Method of hardening of gear wheels with the coating
The invention relates to machineoperating and can be used for finishing operations for hardening of complex geometric surfaces with the simultaneous application of composite coatings of ductile metals. The objective of the invention is to improve the quality of coverage, and the reliability of its adhesion with the base metal. The proposed method includes a preliminary hardening of the working surface, the flow in the zone of contact of the composition in the following ratio, wt.%: chloride copper 4-8, Anthranilic acid 8-10, ndimethylacetamide 5, urea 0,5, stearic acid, 0.5 to distilled water 15-20, the composition of ultrafine powders of copper and Nickel in the ratio of 1:1 2-4, glycerin rest, while the friction force in the contact zone reaches 10-12 N, and in the process of formation of composite coatings perform layer-by-layer hardening tool on the working profile, the optimal effort in the area of contact, applied to the tool, P = 2sinb[[n]/0,418]2/E, where f is the contact force, n;- the radius of curvature, mm; b - the working length of the line of contact, mm; E - fashion is permissible contact voltage, MPa. The technical result of the invention is to improve the wear resistance of the samples coated with the stated method of coating. 3 Il. The invention relates to machine to machine and can be used for finishing operations for hardening of complex geometric surfaces with the simultaneous application of composite coatings of ductile metals.Known method of applying a metallic coating, wherein the coating material is brought into the treatment area while its surface deformation due to static pressure instrument (SU 1504070, IPC 7 24 In 39/00, 30.08.1989).The known method of applying metal coatings using a rapidly rotating wire brushes, when the coating material is applied from a terminal donor located at the front of the workpiece surface, the latter is pressed against the pile of brush with a certain force (SU 1206068, IPC 7 24 In 39/00, 23.01.1986; SU 1540364, IPC 7 F 01 D 11/14, 30.06.1994).Closest to the proposed method is a method of hardening of gear wheels with a coating including a preliminary hardening of the working surface, the flow in the zone of contact of the composition containing the x powders of copper and Nickel in the ratio of 1:1, glycerin else (EN 2138579 C1, IPC 6 23 26/00, 27.09.1999).The disadvantages of the above methods is the inability to handle complex geometric surfaces gears, application of composite coatings insufficient adhesion to the basis and quality of the coating.The technical result improved quality of coverage, the reliability of its adhesion with the base metal, the ability to handle involute surface of the gear wheels is achieved by a preliminary hardening treatment involute surface of the gear wheels by air blast shot, or in some other way, where there is a reinforcing effect, such as enhancement of the hardness of the working surface, the formation of a favorable residual stress of compression, clean the surface from dirt. The coating process of preparation begins by running tool with a certain contact force or a possible offset of the axes of the installation. At this stage of treatment is reduced initial roughness of the working surface, is formed juvenile surface, which greatly facilitates the process of education preliminary diffusion layer and subsequently the coating.
In the process of formation of the surface is carried out layer-by-layer hardening treatment in the same tool. At this stage, the additional introduction of ultrafine particles included in the coating and the diffusion layer. Introduction copper coating of ultrafine particles of copper and Nickel allows to form a composite coating on the involute surface. An additional protection against direct contact of the rubbing surfaces. Layer-by-layer hardening treatment improves the quality of the coating.In the coating decreases the microhardness of the working surface by pokrytiya smoothed when hardening the coating treatment. This surface of the tooth in hydrodynamic mode slippage has smaller values of the friction force reduces the dissipation in the contact and allow for a greater work load on the teeth of wheels and as a result gear has a greater efficiency.To determine the best efforts of the pressing tool (creating pressure in the contact zone) uses the well-known formula of the contact stresses (formula Hertz)where PN- normal pressure in the contact is determined by the dependence ofTo determine the optimal effort (pressure) in the area of the contact surfaces of the workpiece and the tool is used dependencywhere f is the contact force, N;- the radius of curvature, mm; b - the working length of the line of contact, mm; E - modulus of the coating, MPa;
- angle gear deg;
[n] - permissible contact voltage [n] = 160150 MPa.The second limiting criteria process cover (defining permissible nagruzkakh see reference "machine Parts. Calculation and design" /under. Ed. N.With.Acherkan, ed. 3-E. - M.: Mashinostroenie, T. 1,-1968,-s.).
wherethe coefficient of sliding friction surfaces;
specific linear normal load in contact, N/mm;
VOCD- the speed of the sliding contact m/s, VOCD= |VK1-VK2|;
VK1VK2- the velocity of the contact point along the tooth, m/s;
given radius of curvature, m;
the radii of curvature of the profile of the mating tooth of the wheel at the contact point;
1,2- frequency of rotation of the wheel and tool, rad/S.It is established that the allowable temperature in contact in the absence of binding profiles of the tooth 250oC.The load value (estimated effort) in the treatment area may change due to the displacement of the axes of the tool and the workpiece surfaces on the wheel and the contact force, which is provided by the working spring installation for processing.Example contracepprevalence hardening (base material BKC-4). Scheme final processing involute surface of the toothed wheel shown in Fig. 1, 2. For material of this type is recommended composition, wt.%:
Chloride copper - 4-8
Anthranilic acid - 8-10
The ndimethylacetamide - 5
Urea - 0,5
Stearic acid - 0.5
Distilled water is 15-20
The composition of ultrafine metals (copper, Nickel in the ratio 1:1) - 2-4
Glycerin - Rest
After pre-hardening of the machined wheel 1 is mounted on the rim of the cartridge, for example, a lathe (see Fig. 1). In the tool holder of the machine (not shown) sets the body of the tool holder 2 in which is mounted a spring-loaded tool 3. Turn on the rotation of the details. Preparatory processing involute surface is carried out by a free spinning tool on the work surface, a member in engagement with the workpiece. The transverse flow of the caliper and the action of the operating spring 4 located in the housing, the optimum effort RV Voltage (force) occurring in the contact zone, controlled by the movement of the screw 5 relative to the body of the tool holder. Preliminary preload tube 6 provides the stability of pressure in the contact zone in proteina running reduces the initial roughness. In the process of formation of a coating (feed composition) is carried out layer-by-layer padding. The optimal number of liquids is determined by the formula:
Q=zb, l/m, - (5)
wherespecific application of the compound in contact (determined experimentally, about 2 g);
z - number of teeth;
b - the working length of the tooth.Preparatory phase the formation of the coating, its layer-by-layer hardening takes about 40-60 with when the wheel speed of 15-20 rad/S. the Calculation, the specific strength of the pressure contact is 30-40 N/mm2.Comparative evaluation of the quality of composite coatings was carried out on the kinetic parameters of the treated surfaces sclerometry and on the results of bench tests on samples. As the kinetic parameter was determined by the activation energy of surface coatings, with increasing numerical values which increases wear resistance of the surfaces. The original surfaces (uncoated) the value of activation energy reaches 15 kJ/mol, while the surfaces with the proposed composite coating 26 kJ/mol. Bench tests have proved that the wear resistance of samples with composition is adavani change of friction coefficient on time (EP properties) for different formulations is shown in Fig. 3.The proposed composition is prepared by alternately mixing followed by the addition of glycerol and ultrafine powders. The components included in the composition, non-toxic, environmentally friendly, safe in operation. For extended storage subsidence of ultradispersed powders, therefore, before application of the composition is thoroughly mixed.
Method of hardening of gear wheels with a coating including a preliminary hardening of the working surface, the flow in the zone of contact of the composition containing the chloride of copper, ndimethylacetamide, urea, stearic acid, distilled water, composition of ultrafine powders of copper and Nickel in the ratio of 1: 1 and glycerin, wherein the composition further comprises Anthranilic acid in the following ratio, wt. %:
Chloride copper - 4-8
Anthranilic acid - 8-10
The ndimethylacetamide - 5
Urea - 0,5
Stearic acid - 0.5
Distilled water is 15-20
The composition of ultrafine powders of copper and Nickel in the ratio of 1: 1 2-4
Glycerin - Rest
when this frictional force in the contact zone reaches 10-12 N, and in the process obrazovaniye force in the contact zone, applied to the tool
P = 2sinb[[n]/0,418]2/E
where f is the contact force, N;
- the radius of curvature, mm;
b - the working length of the line of contact, mm;
E - the modulus of elasticity of the coating, MPa;
- angle gear deg;
[n] - permissible contact stress, MPa.
FIELD: tool materials, namely tools for plastic working or cutting metals with strengthening coatings.
SUBSTANCE: tool includes hard alloy steel base with strengthening coating. Copper-nickel diffusion layer is used as strengthening coating; said layer is formed by diffusion saturation in melt of eutectic lead-lithium alloy to which copper and nickel are added. In variants of invention diffusion layer is formed in melt of eutectic lead-lithium alloy containing 5 - 10 mass % of copper and 2 - 3 mass % of nickel at temperature of diffusion saturation 1000 - 1200°C.
EFFECT: enhanced strength of tool, improved efficiency of process for plastic working or cutting metals.
2 cl, 2 ex
SUBSTANCE: invention relates to restoration of heat-resistant thermodiffusion aluminide coatings on gas turbine blades of complex configuration. The method involves removal of the worn-out area of the used coating and applying coating on the remote area by slipping layer-by-layer using suspension. The suspension consists of inorganic phosphatic - chromate binding substance and fine-dispersed aluminium and silicon powders. This is followed by drying and heat fixing of each layer. The finished coating is then thermodiffusionally annealed in vacuum.
EFFECT: coatings on the worn-out blades are no different by their properties from the coatings applied on new blades and operational life of the blades is longer.
5 cl, 3 dwg, 3 tbl
FIELD: machine building.
SUBSTANCE: procedure consists in application of coating on surface of steel item by diffusion saturation with nickel and copper, further, there is performed hardening thermal treatment of item by tempering from temperature of diffusion saturation and tempering. Coating is subjected to surface plastic deformation with rolling or shot-blasting at value of contact stresses in zone of deformation 3500…8000 MPa.
EFFECT: high operability of steel items and tool under hard usage with effects of high contact stresses, wear and influence of aggressive working mediums.
SUBSTANCE: procedure consists in cleaning and de-fatting sections of surface subjected to reduction, in application of layer of slurry composition on them and in successive drying. Composition includes mixture of binding filler containing powder of alloy of composition wt %: Ti - 15.0-40.0; Mo - 5.0-30.0; Y - 0.1-1.5; B - 0.5-2.5; Si - 26.0-79.4. Also, as binding in slurry composition there is used sol of silicon acid in volume ratio with powder of alloy from 1:3 to 3:1. Drying is performed in two stages - at room temperature during 30-60 min and at temperature 75±5°C during 10-20 min.
EFFECT: raised protective qualities of coating, avoiding burning operation.
2 cl, 4 dwg, 3 tbl, 3 ex
SUBSTANCE: lower end of a processed part is sealed, an auxiliary electrode is placed into a part, and a salt melt is loaded to the level by 2.5-3.5 mm lower the upper end of the processed part. The part is heated up to 830-1190 K, anode polarisation is carried out with current having density from 0.1 to 25.0 A/dm2 in a salt melt, being an electrolyte, during 1.5-3.0 hr with an auxiliary electrode. After anode polarisation the salt melt is poured out, and the part is cooled down.
EFFECT: increased microhardness and higher thickness of a protective layer of an inner surface of hollow parts.
1 tbl, 1 ex
SUBSTANCE: steel tool or carbide tool treatment method involves application of diffusion coating by saturation of steel or carbide tool in eutectic lead-lithium melt with addition of copper and nickel so that the coating is obtained. After application of coating the tool is strengthened by its being aged on material with hardness of 10 to 18 HRCe at value of contact stresses of 2000 to 5000 MPa during 2-5 minutes.
EFFECT: obtaining the coating having high stability to adhesion hardness, mechanical abrasion and deformation at maintaining positive operating properties of nickel-copper coating.
2 tbl, 2 ex
SUBSTANCE: diffusion coating is applied by saturation of tool surface of hard alloy in lead-lithium eutectic melt with admixtures of copper, nickel and iron. Iron plates are added to said melt to be arranged nearby tool surface in amount required for saturation of iron melt to weight concentration of 1-10% of the melt total weight.
EFFECT: higher tightness and wear resistance.
2 cl, 1 tbl, 1 ex
FIELD: technological processes.
SUBSTANCE: invention relates to technologies for increasing wear resistance of cutting, punching tools, as well as structural articles from hard alloy due to change composition and structure of their surface layers, and can be used for increasing resistance to mechanical and corrosion-mechanical wear. Method of diffusion saturation of the article from hard alloy in low-melting lead-bismuthic melt involves preliminary short-term high-temperature carbonization products and subsequent diffusion saturation of its surface in low-melting lead-bismuthic melt containing titanium in dissolved state and in which cobalt in powder or a compact form. Said cementation is carried out at temperature of 1,150-1,300°C for 10-20 minutes. Low-melting lead-bismuthic melt for diffusion saturation contains the following ratio, wt%: lead 38-48, bismuth 50-55, titanium 1-5 and cobalt 1-2.
EFFECT: higher wear resistance and operating life of items from hard alloys in conditions of high contact stresses, as well as efficiency of process.
1 cl, 1 tbl, 3 ex
FIELD: method for coating of superabrasive, in particular, diamond particles, with metal for manufacture of cutting tools, such as grinding or milling tools, or plated diamond articles.
SUBSTANCE: method involves using coating forming metal powder including compound; providing thermal reduction of metal from compound by placing superabrasive particles and powder adapted for forming of coating together into inert atmosphere; heating superabrasive particles and said powder to temperature of from at least 5000C to temperature below superabrasive destruction temperature during time interval sufficient for effective deposition of metal layer onto at least one portion of surface of each superabrasive particle and providing chemical bonding between said particles and said powder; cooling said particles and said powder to temperature below temperature of reaction between superabrasive particles and powder; separating mixture for obtaining of product fraction in the form of superabrasive particles coated with metal and substantially free from coating forming powder and by-product fraction in the form of coating forming powder substantially free from superabrasive particles coated with metal. Described are superabrasive particles coated with metal by means of said method, method for manufacture of abrasive tool with the use of superabrasive particles coated with metal, abrasive tool comprising said particles, and plated product comprising constructional diamond part and equipped with metal layer chemically bonded with at least one portion of surface of said constructive part.
EFFECT: provision for obtaining of material having superthin coatings of chemically active metal uniformly covering superabrasive over the entire surface of substrate.
27 cl, 2 tbl, 8 ex
FIELD: making stable surface coats by cathode spraying; spraying and precipitation of coats from baths or MOCVD; protection and modification of surfaces; solar-energy engineering.
SUBSTANCE: proposed method includes preparation of ceramic or oxide layers on substrates; after application and drying of initial substance, gassing with wet gas-reactant is performed for conversion into respective hydroxide or complex layer. Then heat treatment is performed for forming ceramic or oxide layer. For alternative making of other chalco-genide layers at increased conversion of substance, additional gassing is performed by means of chalcogen-oxygen containing gas-reactant. Metal layers may be obtained as alternative by means of reducing gas-reactant.
EFFECT: possibility of obtaining homogeneous coat in entire thickness of layers.
20 cl, 2 dwg