The surface preparation method for plasma coating
(57) Abstract:The surface preparation method for plasma coating includes machining with the simultaneous influence of ultrasonic vibrations and static pressure, the maximum value of the amplitude of ultrasonic vibrations set at 18-20% more than the radius of the minimum particle size of the sprayed material. The invention improves the quality of the coating by increasing the strength of its adhesion to the basis and ensure homogeneity of the coating properties under specified conditions. 1 Il., table 1. The invention relates to mechanical engineering and can be used for preliminary preparation of surface for coatings.The known method of plasma spraying , which consists in the introduction into the plasma jet generated in the arc plasmatron, particles of coating material with the subsequent direction of flow on the surface. Due to the fact that the particles of coating material to a certain extent, melt, are accelerated and collide with the surface, which results in the formation of the coating.The main disadvantage of this method of plasmin MPa. To improve the adhesion of coating to the substrate is applied prior methods of processing the substrate surface.There are also known methods of preparing surfaces , including surface preparation blasting the oxide and the application of thermal spray coatings, which before the flapper oxide conducting surface plastic deformation blasting method balls made of high-strength steel, and the diameter of the balls is 2 - 3 mm, and the specific energy impacts on the surface during blasting treatment is 105- 106J/m2at specific time effects on the surface of 0.1 - 0.3 min/cm2.The disadvantage of analog is low adhesive properties of the coating, due to the lack of a transition zone between the base and the floor.In addition, the known method of surface preparation details  before coating thermal spraying, including Electromechanical processing surface of the workpiece by the tool at a pressure of 50 to 80 kgf/cm by passing electric current at the site of contact to melting and movement of the tool, and the processing performed by the tool with a profile about the but in the plane perpendicular to the processed surface with periodic off the electric current. The electric current is disconnected before moving the instrument up. Electric current is also cut off after contact of the tool with the surface.However, local melting leads to structural transformation, which in turn leads to a weakening of the strength properties of the material. The reciprocating movement of the tool and the melting of the metal causes a change in the metal structure, since sharp edges are stress concentrators, which reduces the fatigue strength of the metal.The closest in technical essence and the achieved result claimed is a method of coating , including preliminary machining of the surface of the product within 1 to 2 seconds and the application of the powder material with simultaneous machining the deposited layers, wherein the mechanical treatment is carried out at a pressure of 50 to 300 N with simultaneous influence of ultrasonic vibrations of a frequency of 16 to 20 kHz and an amplitude of 10 to 80 μm.The disadvantage of the prototype is a small amount of adhesion and essential to what toroi aim of the claimed invention, is to improve the quality of the coating by increasing the strength of its adhesion to the core and ensure homogeneity of the coating properties under specified conditions.This object is achieved in that in the method of surface preparation for coatings, including machining and simultaneous influence of ultrasonic vibrations and static pressure, in contrast to prototype create guaranteed the transition zone at the surface by introducing particles of coating material in the base.Maximum amplitude of the ultrasonic vibrations set at 18 - 20% more than the radius of the minimum particle size of the sprayed material.Surface properties embedded in it by the coating particles closer to the properties of the coating particles than those of the untreated surface. During subsequent plasma processing surface with uniformly embedded in it particles of the coating will provide a more intensive course of physical and chemical processes responsible for the strength of coupling. This is due to the chemical activity of the Foundation, provide a high level of plastic deformation and greater surface continetti, inherent in this method. Set ratio of amplitude of ultrasonic oscillations and particle size of the sprayed material minimize the number of idle strokes of the tool on the surface and ensures the formation of the transition zone. Mechanical action of the tool directly on the surface and not to the particles, it is undesirable. This does not lead to the formation of the transition zone, and it gets smaller.The main purpose ultrasonic waterjet processing - cleaning, strengthening and remove burrs and other surface defects. During the indicated operation, the workpiece is placed in a chamber with a water jet, and ultrasonic waves are radiated into the solution. The purpose of the radiation in the solution - cavitation destruction of burrs and additional processing abrasive grains. Upon the occurrence of acoustic streaming abrasive grains and the workpiece due to the different densities and sizes receive different speed. When mutual slippage of the abrasive grains and components deburring.Unlike waterjet processing, where ultrasonic vibrations are transmitted to the liquid, which contains abrasive particles in the claimed method of ultrasounds is UNT plays the role of the hammer, statically acting on the particles of the powder coating and periodically hitting them, introducing the particles into the surface. The organization of such a process allows to obtain a homogeneous and uniform transition zone containing particles of powder coatings, high surface roughness and the degree of plastic deformation, and as a result increases the adhesion strength and align its quantitative characteristics at different points on the surface.At the same time, the proposed solution differs from the known method of ultrasonic machining brittle materials, which is described in the works of Professor Markov, A. I. . These two compared methods have different goals. The first is the increase of adhesion of coatings by creating a transition zone containing particles of the coating and having a surface layer of high roughness and the degree of strain hardening, the second one - dimensional forming of brittle materials by chipping microscopic volumes. Ultrasonic dimensional processing is not used when forming materials having the criterion fragility 1<tx<2, because the effect of the introduction of grains in the surface is I positive because it allows you to form a transition zone containing particles of the coating and a rough surface with a high degree of plastic deformation. When processing the surfaces of solid materials introducing abrasive particles into the surface will not occur. However, micromicrocuries surface will allow you to create a measure of roughness, which is other ways to get difficult.Operation of the proposed method implemented by the device (Fig. 1) containing the processed base 1, through which particles of the coating material 2 in the treatment area, at the same time are affected by the tool 3 static pressure and ultrasonic vibrations.The essence of the method consists in the following. On the table ultrasonic installation fix the processed base 1. The powder particles of the coating 2 is injected into the treatment area and then simultaneously fail ultrasonic vibrations and static pressure from the tool 3 to the specified particle 2, which, taking root in the basis 1, create a transition zone, while providing a high surface roughness and the degree of plastic deformation of the substrate surface.An example of a specific implementation of the inventive method.The diameter of the ultrasonic vibrator tool 30 mm vibration Frequency of the ultrasonic vibrator 22 kHz, the oscillation amplitude of 20 to 25 μm. Pressing force of the tool to the workpiece surface (static load) - 50 N. Processing time 1 - 2 C. Preliminary surface treatment is carried out in a liquid medium. As abrasive particles were used camofluage powder PG-SR GOST 21448-75, the hardness greater than Hrc 45, a particle diameter of 40 to 160 μm. The weight ratio of abrasive particles and fluids 1: 2. After the surface preparation was carried out spraying of the same powder on the installation of the UPA-3M.The mode of deposition.Current, A - 350 10
Voltage - 55 2
The spraying distance, mm - 120
The plasma gas flow:
argon, m3/h 0,6
nitrogen, m3/h 0,03
The flow rate of the powder material, kg/h 0,6 - 0,7
The coating thickness, mm - 0,4
Comparative results of the proposed method and the prototype are presented in the table (see the end of the description).Thus, the claimed solution has a new feature - the ability to create guaranteed transitional PI surface, with the transition zone, characterized by high roughness and the degree of plastic deformation. These factors also contribute to improving the quality of the coating during subsequent plasma processing.Sources of information:
1. Hasui A. spraying Technique. M. "Engineering". 1975. 232 S.2. RF patent N 1804148, IPC6C 23 C 4/02, publ. 220.127.116.11. RF patent N 2068025, IPC6C 23 C 4/02, publ. 18.104.22.168. A. S. USSR N 1274328, MKI4C 23 C 4/02, publ. 15.03.93 prototype.5. Markov, A. I. Ultrasonic processing of materials. M Engineering. 1980. 237 C. The method of surface preparation for coatings, including machining and simultaneous influence of ultrasonic vibrations and static pressure, characterized in that the maximum amplitude of the ultrasonic vibrations set at 18-20% more than the radius of the minimum particle size of the sprayed material.
FIELD: oil-producing industry; mining; boring equipment.
SUBSTANCE: the invention is pertaining to the field of boring equipment and may be used at building-up of boreholes in the deep and superdeep drilling, and also at the open-cut mines at the blastholes drilling with blasting of the mine face by air. The method provides for the milling machining of each cog and deposition on it of an abrasive resistant protective coating. Before milling machining it is necessary to exercise turning machining of the inner and outer surfaces of the rolling cutter. After milling machining deposit an anticementing coating on the surfaces requiring protection against cementation. Then exercise cementation of the rolling cutter, its subsequent tempering in the oil, the low tempering, the bearing tracks grinding and coating by vapor deposition of an abrasive resistant protective coating on the cutter teeth and its intercrowned pits of the milling cutter. The protective coating has the hardness in the interval from HRC64 up to HRA72. Deposition of the protective coating is exercised, when the limiting temperature of heating-up of the rolling cutter does not exceed the temperatureof tn=280°C, at which the loss of strength of the cemented surfaces starts. The abrasive resistant protective coating is deposited in one or several layers till reaching the preset project depth of 0.2-0.8 mm. The technical result of the invention is the increased reliability of protection of the surfaces of the milled reinforced items against the wear and the increased mechanical resistance of the drilling bit as a whole.
EFFECT: the invention ensures increased reliability of protection of the surfaces of the milled reinforced items against the wear and the increased mechanical resistance of the drilling bit as a whole.
3 cl, 1 dwg
FIELD: metallurgy; restoration of working surface of crystallizer walls without disassembly of it.
SUBSTANCE: method of restoration of crystallizer walls made from copper and its alloys includes making notch, 0.5 mm deep at depth of wear of working surface no less than 1.0 mm. Then, working surface at depth of wear no less than 0.5 mm is subjected to shot-blasting after which precoat of thermo-reactive material, 0.1-0.2 mm thick and working layer of wear-resistant material are applied by gas thermal spraying. Depth of residual wear is no less than 0.5 mm.
EFFECT: enhanced resistance of coat.
FIELD: chemical industry; other industries; deposition of coatings by the gas-thermal methods.
SUBSTANCE: the invention is pertaining to the field of deposition of coatings by the gas-thermal methods, in particular, to the plasma deposition. The invention presents the method of preparation of the surface before the plasma deposition of chromium carbonyl. The method includes realization of the electrospark doping in the carbonic gas medium with utilization of the electrode formed from the powder on the basis of chromium. The doping is conducted at the following modes: the specific duration of the doping is 2-3 minutes/cm2, the discharge current - 0.6-0.9 A, the amplitude of the electrode vibrations is 60-70 microns, the frequency of the electrode vibrations is IOO Hz. The technical result of the invention is the increase of the cohesion strength of the gas-thermal coating with the substrate.
EFFECT: the invention ensures the increased cohesion strength of the gas-thermal coating with the substrate.
FIELD: metallurgy industry; mechanical engineering; other industries; methods of the vacuum-arc treatment of the metal products.
SUBSTANCE: the invention is pertaining to the field of the vacuum-arc treatment of the metal products before deposition on them of the coatings and may be used in metallurgy industry, mechanical engineering and other industries. The method provides for the vacuum-arc refining of the product-cathode and deposition of the coatings. Before deposition of the coatings the vacuum-arc refining is combined with the simultaneous complete or local oxidation of the surfaces, for example, up to the yellow, blue, violet, brown, black colors and-or tints and the combinations of the colors and tints. During the treatment of the long-sized products the local oxidation can be conducted in the form of the longitudinal and-or transversal straps and areas. The mode of the oxidation is exercised due to vibrations of the arc or the arcs, and-or due to for example the change - the increase of the power of the arc and-or the power emitted by the product caused by the electric current passing through it in the section from the electric current feeder from the power supply or the power supplies feeding the arc or the arcs to the product-cathode up to the electric arc or the arcs. The technical result of the invention is expansion of the technological capabilities of the method of the vacuum-arc treatment, improvement of the quality and the extension of the assortment of the depositing coatings.
EFFECT: the invention ensures expansion of the technological capabilities of the method of the vacuum-arc treatment, improvement of the quality and the extension of the assortment of the depositing coatings.
FIELD: technological process.
SUBSTANCE: invention is related to methods of surface preparation for plasma sputtering of coatings and may be used for cleaning of different surfaces with abrasive materials. Method includes abrasive treatment of surface that is subject to sputtering with thermal abrasive jet directed at the angle of 40...45° to processed surface. Jet is formed from high-temperature gas flow with abrasive loose material with fraction size of 0.3 - 0.7 mm. Processing is carried out until surface roughness is 40-50 micrometer, at that the mentioned surface is heated with high-temperature flow of gases up to 70 - 210°C.
EFFECT: provision of high-quality adhesion of coating with surface subject to sputtering.
SUBSTANCE: invention refers to methods of treatment of planing machine rollers. The method includes preparing of roller body surface and application of strengthening coating. Preliminary preparation of roller body surface is performed by means of its blowing-off under pressure with iron shot of 180...200 mcm fraction. Further two-layer strengthening coating is applied by the method of gas-detonation sputtering. Also the interior layer of coating is applied with powder of tungsten carbide of 55...65 mcm fraction obtaining thickness of the interior layer of 15...25 mcm. The exterior layer is applied with copper powder with additives not more, than 0.6%, obtaining the thickness of the exterior layer of 8...10 mcm.
EFFECT: upgraded wear resistance of sheet planing roller.
FIELD: technological processes, metal working.
SUBSTANCE: invention is related to the field of metal products cleaning, such as rolled wire, wire, strip, forged pieces, foundry and others, in particular, to method for electroarc processing of metal products surfaces and may find application in different branches of machine building industry. Prior to arc discharge treatment, surface is previously coated by thin layer of alkaline, alkali-earth or rare-earth metals or their compounds in process of hot processing or in cold condition. Prior to processing, at atmospheric pressure processed surface is previously coated by material, which is gasified by cathode spots of arc, creating protective or restorative medium above cleaned surface. Result achieved is considerable reduction of metal products processing cost, higher efficiency of processing and lower heating of processed product metal.
EFFECT: reduction of metal products processing cost, higher efficiency of processing and lower heating of processed product metal.
2 cl, 1 tbl
FIELD: textile fabrics; paper.
SUBSTANCE: invention relates to recovery method of diametric dimension of drier of paper-making equipment. After turning cut of cylinder it is implemented thermal processing of surface at temperature 100°C in passage area of electroarc burner. Then one-pass by material M470 it is applied the first adhesion layer of coating of solidity 360-420 HB of thickness 0.1 mm. It is applied the second filling layer by material ST-0002 of solidity 360-420 HB, thickness of which corresponds specified value of increase of diametrical dimension. It is applied the third coating cover of thickness 0.5 mm by material ST-0028 of solidity 250-270 HB, subject to allowance 1-2 mm for complete machining. Application is impregnated by compound "Hartz" in cooled condition, grind and polished the surface by flexible tool with providing of roughness Ra<0.63 micrometre, it is washed workpiece surface by mineral oil. After what it is run in surface of cylinder by edge scraping tool with angle of wedge slope 25°-30° and linear pressure 200-300 N/m.
EFFECT: it can be used in mechanical engineering at repair of driers without removal of it from the operation position.
FIELD: textile fabrics, paper.
SUBSTANCE: invention relates to paper-making manufacturing, particularly to application method of corrosion protection coating on working surface of rolling and creping cylinders and can be used at repair of rolling and creping cylinders without its taking off from operation position. After turning cut and thermal processing of surface one-pass it is applied the first adhesion layer of thickness 0.1 mm by iron alloy with chrome content 10÷13%. Then it is applied the second coating cover of thickness 2.0÷2.2 mm with content 13% of chrome and 27% of nickel. Then is implemented impregnation of coating cover by anticorrosive composition and grinding of operating surface by flexible tool.
EFFECT: receiving of cylinder with high processing characteristics, there are reduced expenditures for equipment repair and it is improved quality of paper, received with usage of mentioned cylinders.
FIELD: technological processes, metal working.
SUBSTANCE: invention is related to methods for preparation of flat steel cutting tools for operation, namely, to strengthening of cutting edges of disk scissors knives. Method includes preliminary processing of cutting edges by means of their blowing with coarse-grained abrasive and application of wear-resistant coat in them with thickness of 10…25 mcm. Coat is applied by means of gas detonation spraying of powdery mixture of chrome carbides on nickel binder with fraction of 55…60 mcm with pressure of 2900…3200 MPa during explosion of propane and oxygen mixture.
EFFECT: higher efficiency of cutting tool.
3 cl, 1 ex