/Co Ni-Cr-B-Si-Base Material spectrum Powder 5 µm < dparticle < 120 µm Narrow powder size fractions ease optimization of process parameters and permit optimal coating properties. Drawback: high powder costs Spraying feedstock Powder geometry spherical (usually optimal) irregular (optimal only for cold gas spraying) spattered (not useful) hollow spheres (especially ceramics) „special development“ Spraying feedstock Powder types Homogeneous powder Composite powder melt atomized agglomerated and sintered fused and crushed mechanically clad precipitated (chemically) chemically clad SHS (Self Propagating High Temperature Synthesis) sintered and crushed mechanically alloyed (high energy milling) Powder production methods Crucible Molten metal Insert Cast opening Melt stream Nozzle Atomization medium Atomized particles Melt atomization open close-coupled NANOVAL Ma < 1 Ma = 1 Ma >< 1 Nozzle configurations for melt atomization In crucible In atomization chamber Vacuum Inert gas Inert gas Air Air Water vapor Influencing parameters of melt atomization - Atmosphere - Chemical composition Viscosity Surface tension Difference between melting and vaporization temperature Melt beam velocity Crucible diameter Influencing parameters of melt atomization - Melt - Gas or liquid Pressure Flow rate Velocity (nozzle design) Temperature Viscosity Influencing parameters of melt atomization - Atomization medium - Nozzle diameter Nozzle design (e.g. opening angle) Distance between insert and nozzle Height of atomization chamber Cooling medium (water or gas) Influencing parameters of melt atomization - Atomization conditions - Atomization Typical oxygen content Vacuum - Inert gas 40 ppm Inert gas - Inert gas 100 ppm Inert gas - Water 150 ppm Water 500 - 1000 ppm Gas content of melt atomized NiCrBSi powder Melt atomized NiCrBSi (gas / gas) Melt atomized Ni5Al (gas / water) Principle Melting and atomization of wires in converging plasma jets of three plasma torches Special process for melt atomization gas atomized water atomized Al, Cu, Ni, Mo, Ti Ni Al12Si FeCrNi, FeCrNiMo CuNi, CuAl CoMoCrSi FeCrNi, FeCrNiMo Ni20Cr, Ni5Al, NiCrBSi CoCrNiWTaC Ni20Cr, Ni5Al, NiMoAl, NiCrAl, NiCrBSi MCrAlY (M: Ni, Co, Fe) Ti6Al4V Typical melt atomized powder Principle After casting of melt into a mould and cooling the compact body is crushed and milled. Examples: Mo WC/Co Cr2O3, Al2O3, Al2O3 / TiO2 / Cr2O3 / MgO / SiO2 ZrO2 / Y2O3, ZrO2 / MgO, ZrO2 / CaO Fused and crushed powder Fused and crushed Cr2O3 powder Fused and crushed ZrO2 / Y2O3 93/7 Principle After sintering of fine powders and cooling the compact body is crushed and milled. Examples: Mo WC / Co, e.g. WC/Co 94/6 WC, WSC (WC/W2C) TiC, Cr3C2, NbC, TaC TiO2, TiO2 / Cr2O3, ZrO2 / Y2O3, ZrO2 / MgO Sintered and crushed powder Heat exchanger Gas distributor Gas filter Exhaust air Atomizer Exhaust fan Drying chamber Cyclone Suspension Powder channel Feeding pump Spray drying (Agglomeration) Atomization of suspensions proceeds by centrifugal forces on top of the drying chamber, where drying gas is also injected. - bucket shaped rotating, impeller and perforated wheel atomizers Spray drying by rotating atomizers Atomization of suspensions is carried out against force of gravity in a chamber with a swirled drying gas stream injected on its top. - long dwell time of agglomerates in the drying gas stream - only relatively small chamber required Spray drying by pneumatic nozzle Usually agglomerated powders are subject to thermal post-treatment (sintering) in order to improve the compound strength of the individual particles. -T < Tm (Tm of the compound is usually much smaller than the Tm of the components) - T < Temperature initiating impermissible metallurgical reactions (in particular exothermic reactions have to be avoided) - Atmosphere must be chosen adequately in order to avoid impermissible reactions Post-treatment of agglomerated powder Agglomerated and sintered Mo Metals Mo Cermets WC / Co(Cr), z.B. WC/Co 88/12, WC/CoCr 86/10-4 Cr3C2 / Ni20Cr, z.B. Cr3C2/Ni20Cr 75/25 Ceramics Al2O3 / TiO2, z.B. Al2O3 / TiO2 87/13 Al2O3 / Cr2O3 / MgO / TiO2 ZrO2 / Y2O3, z.B. ZrO2 / Y2O3 93/7 ZrO2 / CaO / CeO2 / MgO / SiO2 Typical agglomerated powders Principle By control of temperature, pH value and addition of neutralizing agents usually very fine powders are precipitated from salt solutions. Depending on the applied salts purity high purity products are possible. Usually agglomeration and sintering is required. Examples: usually oxide ceramic powders ZrO2, TiO2, CeO2 co-precipitation also permits production of multi- component oxide powders ZrO2 / TiO2 / CeO2 / HfO2 Precipitation of powders Principle: After activation and seeding of ceramic powder particle surfaces with palladium complete chemical cladding preferrably with Ni or Cu is carried out. Examples: Graphite - clad with nickel WC single crystals - clad with nickel Drawbacks: - High production costs - Long processing times Chemically clad powders Graphite powder chemically clad with Ni Graphite powder chemically clad with Ni process gas (inert / reactive) Pressure control ignition reaction front cooling water outlet cooling water inlet Principle of Self Propagating High Temperature Synthesis Igniter Reaction product Synthesis zone Reaction front Initial powder Principle of Self Propagating High Temperature Synthesis Chemical composition (incl. purity) Atmosphere (inert / reactive) Chamber pressure Cooling rate Initial powder particle size distribution Distribution of initial powder composition Controlling parameters of Self Propagating High Temperature Synthesis SHS laboratory reactor Reaction front propagation: 1 - 250 mm/s Synthesis temperature: 800 - 3500 °C Ignition temperature: 500 - 800 °C Temperature gradient: 105 -106 K/m Heating rate: 103 -106 K/s SHS reaction progress 20 µm TiC/Fe30Cr 55/45 SHS powder Principle: High energy ball milling auf powder mixtures is carried out with the aim to achieve alloy formation
Load more

Recommended publications
  • Porosity and Its Significance in Plasma-Sprayed Coatings
    coatings Review Porosity and Its Significance in Plasma-Sprayed Coatings John Gerald Odhiambo 1,2 , WenGe Li 1,*, YuanTao Zhao 1,* and ChengLong Li 1 1 Naval Architecture and Ocean Engineering, Merchant Marine College, Shanghai Maritime University, Shanghai 201306, China 2 Marine Engineering and Maritime Operations, School of Mechanical, Manufacturing & Materials Engineering, Jomo Kenyatta University of Agriculture and Technology, P.O. Box 62000-00200 Nairobi, Kenya * Correspondence: [email protected] (W.L.); [email protected] (Y.Z.); Tel.: +86-139-1799-6912 (W.L.); +86-151-2116-7661 (Y.Z.) Received: 11 June 2019; Accepted: 16 July 2019; Published: 23 July 2019 Abstract: Porosity in plasma-sprayed coatings is vital for most engineering applications. Porosity has its merits and demerits depending on the functionality of the coating and the immediate working environment. Consequently, the formation mechanisms and development of porosity have been extensively explored to find out modes of controlling porosity in plasma-sprayed coatings. In this work, a comprehensive review of porosity on plasma-sprayed coatings is established. The formation and development of porosity on plasma-sprayed coatings are governed by set spraying parameters. Optimized set spraying parameters have been used to achieve the most favorable coatings with minimum defects. Even with the optimized set spraying parameters, defects like porosity still occur. Here, we discuss other ways that can be used to control porosity in plasma-sprayed coating with emphasis to atmospheric plasma-sprayed chromium oxide coatings. Techniques like multilayer coatings, nanostructured coatings, doping with rare earth elements, laser surface re-melting and a combination of the above methods have been suggested in adjusting porosity.
    [Show full text]
  • View/Download PDF of This Article, the File Size
    INVESTIGATION OF STRUCTURE AND PROPERTIES OF THERMAL COATINGS OF WC—Co—Cr SYSTEM PRODUCED BY HIGH-VELOCITY METHODS OF SPRAYING Yu.S. BORISOV, E.A. ASTAKHOV, A.P. MURASHOV, A.P. GRISHCHENKO, N.V. VIGILYANSKAYA and M.V. KOLOMYTSEV E.O. Paton Electric Welding Institute, NASU 11 Bozhenko Str., 03680, Kiev, Ukraine. E-mail: [email protected] Spraying of coatings of WC—9Co—4Cr powder was performed by high-velocity procedures of thermal spraying, using the methods of detonation, supersonic air-gas plasma (SAGP) and oxy-fuel HVOF spraying. Microstructure and properties of produced coatings were investigated. Analysis of results of the coating structure examination showed that during spraying with these methods the dense coatings are formed, consisting of inclusions of tungsten carbide, uniformly distributed in Co—Cr matrix. Porosity of coatings is less than 1 %. Microhardness of SAGP- and HVOF-sprayed coatings is 11.0—11.7 GPa. As to the values of microhardness these coatings are superior to those of the galvanic chromium (10 GPa). Microhardness of the detonation coating is 8.5 GPa. The cause of decrease in hardness of the detonation coating is a partial loss of carbon and appearance of oxide inclusions in it, that is caused by the oxidizing medium of the detonation products. By the complex of characteristics of hardness, adhesion strength (more than 50 MPa) and porosity the coatings of WC—9Co—4Cr system, sprayed by SAGP and HVOF methods, are advantageous as compared with the galvanic chrome-plating. Among the investigated methods of high-velocity thermal spraying of coatings of WC—9Co—4Cr system the SAGP method is characterized by the highest efficiency (15 kg/h).
    [Show full text]
  • Microhardness Improvement by Using Thermal Sprayed Ni and Al Coatings by Detonation Gun
    e-ISSN (O): 2348-4470 Scientific Journal of Impact Factor (SJIF): 5.71 p-ISSN (P): 2348-6406 International Journal of Advance Engineering and Research Development Volume 5, Issue 04, April -2018 MICROHARDNESS IMPROVEMENT BY USING THERMAL SPRAYED NI AND AL COATINGS BY DETONATION GUN Mukesh kumar1, Mohd Vaseem2, Rajesh Kumar3 1Mechanical Engineering, Quantum University, Roorkee, India 2Mechanical Engineering, Quantum University, Roorkee, India 3Enginear, Welding/NDT, Engineeres India Limited RRFCL, Telagana, India Abstract - The present work was undertaken to increase the hardness of aluminium and nickel based coatings deposited by Detonation spray technique. The experimental work included deposition of Al2O3-TiO2 and Ni-Cr overlays of around 400 micron coating thickness, so as to achieve appropriate adhesion strength and hardness by using detonation gun spray technique (DS). Characterization of samples was made for further studies viz. as sprayed condition & post coating treatment. One of the hardfaced samples was subjected to post spray treatments of nitriding and compaction heat-treatment at 565° C for 2.5 hours and allowed to furnace cool, while another set of samples of both types of coatings was subjected to compaction at 12kN for 15 minutes. Systematic microstructural characterization of the coatings in the as-sprayed, nitrided conditions were carried out which included microhardness techniques in order to understand the effect of post treatment on the microstructure of these coatings. It is found that the microhardness values of base metal are enhanced almost three times after hardfacing/coatings with the Al2O3-TiO2 & Ni-Cr, using DS, which further enhanced after post treatment of nitriding and compaction.
    [Show full text]
  • Thermal Spraying of Polymer-Ceramic Composite Coatings with Multiple Size
    Thermal Spraying of Polymer-Ceramic Composite Coatings with Multiple Size Scales of Reinforcements A Thesis Submitted to the Faculty of Drexel University by Varun Gupta in partial fulfillment of the requirements for the degree of Master of Science in Materials Engineering April, 2006 i © Copyright 2006 Varun Gupta. All Rights Reserved. ii DEDICATION To my parents iii ACKNOWLEDGEMENTS I would like to express my gratitude to my primary advisor, Dr. Richard Knight, for his guidance, constant support and advice in many aspects of my graduate studies and research work but especially for the invaluable insights into thermal spray technology and a great influence on my professional development. I would like to thank my co-advisor, Dr. Richard Cairncross, for his always constant motivation, understanding, trust and support given throughout the course of my graduate studies. I deeply appreciate the friendship, assistance and practical help of Mr. Dustin Doss and Mr. Milan Ivosevic in working with me on this project, especially for the hands-on introduction to thermal spraying. I would also like to extend my thanks to Ms. Dee Breger for all her help during the SEM analysis and to Mr. Kishore Kumar Tenneti for assistance with the TGA analysis during the course of this project. I would like to give my special thanks to Mr. Ranjan Dash, Ms. Maria Pia Rossi, Mr. Davide Mattia, Mr. Brandon McWilliams and Mr. Stephen Niezgoda for their constant motivation and help. I also wish to thank all my friends, colleagues, faculty and staff members in the Department of Materials Science and Engineering who gave me the opportunity to learn from their advice and who have made my stay here at Drexel unforgettable.
    [Show full text]
  • Thermal Spraying Technology and Applications
    Thermal Spraying Technology and Applications Course No: T04-002 Credit: 4 PDH A. Bhatia Continuing Education and Development, Inc. 22 Stonewall Court Woodcliff Lake, NJ 07677 P: (877) 322-5800 [email protected] EM 1110-2-3401 29 Jan 99 1 EM 1110-2-3401 29 Jan 99 2 EM 1110-2-3401 29 Jan 99 DEPARTMENT OF THE ARMY EM 1110-2-3401 U.S. Army Corps of Engineers Washington, DC 20314-1000 Engineering and Design THERMAL SPRAYING: NEW CONSTRUCTION AND MAINTENANCE Table of Contents Subject Paragraph Page Chapter 1 Introduction Purpose 1-1 1-1 Applicability 1-2 1-1 References 1-3 1-1 Distribution Statement 1-4 1-1 Abbreviations and Acronyms 1-5 1-1 Neutral Language Use and Terms 1-6 1-1 Scope 1-7 1-1 Chapter 2 Thermal Spray Fundamentals Introduction 2-1 2-1 General Description of Thermal Spraying 2-2 2-1 Characteristics of Thermal Spray Coatings 2-3 2-1 Types of Thermal Spray Coatings 2-4 2-2 Thermal Spray Processes 2-5 2-3 Thermal Spray Uses 2-6 2-7 Chapter 3 Thermal Spray Materials Introduction 3-1 3-1 Specifications 3-2 3-1 Procurement 3-3 3-1 Classification 3-4 3-1 Acceptance 3-5 3-2 Certification 3-6 3-2 Sizes 3-7 3-2 Packaging 3-8 3-3 Identification and Marking 3-9 3-3 Manufacture 3-10 3-3 Testing 3-11 3-3 3 EM 1110-2-3401 29 Jan 99 Subject Paragraph Page Chapter 4 Thermal Spray Coating Cost and Service Life Introduction 4-1 4-1 Cost 4-2 4-1 Service Life 4-3 4-2 Chapter 5 Thermal Spray Coating Selection Introduction 5-1 5-1 Service Environments 5-2 5-1 Other Considerations in Coating Selection 5-3 5-4 Thermal Spray Selection for Ferrous
    [Show full text]
  • Design Concepts of Gaseous Detonation Guns for Thermal Spraying
    ɌȿKA. COMMISSION OF MOTORIZATION AND ENERGETICS IN AGRICULTURE – 2013, Vol. 13, No.4, 82-91 Design concepts of gaseous detonation guns for thermal spraying Yuriy Kharlamov1, Maksym Kharlamov2 1Volodymyr Dahl East Ukrainian National University, Molodizhny bl., 20ɚ, Lugansk, 91034, Ukraine, e-mail: [email protected] 2E.O. Paton Electric Welding Institute 11 Bozhenko St., Kiev, 03680, Ukraine, e-mail: [email protected] Received September 12.2013: accepted October 10.2013 S u m m a r y . Presented a structural analysis of gaseous processes have exposed that higher detonation guns for spraying powder coatings and the performance and lifetime coatings can be possible variants of their operational cycle. The basic principles for the design of high detonation-gas plants produced if the feedstock particles are for spraying powder coatings, including the concept of a accelerated to a high velocity and heated prior valveless devices, are formulated. to impact on the substrate to be coated [4, K e y w o r d s . Gaseous detonation, coating deposition, 13, 27]. operational cycle. Almost in parallel to plasma spraying, Union Carbide (now Praxair Surface INTRODUCTION Technologies, Inc., Indianapolis. IN) marketed the trademarked D-Gun producing premium In spite of competing processes coatings, especially metallic and cermet ones, (chemical vapor deposition (CVD), physical which have long been the goal of all other vapor deposition (PVD), etc.) and certain coating processes, i.e., higher density, drawbacks, thermal spray process sales are improved corrosion barrier, higher hardness, increasing regularly (almost by 10% per year better wear resistance, higher bonding and since 1990 [6]). The growth will probably cohesive strength, almost no oxidation, thicker continue, because spraying techniques are coatings, and smoother as-sprayed surfaces.
    [Show full text]
  • Application Notes Metallographic Preparation of Thermal Spray Coatings
    Metallographic preparation of thermal spray coatings Application Notes Thermal spraying was invented in the early 1900s using zinc for „metallizing” substrates for corrosion protection. The development of the plasma spray gun in the late 50s and 60s made it commercially viable to use high temperature materials such as ceramics and refractory metals for coating materials. In addition to fl ame and plasma spraying, today thermal spray methods include high velocity and detona- tion spraying using a multitude of different spray materials for the most diverse and demanding applications. Thermal spray coatings are applied to a substrate to give a specifi c surface quali- ty, which it originally does not have. Thus Metallography of thermal spray coatings the bulk strength of a part is given by the can have several purposes: substrate, and the coating adds superior - To defi ne, monitor and control spraying surface qualities such as corrosion, wear conditions for quality control or heat resistance. - For failure analysis Therefore thermal spray coatings are wide- - For developing new products. ly used in the aerospace and power gene- ration industry for new and refurbished The procedure normally involves coating sections and parts for jet engines and a test coupon to defi ne and optimize the gas turbines, compressors and pumps. process for the part to be sprayed. Sec- The properties of some coatings can only tions of this test coupon are then metal- be fabricated by thermal spraying, using lographically prepared and examined to mainly metals, ceramics, carbides and assess coating thickness, size and distribu- composites as well as mixtures of various tion of porosity, oxides and cracks, adhe- materials.
    [Show full text]
  • (12) United States Patent (10) Patent No.: US 6,852,433 B2 Maeda (45) Date of Patent: Feb
    USOO6852433B2 (12) United States Patent (10) Patent No.: US 6,852,433 B2 Maeda (45) Date of Patent: Feb. 8, 2005 (54) RARE-EARTH OXIDE THERMAL SPRAY 5.993,970 A 11/1999 Oscarsson et al. COATED ARTICLES AND POWDERS FOR 6,080.232 A * 6/2000 Sperlich et al.............. 106/436 THERMAL SPRAYING 6,582,814 B2 * 6/2003 Swiler et al. ............... 428/328 2002/0177001 A1 11/2002 Harada et al. (75) Inventor: Takao Maeda, Takefu (JP) FOREIGN PATENT DOCUMENTS (73) Assignee: Shin-Etsu Chemical Co., Ltd., Tokyo (JP) JP 2001-164354 A 6/2001 (*) Notice: Subject to any disclaimer, the term of this OTHER PUBLICATIONS patent is extended or adjusted under 35 U.S.C. 154(b) by 0 days. U.S. Appl. No. 10/101,612, filed Mar. 21, 2002, Takai et al. (21) Appl. No.: 10/618,679 U.S. Appl. No. 10/173,030, filed Jun. 18, 2002, Takai et al. (22) Filed: Jul. 15, 2003 U.S. Appl. No. 10/173,031, filed Jun. 18, 2002, Takai et al. (65) Prior Publication Data * cited by examiner US 2004/0013911A1 Jan. 22, 2004 (30) Foreign Application Priority Data Primary Examiner Jennifer McNeil (74) Attorney, Agent, or Firm-Birch, Stewart, Kolasch & Jul. 19, 2002 (JP) ....................................... 2002-211400 Birch, LLP (51) Int. Cl. ............................ B32B 15/04; B32B 9/04 (57) ABSTRACT (52) U.S. Cl. ....................... 428/697; 428/701; 428/702; 428/699; 428/469; 428/698 A rare-earth oxide thermal spray coated article comprising a (58) Field of Search ................................. 428/469, 701, Substrate and a coating layer formed by thermally spraying 428/702, 699, 698, 697: 106/474, 403, a rare-earth oxide thermal spraying powder onto a Surface of 479, 436 the Substrate, Said coating layer being of a gray or black color having, in the L*a*b* color space, an L* value of up (56) References Cited to 50, an a value of -3.0 to +3.0, and a b value of -3.0 to +3.0.
    [Show full text]
  • Properties of WC–10%Co–4%Cr Detonation Spray Coating Deposited on the Al–4%Cu–1%Mg Alloy
    materials Article Properties of WC–10%Co–4%Cr Detonation Spray Coating Deposited on the Al–4%Cu–1%Mg Alloy Marina Samodurova 1, Nataliya Shaburova 2,* , Olga Samoilova 2, Ahmad Ostovari Moghaddam 2 , Kirill Pashkeev 1, Vladimir Ul’yanitckiy 3 and Evgeny Trofimov 2 1 Resource Center for Special Metallurgy, South Ural State University, 76 Lenin Av., Chelyabinsk 454080, Russia; [email protected] (M.S.); [email protected] (K.P.) 2 Department of Materials Science, Physical and Chemical Properties of Materials, South Ural State University, 76 Lenin Av., Chelyabinsk 454080, Russia; [email protected] (O.S.); [email protected] (A.O.M.); [email protected] (E.T.) 3 Laboratory of Synthesis of Composite Materials, Institute of Hydrodynamics, M.A. Lavrent’ev SB RAS, 15 Lavrent’ev Av., Novosibirsk 630090, Russia; [email protected] * Correspondence: [email protected] Abstract: One of the methods of local improvement of the wear resistance of aluminum alloy parts is the deposition of hard tungsten carbide-based coatings on the surfaces subjected to intense external influence. This paper is devoted to the characterization of the WC–10Co–4Cr (wt.%) coating deposited on an Al–4Cu–1Mg (wt.%) alloy by the detonation spray method. In comparison with the common thermal spray techniques like High Velocity Oxygen Fuel (HVOF) or Atmospheric Plasma Spraying (APS), the heat input delivered to the substrate during detonation spray is significantly lower, that is especially important in case of coating deposition on aluminum alloys. The paper presents the Citation: Samodurova, M.; results of morphology investigation, microstructure, phase composition, microhardness, and cohesive Shaburova, N.; Samoilova, O.; strength of deposited carbide-based detonation spray coating.
    [Show full text]
  • SHS Powders for Thermal Spray Coating†
    SHS Powders for Thermal Spray Coating† T. Talako*, A. Ilyuschenko and A. Letsko Powder Metallurgy Institute1 Abstract The possibilities of preparing advanced powders for thermal spraying functional coatings by the method of self-propagating high-temperature synthesis are discussed in this review. Besides important economical and ecological benefits, the method allows the formation of powders with improved or unique structure and properties in size ranges and with an external morphology suitable for different thermal spray processes. A number of novel powders and recent achievements are presented. Keywords: self-propagating high-temperature synthesis, powder, thermal spray coating ent, depending on the spraying process, the operat- Introduction ing conditions, the desired properties of the final Modern industrial technologies call for the devel- coating, etc. Besides the intrinsic material properties, opment of novel materials with improved properties, the technical requirements for the TS feedstock pow- lower costs and environmentally suitable processes. ders include good flowability and sprayability. They Surface engineering that attempts to create func- are greatly affected by the particle size, shape and tional layers on the surface is obviously the most morphology as well as particle size distribution. That economical way to provide high performance to is why thermal spray feedstock powder production machinery and equipment. Among the wide range processes must be reliable and flexible, while remain- of available methods (including varieties of atomistic ing as inexpensive as possible. and particulate deposition, bulk coatings wetting Self-propagating high-temperature synthesis (SHS) processes and surface modification), thermal spray or combustion synthesis, discovered by A.G. Mer- coatings offer the most versatile solutions.
    [Show full text]
  • Detonation Thermal Spraying Process of Metal
    Technology Lappeenranta/Imatra Degree Programme in Mechanical Engineering and Production Technology Specialisation Andrey Vinogradov Detonation thermal spraying process of metal- ceramic coating of the inner body of a regulating valve for maintenance of turbine condensate level in a deaerator for a nuclear power plant Bachelor’s Thesis 2015 1 Abstract Andrey Vinogradov Detonation thermal spraying process of metal-ceramic coating of the inner body of a regulating valve for maintenance of turbine condensate level in a deaerator for a nuclear power plant, 41 pages, 3 appendices Saimaa University of Applied Sciences Technology Lappeenranta Degree Programme in Mechanical Engineering and Production Technology Bachelor’s Thesis 2015 Instructors: Lecturer Jukka Nisonen, Saimaa University of Applied Sciences Managing Director Zelenin Y.V., main process engineer Shvedov N.G., process engineer Karpenko D., Center of Scientific-Technical Service "Prometey" The objective of the research was to examine a process of metal-ceramic deto- nation spraying, technology and realization of the procedure and its features for the given component. The work was commissioned by main process engineer Shvedov N. G. This study was carried out at the Center of Scientific-Technical Service "Prometey". The information was gathered from internal documentation of the enterprise, manuals, literature and by interviewing process engineers. As a result of this thesis the detonation coating process was investigated for a particular unit – the regulating valve. All the stages and requirements were pre- sented. The results can be applied to any detonation coating case or surface treatment matter where complex approach is necessary. Keywords: coating, valve, deposition, spraying, mixture, powder, assembly, component, aluminum oxide, spraying gun, surface, nozzle, plunger, process.
    [Show full text]
  • Classic and Advanced Ceramics: from Fundamentals to Applications. Robert B
    Robert B. Heimann Classic and Advanced Ceramics From Fundamentals to Applications Robert B. Heimann Classic and Advanced Ceramics Related Titles Aldinger, F., Weberruss, V. A. Volume 4: Applications Advanced Ceramics and 2012 Future Materials Hardcover ISBN: 978-3-527-31158-3 An Introduction to Structures, Properties and Technologies Öchsner, A., Ahmed, W. (eds.) 2010 Hardcover Biomechanics of Hard Tissues ISBN: 978-3-527-32157-5 Modeling, Testing, and Materials 2010 Riedel, R., Chen, I-W. (eds.) Hardcover Ceramics Science and ISBN: 978-3-527-32431-6 Technology 4 Volume Set Krenkel, W. (ed.) Hardcover Ceramic Matrix Composites ISBN: 978-3-527-31149-1 Fiber Reinforced Ceramics and their Applications Volume 1: Structures 2008 Hardcover 2008 ISBN: 978-3-527-31361-7 Hardcover ISBN: 978-3-527-31155-2 Öchsner, A., Murch, G. E., de Lemos, M. J. S. (eds.) Volume 2: Properties Cellular and Porous Materials 2010 Hardcover Thermal Properties Simulation and Prediction ISBN: 978-3-527-31156-9 2008 Hardcover ISBN: 978-3-527-31938-1 Volume 3: Synthesis and Processing 2010 Hardcover ISBN: 978-3-527-31157-6 Robert B. Heimann Classic and Advanced Ceramics From Fundamentals to Applications The Author All books published by Wiley-VCH are carefully produced. Nevertheless, authors, editors, and Prof. Dr. Robert B. Heimann publisher do not warrant the information Am Stadtpark 2A contained in these books, including this book, to 02826 Görlitz be free of errors. Readers are advised to keep in mind that statements, data, illustrations, procedural details or other items may inadvertently be inaccurate. Library of Congress Card No.: applied for British Library Cataloguing-in-Publication Data A catalogue record for this book is available from the British Library.
    [Show full text]