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The E.O. Paton Electric Welding Institute
Department of Protective Coatings.

Date of creation
10 Nov. 1985
The first Head of Department
Staff:
Professor

1
Doctors of Technical Sciences

4
Candidates of Technical Sciences

10
Senior Staff Scientists

8

Staff Scientists

2
Engineers

28
Technician

1


Activities in Science and Research.
Coating Deposition Technologies Coating deposition technologies used at the Department cover processes of thermal spraying, diffusion saturation, surface strengthening, spark alloying and micro-arc oxidation. In the field of thermal spraying the whole range of powder and wire spray processes is worked with. Different flame, arc, plasma and detonation spray processes are used within R&D projects to realise new material conditions.
These are:
  • powder and wire (incl. with cored wire) flame spraying (FS);
  • electric arc metallization (incl. with cored wires) (EM);
plasma spraying (PS):
  • plasma wire metallization (PWM);
  • detonation spraying (DS):
  • combined technologies: • plasma-detonation treatment processes (PDT); • flame spraying + plasma spraying.
  • traditional plasma (Ar, N2, H2, He):
  • atmospheric PS (40 kW) (APS);
  • micro PS (0.5-2 kW) (MPS);
  • air - gas plasma (air with propane, methane etc.) - AGPS:
  • subsonic AGPS (40 - 80 kW);
  • supersonic AGPS (160 kW);
  • PS with shielding nozzle (SPS);
  • PS with ultrasonic treatment;

The Department has developed the technology of diffusion for deposition of wear - resistant coatings from vanadium and chromium carbides. The process is performed in salt melts under atmospheric pressure and requires no shielding medium. Vanadium carbide and chromium coatings have thickness of 5 - 25 microns and microhardness of about 28000 MPa.

The technology of spark alloying is to transfer electrodes material on surface by electrical spark discharge. It permits to form coatings from different carbides and borides, metals and alloys (nickel, cobalt, silver, stannum etc.) and graphite to increase wear - and corrosion resistance and to decrease friction coefficient.

The method of micro - arc oxidation permits to produce on surface of aluminium or titanium and their alloys the coatings consisting from oxides or oxides with some additives. This is ecologically pure and economic technology which is realised in alkaline solutions. It produces coatings 50 - 400 micron thickness with porosity - 3 - 45 % and bond strength 20 - 250 MPa.

Surface Strengthening Technologies The Coating Department developed the technology of plasma-detonation strengthening of surface. This technology provides formation of hard layer up to 100 micron thick with microhardness of up to 18 GPa on steel and iron surfaces. A surface can be alloyed by titanium, tungsten, molybdenum and other elements. The plasma-detonation technology is realised in the air atmosphere without any preliminary preparation of a surface. The efficiency of plasma-detonation technology is similar to laser treatment, but it is simpler and has higher energy utilisation factor (up to 70%) and reliability. This technology is patented (European Patent Application 91907287.6 at 27.03.91).

The second surface strengthening technology, which is developed by the Department, is electrolytic-plasma quenching. This technology is used for local quenching of particular surfaces, as well as for increase in rigidity and strength of parts made of steel and cast iron. It uses water vapours as plasma-forming gas. The technology provides quenching of surface to the depth down to 15 mm with heating rate up to 1000 degrees/s.

Fundamental Investigations
In the of thermal spray theory the Department develops fundamentals of composite powders thermal spray process, of the deposition of thermal sprayed coatings with amorphous and microcrystalline structures. Computer model of plasma spray process is developed at the Department.
Fundamentals of composite powders thermal spraying includes an analysis of peculiarities of composite particles movement and heating in hot gas jets, processes of synthesis and interphase interactions, forming of coating layers. This permits to develop basic principles of composite powders design and rational technologies of their thermal spraying.
The Department has the priority in the theoretical analysis of amorphous structure formation in conditions of thermal spray process. A mathematical model is developed to estimate possibility of amorphous state formation, influence of different factors (material and temperature of base; material, size and temperature of sprayed powder particles; thickness of coating) on this process. This model is based on the combination of curves for the cooling of particles and the thermokinetic diagrams of a sprayed alloy in a single temperature-time field. The data obtained make it possible to evaluate the spraying conditions with which it is possible to apply coatings with amorphous (or microcrystalline) structures by the flame, plasma and detonation spraying methods.
The computer model of plasma spray process has been developed on the base of mathematical model. The main point of this model is that the problem of gradient heating and movement of individual particles is solved in combination with the analysis of plasma jet characteristics. This model makes it possible to calculate particle temperature velocity and trajectory of movement both under the free plasma jet emitting conditions, and in plasma jets emitting into a limited space: under the higher pressure conditions and in the presence of a protective nozzle CASPSP.
Development of theoretical and experimental principles of heat transfer during formation of composite metal-polymeric thermal-spray coatings, study principles of formation of the coating structures and the effect of a nature of organic and inorganic dispersed fillers on physical-mechanical properties, wear resistance under differing wear conditions and corrosion resistance, as well as new practical solutions on the application of the coatings in chemical engineering.

Material Development
Main directions of new materials development are composite powders and alloys for amorphous coatings. The techniques used by the Department for their production are gas atomisation of melts, conglomeration of mechanical mixtures by use of binders and by rolling and crushing, cladding of particles, self-propagated high - temperature synthesis and different technologies of cored wires production.
The original composite powders developed at the Department are Cr - SiC, Ti - SiC systems (to produce carbide coating with silicide matrix). Compositions of Cu - Ti, Cu - TiH2 are used to produce underlayers on copper and copper alloys surface, etc. Some composite powders are produced by self-propagated high-temperature synthesis. These are Cr3C2 - Al2O3, TiC -Al2O3, TiC - Al, Al - Si - TiC, Ti - Si - C, Ti - Cr - C, Ti - Cr - Fe - C etc.
Powders of AMOTEC series can be used for thermal spraying of amorphous coatings. They are produced by gas atomization method at experimental installation of EWI. Different cored wires for thermal spraying of wear resistant and anticorrosion coatings are developed at the Department. These are FeCrB, FeB, FeCrSiAl etc. which make it possible to produce coatings with amorphised structure; AlZn, AlFeTi03 etc. for corrosion - resistance coatings.

Main Research Subjects
The department is working with the following research and design projects:

  1. Development of new types of composite powders and cored wires for thermal spraying of wear - and corrosion - resistant coatings.
  2. Development of materials and technology for production of new amorphous and microcrystalline coatings with advanced properties.
  3. Investigation of space - time structure of dusted plasma jets within closed volumes (incl. with evaporating wall) at various pressures of external medium.
  4. Development of physico-chemical backgrounds of plasma - plasmochemical deposition of composite coatings with strengthening phase.
  5. Investigation of processes of local coatings formation by spark alloying and diffusion transfer of material into liquid mediums and development of new technologies to produce high wear - resistant coatings.
  6. Design of equipment and development of technology of supersonic air - gas plasma spraying.
  7. Design of equipment and development of technology of microplasma spraying.
  8. Design of equipment and development of backgrounds of plasma - detonation technology for strengthening of cutting elements of agriculture machines and processing industry, knives for metal cutting.
  9. Investigation of thermal spray process of electrochemically active coatings production and development of technology of coated anodes manufacture for the elaboration of new ecological systems of water treatment.
  10. Design of equipment, development of materials and technologies of thermal sprayed parts and units of boiler equipment and turbogenerators of power stations.
  11. Development of materials and of technology of thermal spraying of cavitation -resistant coatings for sleeves of diesels.
  12. Design of special equipment, development of materials and technology for deposition of wear - resistant and thermal barrier coatings on parts and units of internal - combustion engines and gas turbines.
  13. Development of materials and technology for protection of graphite electrodes of arc-melting furnaces.
  14. Development of materials and technology, design of equipment for plasma spraying of protective and decorative coatings on structural concrete constructions.
  15. Development of materials and ecologically pure technologies for deposition of protective coatings by thermal spraying methods instead of galvanic processes.
  16. Development of bioceramic coatings for implants and others medical articles.
  17. Development of materials and technology for production of polymer and metal -polymer thermal spray coatings.
  18. Design of special equipment and development of materials and technology arc spraying of anticorrosion coatings on tubes, structural constructions, tanks.
  19. Development of technology and design of complex for strengthening of parts and instruments by carbide coatings produced in salt melts.
  20. Design of equipment and development of technology for electrolytic quenching of agriculture machines parts and coal preparing equipment.
  21. Development of data bank and expert systems on protective and strengthening coatings.

Practical Activities.
Applications

  1. Wear - resistant plasma coatings on textile machines parts (8 works in Russia and Uzbekistan have produced up to 2 millions parts with coatings at 1990). Increasing of life time: 3 - 6 times.
  2. Cavitation - resistant thermal spray coatings (Konotop work produces about 700.000 sleeves with coatings per year). Increasing of life time: 1.5-2 times.
  3. Restoration of crankshafts and different others shafts by plasma and arc spraying.
  4. Heat and corrosion resistant coatings for boiler tubes and burners. Increasing of lifetime: 3 times and more.
  5. Anticorrosion thermal spray coatings for protection of bridges, tanks, tubes, structural construction. Lifetime: 15-30 years without repair works.
  6. Detonation equipment (Perun - S) and technologies for deposition of wear - and heat -resistant coatings on parts of gas turbines, space systems, engines, pumps etc. Increasing of lifetime: 2-6 times.
  7. Coatings for protection of graphitized electrodes of arc steel - making furnaces. Decreasing of electrodes consumption -15 - 20 %.
  8. Technology and equipment (Kiev-7 and Kiev-S) for air-gas plasma spraying of wear - resistant coatings on pumps parts.
  9. Carbide coatings for strengthening of matrix for deep drawing of metal punch, for cold pressing of powders, thread guides of textile machine, drills for paper etc. Increasing of lifetime: 3-30 times.
  10. Plasma - detonation treatment of knives, saws and different others cutting elements dies, punches, moulds. Increasing of lifetime: 1.5-8 times.
  11. Microplasma spraying of bioceramic coatings on detail implants, screws etc.

Equipment
Technological Equipment

E. 0. Paton Electric Welding Institute develops works to design new types of equipment for producing of coatings. Pilot plant of welding equipment produces experimental samples and small series of this new equipment. Main results of new equipment design are:

  • air-gas plasma spray installations "Kiev-7" (subsonic) and "Kiev-S" (supersonic);
  • microplasma spray installation VPS-003;
  • shielding nozzles for plasma spraying;
  • plasma wire metallization installation UN-126;
  • plasma spray installation for crankshaft restoring - UPDN-001;
  • detonation equipment complex "PERUN" (Perun-S, Perun-M, Perun-R);
  • flame powder spray installation UGPN-005;
  • flame wire spray installation UN-148;
  • arc spray gun AD-3 64.01;
  • plasma-detonation treatment complex UN-138;
  • automatic line for carbide coatings deposition.
Besides the Department has plasma installation UPU-8 and plasma spray complex OPN-11 for atmospheric plasma spraying, flame spray installation "Cyber Jet" (SNMI, France) and flame spray installation for low-melting materials UGPL, arc metallization installations KDM-1 and Hessler-1200A (OSU, Germany). Installations "Elitron-53" and "EIL-V8" are used for electric spark alloying of metal surfaces. Process of carbide coatings deposition performs in furnaces for heat treatment. Methods of Investigations For measurement of particles velocity is used ISSO - device, which operations by rotating mirror method. Structures of coatings are investigated by methods of metallography, optical and electron (scanning and transmission) microscopy, auger spectroscopy, X-ray diffraction analysis, X-ray microanalysis, image analysis, etc. Properties of coating are studied by methods of thermal analysis, high temperature differential thermal analysis, gas analysis; measurement of micro- and macrohardness, bond strength, porosity, testing of abrasive and gas - abrasive wear; potentiostatic measurement, etc.

 

International Projects
1986-1990
Cooperation in frame of the complex program of technological advance of the countries - members of COMECON in priority direction IV " New materials and technologies of their effecting and processing ", the problem 4.3.6 " Creation of new technologies of processing of materials with the use of plasma, vacuum and detonation technologies of deposition strengthening, wear- and corrosion- resistant coatings".
CSSR - Institute of a Plasma Physics, Prague; the Vitkovitskyi Metallurgical Centre, Ostrava;, Institute of Protecting of Materials, Prague. Poland - Institute Precision Mechanics, Warsaw; the Chestokchovskyi Polytechnic Institute, Chestokchov.
Hungary - Institute of Industrial Technology, Budapest.
Cuba - Metallurgical Institute, Havana.
Vietnam - the Research Machinebuilding Institute, Hanoi.
GDR - Polygraph Institute, Dresden.

1988-1991
Cooperation with Technical University of Tampere, Finland.

1990-1994
Cooperation in frame of the program EWISCO. * Material Science Institute, Aachen, Germany. * Institute for Surface Technology, Chemnitz, Germany. * Drexel University, Philadelphia, USA. * Powder Metallurgy Research Institute, Minsk, Belorussija.

1996-1999
Participation in fulfilment of the intergovernmental Ukraine-Holland program about technological cooperation:

  • The project FS-1 " Microplasma spray equipment ", 1996-1997, TNO, the Netherlands;
  • The project FS-2 " Microplasma spraying of narrow-strip coatings ", 1996-1997, Philips SMTI, the Netherlands;
  • The project FS-3 " Advanced Thermal Spray and Combined Technologies for Repair of Turbine Parts ", 1996-1997, Interturbine, the Netherlands;
  • The project FS-4 " Supersonic air-gas plasma spraying of thick layers ", 1997-1998, Habets Co., the Netherlands;
  • The project FS-13 " Wear and corrosion resistant carbide coatings from salt melts ", 1997-1999, Chromin Co., the Netherlands;
  • The project FS-14 "Redesign, manufacturing and assembly of an industrial microplasma machine ", 1998-1999, ECN, POMWELD Co., the Netherlands.

Participation in the European programs:

  • INTAS, 1993-1999 (93-2784, 94-672);
  • COST, 1994-1996 (p. COST-503-III);
  • Network MatMed, 1998-2001.

Fulfilment of the agreements about scientific-technique cooperation with the companies:

  • Magotteau Int., Belgium,
  • Metal Spray, USA,
  • Sant Luis Metallizing, USA,
  • Pecquet, Tesson, France, 1994-1995,
  • Sulzer Metco, Switzerland, 1999.

1997-1999
Running in the frame of STCU of the project 386 " Development of a complex of technologies of thermal spraying coatings for manufacturing radio- and electrotechnical parts ".

Publicaton:
 Books - 5;
Papers - more than 500;
Patents - more than 150.
AvtoSvarka - in Russian See latest The Paton Welding Journal

Address:

E.O.Paton Electric Welding Institute
11 Bozhenko St.
Kiev 03680
Ukraine

Tel: (380 44) 220 9215
Fax:(380-44) 220-9215
Borisov@pwi.ru.kiev.ua
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