Composite coating and method of its manufacture
(57) Abstract:The invention relates to multifunctional materials and can be used to form wear resistant composite coating on friction surfaces of the bearing and slide bearing, guides and other nodes of the machine parts from aluminum and its alloys. Composite coating contains a base of aluminum or its alloy and a layer of pyrolytic chromium, between the base and the layer of pyrolytic chromium placed intermediate layer oxidability. The thickness of the layer of pyrolytic chromium is 5-50 μm, and a layer of oxalacetate 50-300 μm. Method of forming a wear resistant coating includes forming oxide-ceramic layer based on aluminum or its alloy with micro-arc processing and pyrolysis of chromium carbide, with a layer of oxalacetate perform open on the surface porosity 3-10%, and when the pyrolysis mentioned porosity filled with chromium carbide. Effect: increase the load capacity of the coating. 2 S. and 1 C.p. f-crystals, 1 tab., 2 Il. The invention relates to multifunctional materials and can be used to form wear-resistant composite pin, made of aluminum and its alloy used in engineering and other industries.It is known that one way to improve the reliability and service life of the parts and components of machines, devices and equipment in conditions of intense friction is the use of wear-resistant coatings. Wear-resistant sliding surface in friction pairs formed by coating on the surface of parts of high-strength coatings using various technologies of their formation, for example, polymers, composite materials, solid lubricants, metal-ceramic materials.Known wear-resistant composite material and method of manufacture (ed. St. USSR N 221945, class B 22 F 7/04, publ. 1972).In this technical solution working layer of wear-resistant material applied on the base material, thus to improve communication working layer with the basis cause of the intermediate bonding layer of metal in the manufacture of a composite material is heated in a neutral atmosphere to a temperature above the melting point of the cementing metal. As a result, it melts, providing a secure connection between the working layer and materiamage layer the copper.A significant disadvantage of this material is the low load capacity of the working layer of tungsten carbide with localized (point or line) loading, as it is placed on the soft copper base, and it has a low hardness. To increase the load capacity requires a significant increase in the thickness of the working layer that with larger working surfaces leads to a significant appreciation of design, technology of its creation and, as a consequence, economic inexpediency of its use. In addition, the method of manufacture described material can not form the intermediate layer of copper on the substrate surface of aluminum and its alloy, the melting point of which is below the melting temperature of copper, which limits the scope.There is a method of creating a wear-resistant oxide-ceramic coatings by the method of microarc oxidation on the basis of aluminum or its alloy (ed. St. USSR N 1200591, CL C 25 D 11/02, publ. 1989).A significant drawback of oxide-ceramic coating is a high coefficient of friction in dry and boundary friction characteristic start and stop agennix with oxide-ceramic layer of the surfaces of the part. For this reason it is very important choose the best material and lubrication of the friction surface in contact with the surface of the aluminum oxide, which is not always possible for technological, structural, economic and other reasons, specific details, or the site.Known analogues of the closest to the technical essence of the present invention is the coating of pyrolytic chromium and method of its manufacture. (Yurchenko A. D. and other Protective coating of pyrolytic chromium: technology, properties, results of testing and application. - Dmitrovgrad, 1994, S. 3-5). In this technical solution working layer of chromium carbide is applied on the basis of aluminum or its alloy by pyrolysis liquids "Burgos" at the temperature of deposition 430. ..450oC, the vapor pressure in the deposition chamber 0,1...1,0 PA.A significant disadvantage of this coating is a low load capacity when it is applied to aluminum or aluminum alloy, as the layer of pyrolytic chromium, placed on a relatively soft base, pressed at a localized contact or linear loading. However, as the research showed, the increase in thickness deposited on the aluminium to olivosvicente significant internal stresses, promoting delamination of the coating, its destruction and, as a consequence, the loss of functionality of the node.The objective of the invention is to provide a wear resistant composite coating and its method of preparation, allowing to obtain increased load capacity.To solve the problem in composite coating on a base of aluminum or its alloy and containing a layer of pyrolytic chromium carbide, according to the invention, between the base and the layer of pyrolytic chromium carbide is placed intermediate layer from oxalacetate. The thickness of the layer of pyrolytic chromium carbide is 5-50 μm, and a layer of oxalacetate 50-300 microns.In the method of forming a wear resistant coating including deposition of chromium carbide by pyrolysis on the basis of aluminum or its alloy according to the invention, prior to deposition of chromium carbide on the basis of aluminum or its alloy using microarc oxidation to form a layer of oxalacetate with open porosity 3-10%, which when the pyrolysis is filled with chromium carbide.The best combination of physical and mechanical properties of adjacent materials in the coating provides a low coefficient of tridecylamine due to its inherent high strength and high (up to 300 microns) thickness. Low coefficient of friction provides a surface that is relatively thin working layer of chromium carbide. Due to the small thickness of this layer has a low level of residual stresses, and its penetration into the pores of oxalacetate not only provides high adhesion and high strength properties of the composite coatings due to the reinforcement of oxalacetate chromium carbide. When this reached the load capacity of the composite coating significantly exceeds the load capacity of its components separately (pyrolytic chromium carbide and oxidability).Reinforcement carbide chrome oxalacetate with the formation of strong boundary layer is provided by performing oxalacetate overlooking its outdoor surface then occupying 3-10% of the surface and having a diameter of 1 to 5 μm, and maintaining during the pyrolysis of ORGANOMETALLIC compounds (liquid "Burgos") vapour pressure 2-8 PA.High adhesion between the layer of oxalacetate and a substrate of aluminum or its alloy is immediate formation of the substrate material.The above values of the parameters of the coating layers, and the method of their formation is cytokeratine 50-300 microns attributable to the following. When the thickness of the layer oxidability less than 50 microns are open on the surface of the pores extend to considerable depth (40-60% of the thickness of the coating) and the local loading of oxalacetate rasklinivanie chromium carbide and prolamines at relatively low contact pressures. The creation of the thicknesses of the oxide-ceramic layers more than 300 μm is not economically feasible due to the sharp increase in the cost of their formation.Rational layer thickness of oxalacetate are selected in the range of 50-300 μm based on the loading conditions of a certain part in the operation.In Fig. 1 shows the microstructure of the composite coating.In Fig. 2 shows the microstructure of the boundary layer between oxidability and chromium carbide layer.Composite coating consists of oxalacetate Al2O3(mainly because of Al2O3and-Al2O3particles) formed directly from the substrate material (aluminum or its alloy) and a deposited layer of pyrolytic chromium carbide (Cr-CrC) (Fig. 1). The outer pores oxidability filled with chromium carbide (Fig. 2), which generally provides increased load capacity of the composite coating.On the outer layer of the sample material from aluminum formed using microarc oxidation layer oxidability Al2O3( basically-Al2O3and-Al2O3particles) with a thickness 40, 50, 100, 150, 200, 250 and 300 μm, with 7. . .9% open on the surface of pores with a diameter of 1.5-3 μm. The formation of the coating was carried out in the electrolyte based on the distilled water with the addition of 3 g/l solution of liquid glass with module 3 and a density of 1.5 g/cm and the addition of 2 g/l of sodium hydroxide NaOH at a voltage of 420 V and a current density of 20 A/DM2. Then on the layer oxalacetate was coated with the layer of chromium carbide by pyrolysis liquids "Burgos", which is a mixture of bissenova derivatives of chromium, mostly baatil and ethylbenzothiazolium. This liquid "Burgos" contains an additive to 3.5% of the volume of dimensional ether (C6H5CH2)2O. the Process of deposition of particles of chromium carbide on the surface of the heated parts produced under the following conditions:
- temperature vapor - 260oC;
- vapor pressure in the chamber of the deposition - 7 PA;
- the temperature of the substrate 430oC.Options include layers of composite coatings and the results of comparative assessment of their prochnosti the implementation and the method of manufacturing a wear-resistant composite coatings provide increased load capacity. 1. Composite coating on a base of aluminum or its alloy and containing a layer of pyrolytic chromium carbide, characterized in that between the base and the layer of pyrolytic chromium carbide is placed intermediate layer from oxalacetate.2. The floor under item 1, characterized in that the thickness of the layer of pyrolytic chromium carbide is 5 to 50 μm, and a layer of oxalacetate 50 to 300 μm.3. A method of manufacturing a composite coating comprising precipitation of chromium carbide by pyrolysis on the basis of aluminum or its alloy, characterized in that prior to deposition on the basis of aluminum or its alloy using microarc oxidation to form a layer of oxalacetate with an open porosity of 3 to 10%, which when the pyrolysis is filled with chromium carbide.
FIELD: metallurgy, namely chemical and heat treatment of refractory alloys, possibly used for applying protective coatings onto blades of gas-turbine engines.
SUBSTANCE: method comprises steps of applying onto inner and outer surfaces of parts diffusion aluminide coating in circulating gaseous medium; applying coating in low-active system at relation of reaction surfaces Fн/Fo = 0.3 - 0.7, where Fн - total surface of parts to be coated; Fo - total surface of saturating mixture; then applying onto outer surfaces of parts cladding coating, namely MeCrAlY, where Me - Ni, Co, NiCo by ion-plasma process or electron beam evaporation in vacuum.
EFFECT: improved fire and corrosion resistance of coating, increased resource of blades of gas-turbine engine.
1 cl, 1 ex, 1 tbl
FIELD: metal coats, in particular for gas turbine engines operating at high temperature.
SUBSTANCE: claimed metal coat contains (mass %) cobalt up to 18; chromium 3.0-18; aluminum 5.0-15; yttrium 0.1-1.0; hafnium up to 0.6; silicium up to 0.3; tantalum 3/0-10; tungsten up to 9.0; rhenium 1.0-6.0, molybdenum up to 10, and balance - nickel. Method of invention includes providing of support from at least one metal materials based on nickel, cobalt or iron followed by application of coating layer.
EFFECT: coats of high oxidation resistance and endurance strength.
33 cl, 1 tbl
FIELD: metallurgy, namely processes for applying wear resistant chrome carbide coatings, protection of surface of articles of titanium and its alloys against action of aggressive media, abrasive wear and high temperature influence.
SUBSTANCE: method comprises steps of applying sub-layer of metal and further applying of wear resistant chrome carbide layer by pyrolysis of chrome-organic compounds of bis-arene. Before applying wear resistant layer of chrome carbide, sub-layer of nickel or its alloys with thickness 0.1 - 10 micrometers is applied.
EFFECT: possibility for applying on titanium and its alloys wear resistant coating with enhanced adhesion degree of coating and substrate and with improved strength against crumpling at elimination of cracking.
4 cl, 1 tbl, 4 ex
FIELD: corrosion prevention technologies.
SUBSTANCE: method includes serial application of layers of polymer compositions to metallic surface, while serial layers of polymer compositions are made with various thermal expansion coefficients. As said polymer composition polyurethane compound is used with special admixtures and filling agent, influencing thermal expansion coefficient of covering layer, and content of said filling agent in each following layer is set less than content of said filling agent in previous layer.
EFFECT: higher efficiency.
2 cl, 9 ex
FIELD: electrochemical technologies.
SUBSTANCE: method includes dipping zinc-covered article in chromium-containing solution, prior to dipping electrolytic application of zinc is performed onto previously cleaned surface of zinc-covered article with following washing and drying, and after chromatizing article is dried by hot air.
EFFECT: protective cover, resistant to corrosion effect in atmosphere, polluted with industrial gases, and to effect from external loads of direct and alternating character, to provide for higher reliability and durability of article.
FIELD: mechanical engineering; methods of formation of shaped pieces out of a sheet steel.
SUBSTANCE: the invention is pertaining to the field of mechanical engineering, in particular, to the methods of formation of shaped hardware products from sheet steel. The offered method provides for a chemical-thermal treatment of slab billet in depth from the side of a form-shaping surfaces and a profiling. At that thus before realization of the chemical-thermal treatment conduct cleansing of the whole surface of the slab billet, on one or both cleansed surfaces superimpose a drawing determining the form of the bent pieces and on the determined area apply a layer of stannum or eutectics Pb-Sn, coat the rest area of the slab billet with a hermitic varnish, and the chemical-thermal treatment conduct by aluminizing. In particular cases of realization of the invention the cleaning is conduct by working. The aluminizing is carried out for 3-5 minutes: on a clean surface apply a drawing using a metallic pencil; a layer of stannum or eutectics Pb-Sn apply by a galvanic method. The technical result of the invention is application of methods of chemical-thermal treatment, in particular, the aluminizing for production of bent-shaped pieces with a protective coating.
EFFECT: the invention offers methods of chemical-thermal treatment, in particular, the aluminizing for production of bent-shaped pieces with protective coatings.
5 cl, 3 dwg, 2 ex
FIELD: working of steel products, possibly restoration of worn surfaces of cylindrical articles such as cylinders of sucker rod depth pumps.
SUBSTANCE: method comprises steps of mechanical working, iron plating of inner surface of article, carburization, chrome plating and further heat treatment with isotermal soaking at temperature of obtaining large-flake pearlite.
EFFECT: restoration of geometry parameters of inner surface of worn cylindrical articles, enhanced strength and predetermined surface roughness of articles.
FIELD: methods of hardening of restored surfaces of steel products.
SUBSTANCE: the invention is pertaining to the field hardening of metallic surfaces of steel products. The offered method includes a cyanidation of the electrodeposited layer of an iron-molybdenum coating within 1-4 hours at the temperature of 600-650°C with usage of a paste of the following composition (in mass %): yellow bloody salt - 30...45, sodium carbonate - 8...10, calcium carbonate - 5...10, carbon-black - up to 57. The technical result of the invention is boosting hardness and a wearability of surfaces of steel component parts.
EFFECT: the invention ensures an increased hardness and a wearability of surfaces of steel component parts.
FIELD: methods of production of antiemission coatings.
SUBSTANCE: the offered invention is pertaining to formation of coatings and may be used for production of antiemission coating on grids of powerful oscillating tubes. The offered method includes formation of a layer of the tube grid material carbide, application of a layer of zirconium carbide from a metallic plasma of the vacuum-arc discharge at the temperature of the grid above 300°C, formation of shaping of a surface layer of platinum and an annealing. The technical result of the invention is development of a method of production of the intermetallic antiemission coatingPt3Zr having improved operational features.
EFFECT: the invention ensures production of the intermetallic antiemission coating with improved operational features.
1 tbl, 4 dwg