DE3390150T1 - Process for the manufacture of metal products - Google Patents

Description

DEAA-31771-5

Naming of the invention METHOD OF MANUFACTURING METAL PRODUCTS

Field of technology

The present invention relates to the field the pressure forming of metals and relates in particular to a process for the production of metal products.

Previous prior art

A method for machining blanks is known by pressing (GB-PS No. 1393143), which is the Yor coating of the blank with a solid, the creation of a lubricating film of liquid material between the coated blank and the transducer and Pushing it through an opening in the tool under the action of the pressure in the liquid material during movement of the plunger in contact with the liquid material.

In the known method, the transducer and the blank are heated to create a liquid lubricating film the melting of the previously applied coating either on the transducer walls or on the blank to. produce·

This method has a number of disadvantages. One One of these is poor quality of products when forming with heating because of the choice of heating temperature is the production of the liquid lubricant required by melting. You can use the Fracture zones on the surface and inside of the product as well as cracks in the solid coating. In addition, the finished product has a poor surface quality when using lubricants in the form of molten material as a result of those already mentioned Cracks mentioned.

In addition, the solid coatings mentioned in this patent specification have a limited plasticity s reserve, which affects its closeness and, as a consequence, the formation of cracks in the coating

"With high degrees of deformation, the quality of the Products deteriorate and the life of the press tool is shortened.

Also known is a hot isostatic pressing process (US Pat. No. 4,077,109) in which the as a shell trained transducers for hot isostatic pressing is made of alloys that are at press temperatures are superplastic. This method has a number of disadvantages, which are common to tray pressing are characteristic, u.zw. insufficient accuracy of the pressed parts due to uneven deformation the shell, an increased consumption of shell material in the case when the ratios for a uniform deformation of the pressed material are ensured, a limited use of the known method only in the field of Forming of semi-finished products from powder is open, which requires post-processing for the production of quality parts with specified properties A method for isothermal vision is also known Pressing of metals and alloys (SU copyright no. 651868.), after which the with a lubricant provided blank is heated and pressed in a temperature and speed range in which the material of the blank itself is superplastic, with the surface layer being formed prior to pressing a fine-grain structure "is treated The method is the resistance of the frictional forces and the uneven deformation as a result of a high level of technological deformability of the surface layer, which reduces is in the superplastic state when pressed. In the known method, they correspond to the conditions the superplasticity of the material of the blank, which has a fine-grain structure, corresponding to the temperature and speed ratios when pressing in the However, it does not rule the temperature and speed conditions that are required for the forming of the middle layers are required in which a fine-grain structure has not been created. Therefore the possibilities are one

Control of the forming conditions for the middle layers difficult, which leads to a reduction in the quality of the products. The decrease in quality comes into play Expression that the process has such quality requirements such as increased degree of deformation, high dimensional accuracy, specified degree of solidification and formation of a "certain structure of the pressed product is not fulfilled will.

A major disadvantage of the known method is the presence of an adhesive interaction between the surface layer of the blank and the contact surface in the state of superplasticity, of the tool during isothermal pressing under conditions of solid friction. This increases the surface quality of the products deteriorates and the service life of the tool is shortened. .

Ultimately, a method for reshaping metal blanks is known (GB-PS No. 1411999), in which a electrolytic precipitation of the surface layers the blank is provided, thereby facilitating its deformation will.

The surface layer through which the deformation facilitates contains accordingly over 99 * 99% pure aluminum, Cadmium, indium or zinc and is applied to the blank in the oxygen-free, anhydrous organometallic electrolyte electrolytically like. The forming can be done by pressing, compression molding, extrusion and drawing be carried out with the surface layer in front the forming can be heat treated. The forming is achieved by increasing the permissible degree of forming and extending the service life of the work tool as a result of better technological forming— the availability of the galvanic coatings used compared to the known coatings, which both For example, they can be used in cold forming and serve as a carrier for viscous lubricants.

However, by the known method the travel

exercise forces compared to the above procedure for surface treatment during cold forming as well as the non-uniform deformation across the product cross-section does not decrease, whereby the manufacture of Quality products with specified physical-mechanical Properties is made more difficult. Another disadvantage of the process is a limited area of application in terms of isothermal temperatures Forming as a result of a limited temperature range of the thermal stability of the galvanic coatings used. In addition, the galvanic coatings do not retain their closedness at high degrees of deformation due to a limited plasticity stock, which reduces the manufacturing accuracy of the products, the uneven- Deformation is also increased, the surface quality deteriorates and the service life of the tool is reduced be shortened. It should also be mentioned that through the process the direct adhesion interaction between the electroplated metal and the tool during the forming due to an increased ability the surface layer for pressure welding is not excluded is, whereby the quality of the product is further deteriorated. Due to the disadvantages mentioned the field of application for the method is limited mainly for the production of galvanically coated products from sheet metal or strip material with low degrees of plastic deformation is used.

The field of application of this process is also limited by the fact that the materials mentioned only can be applied by electrolytic precipitation can, as a result of which the manufacturing parameters of the process are worsened

Essence of the invention The invention is based on the object of such a Process for the production of a metal product to be removed by plastic deformation of the blank

winding in which the conditions for the maximum reduction in frictional losses during forming be ensured.

The problem posed is achieved in that in the production of Wet all certificates case plastic deformation of a blank on the surface of which a metallic coating layer is formed by the. the deformation is facilitated and that the plastic deformation is carried out by pressure deformation, According to the invention, materials are used as the material for the metallic layer, which at temperatures below the melting temperature of the blank material have superplastic properties, and the pressure forming at a forming temperature and speed is carried out in which a superplastic state is created in the coating material.

The advantages of such a method are that, under the conditions mentioned, the metallic layer forms a separating layer (a lubricant) between the contact surfaces of the blank and the forming tool during the transition to a superplastic state. Under the conditions of superplasticity, the separating layer has a unique combination of properties: an abnormally high plasticity of the coating material (2 to 3 orders of magnitude higher than under normal conditions) and low values of the deformation resistance of the coating material (1 order of magnitude lower than normal conditions) . Such a combination of properties of the separating layer avoids direct contact of the material to be formed with the tool at any high degree of plastic deformation during processing and the frictional stresses due to abnormally low values of the deformation resistance of the coating material are reduced. Ibungsspannungen is reduced by R _s the ungleichmäßig-

deformation speed decreases, which in turn increases it the formability as a result of a more complete utilization of the plasticity resonance of the to be formed Material leads. Thus, due to the lack of adhesion interaction., low values of the frictional stresses and high formability a better machining quality, u.zw. Dimensional accuracy, surface quality and similarity of properties is ensured. Be used as the material for the metallic layer Metals or alloys selected in which are below the melting temperature of the Eohlingswerkstoffes Temperatures the superplasticity effect occurs. The said Limitation is due to the fact that the deformation temperature during manufacture is below the melting temperature of the Eohlingswerkstoff it should be, because otherwise a plastic deformation of the Blank is not possible. On the other hand, due to the presence of a large group of metals and alloys, those at temperatures from 20 ° C to the melting temperature of the Eohlingswerkes superplasticity effect have, possible, a Ti with regard to the adhesiveness, the heat stability and the production-ready To choose the optimal coating.

Metals and alloys can be used as the material for the metallic layer, their temperature range the superplasticity with the mold temperature matches. For example, for the Cold plastic deformation is an alloy used, which in percent by mass: Nickel -. 0.5 to 2.1 Zinc - 35 to 76

Contains cadmium - remainder.

This composition ensures an improvement the shielding properties and an extension of the temperature range for the workability of the metallic Layer.

By introducing nickel into the composition of the lubricant, the shielding properties

Shafts are improved in terms of preventing hydrogen uptake by the blank surface during the electrolytic precipitation of the lubricant, because the hydrogen is absorbed by the kickel particles. On the other hand, the presence of nickel contributes in said composition in that the grains are crushed to a size of 0.5 to 2 Jim and a structure is formed which up to 30O ⁰ C ^r on heating against the Ko nwächstum is resistant, whereby a high superplasticity reserve of the coating (relative elongation 500 <fi) and a low shear strength (3.0 to 4.0 MPa) can be achieved and the temperature range of the working capacity is extended accordingly to 300 ^° C. The heating of the surface layers to the specified temperature values takes place through the heat generated during the deformation of metals at high degrees and speeds of plastic cold deformation.

purely the warm forming at temperatures up to 300 ⁰ C an alloy is expediently used, which in mass percent

Contains aluminum - 2 to 30 zinc - 70 to 98.

At forming temperatures of 400 to 700 ⁰ C, an alloy is used that is expressed in percent by mass

Contains copper - 50 to 62 zinc - 38 to 50.

This coating ensures the lubricating effect and thus improves the surface quality of the finished part.

This has a coating applied to the workpiece at the same time a protective effect and prevents the formation of hard oxides when heated when they get into the workpiece surface can be dented, causing cracks and other defects during plastic deformation.

9 ■ - '■:' ■ ;;; ■ ■

The metal coating according to the inventive method can be carried out using various known processes (electrolytic precipitation, treatment in warm solutions, Dipping in a molten material, etc.) that ensure sufficient adhesive strength '.,., of the coating with the blank material.

In the manufacture of products through spatial deformation in several stages, the coating applied by spraying on a suspension during the reshaping of the blank. This reduces the amount of work involved in manufacturing the products and in a number of cases increased the corrosion resistance of the products.

For forming temperatures of up to 400 ^° C., a suspension is used which contains titanium in percent by mass - 0.026 to 0.052 gallium - 2 _t 3 dis 5 aluminum - 10 to 20 mineral oil - remainder
contains.

Through the suspension mentioned, the shielding properties during plastic deformation and the Surface quality of the finished product improved. This effect is due to the deformation of a solid filler achieved in the state of superplasticity. The superplasticity the aluminum-titanium alloy with the superfine-grain The structure arises from the diffusion of liquid gallium into the alloy and is due to the formation of an easily melting boundary layer of the aluminum-gallium solid solution attributed to the grain boundaries.

When multi-stage compression molding, which includes in addition to the plastic deformation separation precedent, is not excluded by the present method, that of reducing the compressive forces and to improve the quality of the workpieces produced the metal coating, by the ⁿ in de temperature and velocity conditions, the formation of the Superplastizitätserffekts the Frictional

factor in the contact zone between the blank and the Tool significantly reduced, the forces in the process of plastic deformation reduced; and the Tension s is optimized to st and during the forming process, transferred to the molten state during the separating processes can be, whereby a substantial adsorptive strength decrease is achieved and consequently the separation forces are greatly reduced

A special pail is used when using the procedure for the manufacture of products through multi-stage deformation in which the surface solidification on the final deformation stage is provided, the deformation speed of the coating layer on the previous one Levels are chosen within the entire range of superplasticity of the coating material, and the final stage is the deformation speed the layer to a value within the superplasticity range restrict!; which ensures an advantageous deformation of the coating layer.

2Ö The method according to the invention makes the use of liquid and highly viscous lubricants (in addition to the metal coating), which the Reduce the friction factor, the adhesion of the coating prevent the tool, etc.

It is therefore expedient in the method according to the invention the lubricant immediately before the plastic To apply deformation to the coating

Brief description of the drawings

In the following, the invention will be explained with reference to concrete Implementation examples of the method according to the invention explained with reference to the accompanying drawing. It shows:

Fig. 1 - a schematic representation of a blank, which is inserted into a press tool for machining according to the invention.

The inventive method may be a pressing tool carried out by means which comprises a punch 1 and eine'.Matrize _"f 2 in which a blank 3

with the coating layer 4 applied thereon a material is inserted through which the plastic deformation is promoted and facilitated. Detailed examples of shift are given below different covering materials listed. Before the questions of the Before the choice of one or the other material is explained, the questions of the coating thickness are discussed.

Preferred embodiment of the invention

The initial thickness of the lubricating coating according to the method according to the invention "is according to the expression

Δ ₀ = A - η e ^{/ cL} (1)

chosen, where.

Δ - the initial thickness of the coating in jum; A - constant factor, which has a value from 10 to 15;

η - average grain size required for the

Generation of the superplastic effect is required, in jum;

6 - The intensity of the deformation of the coating during the deformation.

The expression (1) has been derived on the basis of the following assumptions:

- during pressing, the coating in its initial and the final shape is a hollow cylinder with diameters or a cross-sectional area

D, "E _n , d _b , d, f _n

dar, where

Dj ₃ , D - inside or. Outer diameter of the coating in the initial state;
^ n ~ cross-sectional area of the coating in the *

initial state;

djj, d - inside and outside diameter of the coating, respectively after pressing;

f "" cross-sectional area of the coating after Press.

■ rr- - the PlSchenv erha'ltni s is in the form of a

ⁿ ratio of the products of the corresponding average diameter to their thickness, ie in

expressed in which λ _o ^and * Δ - are the coating thickness before and after pressing;
the expression (2) becomes

converted j -ρ _

in expression (3) 1 -JP- = T (true relative

- Dv, + D ⁿ
Constriction) and I _n .. = <5 _r ( ^{wa} ire} radial deformation)

replaces _

_ - starting from the constant volume, ¥ and φ are expressed by the true elongation _cT »the known elations fr - f υ ^ -

applied j

~ the values ο are expressed by the intensity of the deformation. In the present case, the intensity of the deformation is £, - / <§j.

After the substitutions made, the Expression (3) look like this «

or Δ _ο = Δ _θ · .e. _O)

- the minimum thickness at which the superplastic deformation is ensured is determined according to the expression Δ _ο = A. η (6)

chosen.

The Δ value from IO to I5 corresponds to the minimum Number of grains at which the Komgrenaschlupf at the

superplastic deformation occurs;

- the average grain size (in microns) required for superplastic deformation . ... · ■■■■■

Substituting (6) and (5) gives expression (1).

According to (1), its final thickness remains independent of that Degree of deformation of the coating for superplastic flow sufficient, which ensures the working stability of the coating, as well as its cohesion during the entire process of isothermal pressing can be ensured, as can be seen from the derivation of expression (1) as a result it becomes clear that in this case the isothermal forming in the optimal temperature in terms of quality and speed range with high technological formability of the near-contact layers goes up · This is done in addition to reducing the resistance the frictional forces and the unevenness of the Deformation contributes to the production of quality products high degrees of deformation, with a high degree of dimensional accuracy, a specified degree of solidification, a certain Structure, etc. is guaranteed depending on the respective requirements for the quality of the products. the Speed coordination, i.e. the coordination of the deformation speed caused by the quality of the pressed part with that for the creation of the superplastic Flow required deformation speed, is in the method according to the invention by the possibility a differentiated selection of the coating material as well as the specific stress states of the coating easily achieved, whereby the superplasticity range is expanded in the direction of higher technological deformation speeds.

Through a differentiated selection of coatings, materials can be selected as the coating material that do not tend to be at isothermal temperatures Deformation to adhere to the material of the tool ..

In addition, the presence of a superplastic coating ensures that it is closed During the entire deformation process, the adhesion of the blank material is maintained with it the material of the tool prevented.

Specific examples of implementation of the invention are explained below.
Example 1.

According to the method according to the invention, shaping Hexagonal dies made of a steel (C - 0.80 to 0.88%; Cr - 3.8 ton 4.4%; W - 5.5 "to 6.5%; V-1.7 to 2.1%; Mo-50 to 5.5%; Fe - rest) by cold extrusion Manufactured by the quality requirements

a dimensional accuracy of the 1st accuracy class and a Surface roughness set at 0.032 Jim. The contact surface The blank was made with a cadmium-zinc-lfikkel alloy with a composition in percent by mass: Cd - 64.0; zn - 35.0 and Hi - 1.0 precoated accordingly. The coating was made by electrolytic precipitation applied, the initial thickness of the coating was 15-i 20 / in, the average grain size 0.5 lim. By using electrolytic precipitation, by which the for the occurrence of the superplasticity effect in the said Alloy required average grain size of 1-2 µm is achieved, a special treatment is required avoided to form a fine-grain structure. The extrusion was carried out at room temperature with the temperature of the emergence of the superplasticity effect in the Cd-Zn-Ni alloy over once; immt. For the Extrusion was a hydraulic press with an adjustment range of the forming speed from 0 to 26 mm / s used. During production, the deformation speed was 20 mm / s. The master tool became made of a tool steel according to the 1st accuracy class.

After extrusion, the dimensions and surface quality of the engraving meet the requirements

(Surface finish is 0.032 jam ), 1st class dimensional accuracy. The extrusion force is reduced by 40 f ₀ compared to extrusion using solid coatings and highly viscous lubricants.

Example 2.

According to the method according to the invention, shaping blind dies made of a steel (C- 0.80 to 0.88%; Cr - 3.8 to 4.4% j W -5.5 to 6.5%; V - 1.7 to 2 , 1%; Mo - 5.0 to 5.5%; Fe - remainder) produced by warm extrusion. The surface of the blank was precoated with a Cu-Zn alloy. Taking into account the necessary deformation temperature of 800 ⁰ C a Cu-39Zn alloy with 61% Cu and .5% Zn was used for the solid coating occurs in the at temperatures from 780 to 800 ⁰ C the superplasticity effect. The coating was applied by electrolytic precipitation, the thickness of the coating was 9 to 12 Jim, the grain size in the coating 0.5 The deformation speed was 15 mm / s. The improvement in quality is expressed in the absence of an adhesion interaction on the contact surface, as a result of which a high quality of the inner surface is achieved with high degrees of plastic deformation.

The application of the method according to the invention results the following advantages compared to known methods:

An increase in the manufacturing accuracy of the products with a high surface quality, which reduces the effort for mechanical post-processing is considerably reduced;

the possibility of manufacturing products with the required physical-mechanical properties that exclude post-treatment.

An evaluation of the possibilities of the invention mäjSen procedure based on the examples given with

the procedure according to the copyright certificate no. 65I868 has demonstrated that by the present invention:

1) in the production of hexagonal dies with deep cavities reduce the workload by 15 times, their service life in operation by 1.5 to 2 times lengthened, the metal utilization coefficient of the product is increased by 40%;

2) in the production of shaping dies with deep cavities the workload by 30 to 40% is reduced, the metal utilization coefficient of the product is increased by 40% and the manufacturing cost is increased by 30% off.

The method according to the invention will find wide application in metallurgy and in mechanical engineering in the manufacture of precision parts with predetermined operating characteristics. Example 3 _:

According to the method according to the invention, a fastening part made of a titanium alloy (Al - 5.5 to 6.5%; Mo- 2 to 3%; Cr - 0.8 to 2.3%. Si - 0.2 to 0.4% - Fe - 0.2 to 0.7%. Ti - Best) by direct Extrusion produced. By the quality requirements A dimensional accuracy of the 1st accuracy class and a surface roughness of O, O32jim was specified.

• The starting blanks with a diameter of 12 mm and a length of 18.2 mm were blasted with electro corundum and then provided with a coating of an aluminum-zinc alloy with 78 ic Zn and 22 # Al by metallization. The TJtformgrad during extrusion was 0.7. To form a fine-grain structure of the coating, the surface was ^{heated to 300 °} C., held for 5 s and cooled in water. The average grain size in the coating after the treatment was 1.0 µm. The initial thickness of the coating was 25 jum ^"wa s i ^m ^ determined according to the formula (1)

Zl "value matches. The deformation was carried out at temperature and speed ratios of superplasticity the Zn-Al alloy of the specified composition,

u.zw. "at a temperature of 260 ° C and a

- λ - 1 average forming speed of 10 - ^ s carried out on a hydraulic press. The forming tool was made of a steel (C - 0.80 to 0.88%; Cr - 3.8 to 4.4%; W - 5> 5 to 6.5%; V - I ₁ ? To 2.1 %; Mo - 5.0 to 5.5%; Fe - remainder).

A mixture of oil and 35% molybdenum disulfide was used as the liquid lubricant.

The quality of the products after forming corresponded the requirements. Example 4.

A test batch was made according to the method according to the invention made of self-locking nuts with an ellipse decrease. The processing included the following processes

- a pre-treatment of the surface of the starting bars from a steel (C - 0.14 to 0.18%; Cr - 0.8 up to 1.1%; Si - 0.8 to 1.2%; Ni - 0.9 to 1.1%; i'e - rest) with a diameter of 17 »3 now by chemical degreasing, Warm and cold rinsing in water, etching and cold rinsing in water;

- an upsetting on a cold upsetting machine in 6 Step, u.zw. Cutting the blanks to length from the rod, upsetting the rod sections, upsetting the blanks underneath

2- ¹ ? Formation of the thread bevel, extrusion of the cylindrical part, pre-forming of the hexagon and the cylindrical part, finishing of the hexagon, punching;

- Thread rolling on the inner surface of the perforated opening on a nut thread rolling machine; - Reduction in the ellipse of the cylindrical part of the nut.

During the upsetting and rolling processes, a water suspension of the finely dispersed metal powder of the cadmium-zinc-nickel alloy, which in percent by mass contains 64.0% cadmium, 35.0% zinc and 1% nickel, with a particle size of 8-10 μm. and a grain size in the particle of about 0.5 μm. The ratio of the metal powder to the distilled water was 1:10. The suspension

was prepared separately and fed into the cooling systems of the cold heading and nut thread rolling machines accordingly filled. The suspension was atomized with the aid of a pump built into the cooling system fed.

When upsetting was during extrusion of the cylindrical Part of the nut and the hole, the full forming force is detected by a measuring unit, which has a load cell glued on, in a bridge circuit without Amplifier-switched stretch-strip encoders and an oscilloscope included. Through the measuring unit, the Forces during the entire extrusion process with one relative deviation of max. 1 $ can be continuously recorded. The measurement results are in the table specified.

After production, the workpieces were tested for their appearance and corrosion resistance. The Appearance was checked visually to determine any puffiness, pores and disconnection of the coatings.

Corrosion resistance was tested using a rapid test method in a salt mist chamber. The exposure time in the chamber the maximum was chosen and amounted to 144 h. The workpieces on whose surface after No traces of rust found during the exposure time are considered to have been successfully checked. The test results on the appearance and corrosion resistance are also given in the table in the section "Process according to the invention".

- νέ'-

20th

table

Force values and quality of the workpieces manufactured using various processes

Serial production method Force values 5 6th at the ) Bemer No. at the Punch kungen Flow 7th press 4th 1 2 3 1 Inventory Ver 55 drive 80 2 Procedure with application 65 of aluminum 93 3 Procedure with application one phosphated 63 Coating 120 Table (cont. Appearance Resistant to corrosion speed 1

1 ready to use

2 closure errors on the Face and the thread surface

3 ready to use

There are sources of rust on the face, the thread and the cylindrical part

To the test results according to the invention Procedure and according to the. Procedure according to points 2 and To compare, test batches of the same workpieces were used manufactured according to two processes according to points 2 and 3, most widely used in domestic and foreign production of fasteners v / earth. . ,

The results of the comparative analysis show that the parts produced by the process according to the invention meet the requirements in terms of surface quality and corrosion resistance, the forces on the levels with the highest load being around $ 15 compared to the prototype and around $ 36 Extrusion and around. approx. 13 io lower when punching compared to the best-known method. The cited method does not meet the requirements with regard to quality and corrosion resistance as a result of defects in closure on the face and the thread.

The application of the method according to the invention in the Manufacture of metallic fasteners with a Thread has the following advantages:

- Reduction of labor involved in manufacturing at 20 56,

- Extension of the tool life by 1.5 to 2 times,

- Performance increase by $ 15>. Example 5

purely the test were cylindrical blanks with pf 18x9 mm made of aluminum alloys No. 1 and Mr. 2 selected with the following compositions · Mn - 1.0 to 1.6 #; Mg - 0.05 #; Al - balance or Mg - 5.8 to 6.8 %; Mn - 0.5 to 0.8 #; Ti - 0.02 to 0.1 #; Al - remainder. The lubricant according to the invention was applied to the surface of the samples by dipping.

The lubricant was prepared in the following manner, powder of Al-alloy 0,26Ti were mechanically in the liquid gallium in a weight ratio 4: 1 thoroughly mixed at a temperature of 50 ⁰ C, 7O ⁰ C and 100 ⁰ C, the first Ge ^m i ^sc h was kept at 50 ° C. for 15 h, the second mixture at 70 ^° C. for 60 h and the third mixture at 100 ^° C. for 120 h.

Thereafter, the mixtures were cooled to the room temperature (2Q ⁰ C). In the first mixture a diffusion of 1 </ ₀ gallium took place, in the second mixture a diffusion of

9 # Ga and in the third one of 20 % Ga.

The lower limit value of the gallium diffusion ($ 1) into the alloy is determined by the formation of the superplastic state in the Al-O.26Ti alloy and the upper limit value (20 <fi) by the maximum solubility (21 <f) of gallium in aluminum " definitely.

Mineral oil was then poured into the prepared mixtures, maintaining the stated ratio of the constituents, and mechanically mixed until a homogeneous mass was formed. For comparison, the powder of the Al-O.26Ti alloy was in the liquid according to the method for producing the lubricant Gallium mixed in the same ratio at 50 ⁰ C for 5 to 10 min, cooled to room temperature and mixed in the mineral oil. No gallium diffusion took place in the alloys.

For the comparative analysis, when pressing aluminum alloys the lubricant compositions given in the table were used.

table

Serial Composition of the no. Coating

Process for the production of lubricants

1. Mineral oil with graphite filler in the ratio 70 and 30 $

Mechanical mixing at room temperature

2. A mixture of 40% boron nitride and 60% aluminum powder

3. A mixture of 10% aluminum dust, 15% oleic acid and 75% mineral oil

4. A mixture of 10% powder of the Al-

Mechanical mixing at room temperature

Mechanical mixing of the aluminum dust with the oleic acid and the mixture produced in the mineral oil

Mixing Al-O.26Ti Alloy Powder ^:

- aft

Table (Ports.).

-O, 26Ti alloy, 2.5 gallium and 87.5% mineral oil

as in point

in liquid gallium

, Hold while

at 50 ° C

6. A mixture of 15%

powder of the Al-Oι26Ti alloy, 3.75% gallium and 81.25% mineral oil

7. A mixture of 20%

powder the. Al- -O, 26Ti alloy, 5% gallium and 75% mineral oil

15 h and mixing the mixture produced with mineral oil

Mixing the powder of the alloy in the liquid gallium at 50 ° C and the mixture produced in the mine; ral oil

H mixing the powder of the alloy in the liquid gallium at 70 ⁰ C, holding for 60 υad mixing of the produced mixture in the mineral oil

Mixing the powder of the alloy in the liquid gallium at 100 ° C, hold at 120 h, and mixing the mixture produced in the mineral oil

The composition of the coating according to points 4 to 7 is the one according to the invention, the compositions 1 to 3 are known.

The content of the Al-0.26Ti alloy powder for the coating depends on the operating conditions for the lubricant during pressing. Appropriately, the minimum amount of powder of the alloy (10%) at Pressing easily deformable aluminum alloys and the maximum amount (20%) used when pressing hard-to-deform aluminum alloys.

The coating with 10% powder of the Al-0.26Ti alloy became the easily deformable alloy when it was pressed No. 1 and with 15 and 20% powder when pressing the

Difficult to deform alloy No. 2 is used.

Before the coating was applied, the contact surfaces of the specimens and the tool were checked for a roughness from 1.0 jun. polished..

The blank with the coating was on a hydraulic Press tested with maximum pressing force 1000 Mp. The blanks and the tool were made by induction heated

After reshaping, the remnants of the coating were removed and the friction factor determined by the ball formation process · the surface quality was determined determined with a profilograph / profile knife.

The test results are given in the table *
15th

material table Lining variant Checks the temperature 2 ⁰ C 1 Al alloy 3 1 number 1 400 2 Al alloy 400 3 No. 2 Al alloy 400 number 1 20th - ·· - 20th 5 Al alloy 20th 6th No. 2 _ '»- 400 7th 400

Table (cont.)

Friction sf act or Cracks and Krat 5 surfaces zer present goodness jam 1 4th present 6th 1 0.15 present 2.3 2 0.19 present 2.0 3 0.14 none 1.8 0.10 none 1.6 0.08 none 1.1 5 0.13 none 1.5 6th 0.12 1.4 7th 0.11 1.3 Example 6.

.r Bin special bolt was made from a titanium alloy (Al - 1.6 to 3.8%; V - 4.0 to 5.0%; Mo - 4.5 to 5.5%; Ti - remainder).

Before eating, the surface of the blank is cleaned, pickled and coated with a metallic lubricant, namely a 10 to 12juun thick galvanic Cadmium-zinc-nickel alloy coating (Gd - $ 64, Zn- 35%, Ni - 1%) provided

The coated blank is formed on a crank press with a pressing force of 400 Mp. At the first stage

pe is the sheep u with an opening by direct extrusion produced and the head forwards by forging. shapes

Due to the large compressive stresses during plastic deformation, the speed range in which the superplastic effect occurs in the galvanic coating is extended to forming speeds in the order of magnitude of 10 ° ~ 10 s ~, which can be achieved with the press used. As a result of the converter heating, a temperature of 150 to 200 ^° C. is created on the workpiece surface. The temperature and speed relationships of the plastic deformation created in this way result in the creation of a superplastic

zitätseffektes guaranteed in the galvanic coating. Then the "workpiece" is heated until the galvanic coating has melted and the head becomes one Trimmed hexagon.

A comparison of the technological press forces at pressing a workpiece according to the invention a blank with a coating produced by thermal oxidation has shown that the technological forces during plastic deformation by 15 to 35% and for trimming by 8 to 12%

Example 7.

This example is manufacturing a high strength Special bolt made from a titanium alloy (Al - 1.6 to 3.8% $ V - 4.0 to 5.0%; Mo - 4.5 to 5.5%; Ti - rest) with a shaft for rolling up a thread M. 12 through multi-stage forming explained.

Before plastic deformation of the cylindrical blank from said titanium alloy (O ^ = = ÖÖ H / mm) is cleaned with a Kickelunterschicht to _v improving the adhesion with a metal plating of a cadmium-zinc Nickelr alloy (Ca - - 64.0%; Zn - 35.0%; Ni - 1%). The initial thickness of the applied coating is 15 Å and is determined from the formula (1).

The blank with the coating was placed in a press tool and on a crank press with 400 Mp Reshaped pressing force. The forming processes were carried out successively in the following stages: Reducing the Shank, top shapes of the bolt head, finished shaping of the head and repeated reduction of the shank. The preforming was carried out in temperature and speed ratios of the superplasticity of the metal coating carried out, which is conditioned by the following requirements will.

Due to the compressive stresses during plastic deformation, the speed range "in which the Superplasticity effect occurs in the galvanic coating, up to a deformation speed in the order of magnitude

extended by 5.10 s, which can be reached with the press ■ is.

As a result of the converter heating, a temperature of 150 to 200 ^° C. is created in the surface layer of the product. The superplastic nature of the coating material is ensured by the conditions created in this way. The deformation resistance of the coating is 9 »β to 29.4 N / mm and that of des

2
Blank material 88 N / mm.

On the final forming stages of the individual Workpiece parts are solidified. In In this example, the shaft, which was almost completely formed in the preliminary stage, is finished by calibrating in the last stage shaped, whereby the surface is solidified.

-j5 (At the same time, those for thread rolling shaped certain part of the shaft as well as the head).

in the example given, the surface strengthening achieved by the fact that the ratio of the deformation speeds of the last deformation stage Metal coating on the edge and in the middle of the contact zones of the blank with the tool (in the superplastic state and of the coating) is less than the ratio of the values of the deformation resistances of the blank material and the coating material in the superplastic state of the the latter is.

purely the comparative analysis was made from a part of the blanks the mentioned titanium alloy with an oxalate coating according to U.S. Patent No. 4023225 provided and saponified. The Umformvor-Sänge were carried out as shown above. The surface consolidation (rolling) then took place on a Thread rolling machine.

The pressing forces were registered during the forming process. The surface quality was measured with a profilograph / Profile knife determined. The geometric dimensions were with registered with a tool microscope.

The results of the laboratory tests are given in the table.

The results of the comparative analysis showed that the production of a special bolt according to the invention The process enables the roughness class to be improved from Ra 0.15 Jim to Ra 0.08 to achieve the geometrical accuracy of the 1st class and also reduce the forming force by 15 #.

table

Serial

No.

Thread size

Type of coating

Additional lubricant

JL

20th

M6

M12

M6

M12

Oxalate coating (+ saponification) according to the patent

Oxalate coating (+ saponification) according to the patent

Cd Zn Ni

according to the present invention

Cd Zn Ni

according to the present invention

Lubricant and coolant

Industrial oil

Table (cont.)

after Reshaping comment Accuracy height of class Micro uneven Shaft through heten (rough knife speed) 5 6th 7th 1 1-2 0.15jum 2 2 0.14 jam mistake in Form of pillow 3 1 0.10jum 0.08jum ^4th 1 0.1O ₇ ^

Industrial applicability

The inventive method is advantageous for Pressing, compression molding, extrusion, drawing and other processes for pressure forming are used and Can be used in mechanical engineering for the production of workpieces .. with a complicated profile made of steels that are difficult to deform and alloys are used.

Claims (10)

Claims . 1. Process for the production of metal products by plastic deformation of a blank, which consists in that a metallic coating layer is formed on the blank surface through which the deformation is facilitated, and the plastic deformation is carried out by compression molding, thereby g e k e η η ζ eic h η e t that as a material for the metallic Layer (4) a material is used, which is under the melting temperature of the blank material Temperatures has superplastic properties, and the pressure forming at a forming temperature and speed is carried out where in the material the coating layer becomes superplastic. 2. The method according to claim 1, characterized in that the material for the coating Metals and alloys are used, in which the temperature range of the superplasticity with the forming temperature matches. 3. The method according to claim 2 for plastic cold deformation, characterized in that that an alloy of the following composition in mass%: Nickel - 0.5 to 2.1 Zinc - 35 to 76 Cadmium - remainder
is used. .20 4. The method according to claim 2 for pressure forming at forming temperatures of 20 to 300 ° C, characterized characterized in that an alloy of the following Composition in% by mass: Aluminum - 2 to 30 Zinc - 70 to 98 .. · '... is used. 5. The method according to claim 2 for pressure forming Forming temperatures from 4 00 to 700 ° C, characterized in that an alloy of the following Composition in% by mass: Copper - 50 to 62
Zinc - 38 to 50
is used. 6. The method according to claim 1 to 5 for the production of products by spatial deformation in several stages, thereby g e k e η η ze rejects that the coating is applied during the reshaping of the blank by atomizing a suspension. 7. The method according to claim 6 for pressure forming at forming temperatures of 20 to 400 ⁰ C, characterized in that a suspension of the following composition in mass%: Titanium - 0.026 to 0.052 Gallium - 2.5 to 5 aluminum 10 to 20 Mineral oil - remainder
is used. 8. The method according to claim 1 to 5, characterized in that on the coating directly a lubricant is applied prior to plastic deformation. 9. The method according to claim 1 to 5 and 8 for production of products by plastic deformation and separation, characterized in that the separation processes be carried out in the melted state of the coating material. 10. The method according to claim 1 to 5 and 8 for production of products through multi-stage deformation with surface hardening, , characterized in that the surface consolidation on the final send forming stage is carried out, the ratio of the forming speeds of the metal coating on Edge and in the middle of the contact zones of the blank with the tool (in the superplastic state of the coating in of the forming zone) is less than the ratio of the values of the Deformation resistance of the blank material and the Coating material is in the superplastic state of the coating material.