RU2509621C1 - Die block for angular moulding - Google Patents

Abstract

FIELD: process engineering.

SUBSTANCE: invention relates to metal forming and can be used for production of articles with high mechanical properties by forming fine-grain and homogeneous structure. This die block comprises band, male die and female die. Female die has parallel inlet and outlet channels. Said channels feature geometrically identical cross-sections and are interconnected by intermediate channels. Intermediate channel is arranged at the angle of 120°≤θ≤135° to inlet and outlet channels. Intermediate channel cross-section over its entire length in the plane perpendicular to axes of said inlet and outlet channels geometrically identical to cross-section of said channels.

EFFECT: high mechanical properties by forming fine-grain and homogeneous structure.

5 dwg, 1 tbl

Description

The invention relates to the field of pressure treatment of metals and alloys, mainly aluminum, copper, titanium, and is intended to obtain products with improved mechanical properties due to more intense fragmentation of structures with the formation of a fine-grained, uniform structure of the material of the products.

The prior art device for equal channel angular pressing in the form of a matrix made with three intersecting channels. In the process of implementing this method, the workpiece is subjected to shear deformation by moving along an intermediate channel, the shape of which is geometrically identical to the shape of the receiving and output channels (RU 2181314 C2, 04.20.2002).

A disadvantage of the known device is the low intensity of structure formation, insufficient homogeneity of the resulting structures.

Along with this, there is a known device for pressing with a tapering section of the matrix in the form of a ledge in the center of a single channel (Greshnov V.M. “Some structural schemes of forging and pressing equipment for new technological processes of metal forming”, collection of scientific works of the Congress “Kuznets-2008” ":" The state, problems and prospects of the development of forge-and-press machine building, - forging and stamping production and metal processing, are the foundations of the machine-building complex and the national security of Russia ", Ryazan, OJSC TYAZHPRESSMASH, 2008, p.176-180).

A disadvantage of the known device is the limited application for the study of the structure of large ingots with their subsequent use as blanks for stamping or rolling to obtain industrial metal; development of compacts from powders to reduce residual porosity. In both cases, the intensity of the study of structures is low.

The closest solution known from the prior art in terms of technical nature and purpose with respect to the proposed one is a stamp for equal channel angular pressing, containing a bandage, punch and die, with at least three intersecting receiving, intermediate and output channels. The receiving and output channels have identical square sections. The intermediate channel is made screw (RU 2440210 C1, 01/20/2012).

The disadvantages of this stamp include the lack of additionally created compression strains in the intermediate channel and tensile strains at the outlet of the intermediate channel, which significantly affect the strain accumulation rate, and, therefore, additional refinement of the structure.

The technical result achieved by the implementation of the claimed invention is to increase the intensity of the formation of a fine-grained structure and the level of mechanical characteristics of the material of the products by creating additional compressive and tensile stresses when the metal flows through the intermediate channel. Due to this, additional strains accumulate in the metal, which contribute not only to an increase in mechanical properties, but also to a more uniform structure.

The specified technical result is achieved by the fact that, due to the fact that the stamp for angular pressing contains a bandage, a punch and a matrix with receiving and output channels located parallel and made in cross section geometrically identical, interconnected by an intermediate channel at an angle θ, according to the invention, an intermediate channel made in such a way that the cross section along its entire length, in a plane perpendicular to the axes of the receiving and output channels, is geometrically identical to the cross section of the receiving and output channels, wherein the angle is 120 ° ≤θ≤135 °.

- коэффициент, зависящий от угла пересечения каналов θ). Необходимость введенных ограничений по углу пересечения каналов объясняется следующим. Из уровня техники известно, что при геометрической идентичности поперечного сечения всех каналов и углах 90°≤θ≤120° происходит наиболее интенсивное измельчение структуры, также при углах θ>110° обеспечивается отсутствие жестких зон. Однако при реализации заявленного изобретения при углах θ<120° размер b промежуточного канала уменьшается более чем на 50%, что существенно затрудняет течение металла, а при углах θ>135° деформации простого сдвига изменяются на изгиб, при котором измельчение структуры незначительно или отсутствует.Sections in the plane perpendicular to the axis of the intermediate channel are reduced to a size b = a × k in height (a is a parameter that determines the width of the receiving and output channels; $$k=\mathrm{one}-2{\mathrm{<figure-callout\; id="2"\; label="cos"\; filenames="00000007.png,00000008.png"\; state="\{\{state\}\}">cos</figure-callout>}}^2\frac{\mathrm{<figure-callout\; id="2"\; label="\theta "\; filenames="00000007.png,00000008.png"\; state="\{\{state\}\}">\theta </figure-callout>}}{2}$$

is a coefficient depending on the angle of intersection of the channels θ). The need for the introduced restrictions on the angle of intersection of the channels is explained by the following. It is known from the prior art that with a geometric identity of the cross section of all channels and angles of 90 ° ≤θ≤120 °, the most intensive refinement of the structure occurs, and at angles θ> 110 ° there is no hard zones. However, when implementing the claimed invention at angles θ <120 °, the size b of the intermediate channel decreases by more than 50%, which significantly complicates the flow of metal, and at angles θ> 135 ° the simple shear deformations change into bending, at which the structure is crushed slightly or is absent.

для ограничения длины промежуточного канала, что снижает силы трения при прохождении заготовки. Матрица выполнена составной.For the center distance S of the receiving and output channels, it is advisable to assign values in the range $$\frac{a}{2}\le S\le 2a$$

to limit the length of the intermediate channel, which reduces the friction forces during the passage of the workpiece. The matrix is made composite.

The invention is illustrated by graphic materials, where:

- figure 1 schematically shows a stamp for angular pressing;

- figure 2 shows a 3-D channel model of the matrix;

- figure 3 - three intersecting channel matrix with the main parameters;

- figure 4 is a section aa of the intermediate channel;

- figure 5 is a cross section bB of the intermediate channel.

- коэффициент, зависящий от угла пересечения каналов θ).The claimed stamp contains a band 1 (see FIG. 1), into which two half-matrices 2 and 3 are pressed in. The half-matrices have a receiving channel 4, an intermediate channel 5 and an output channel 6. The receiving and output channels (4 and 6) are arranged in parallel and are made in cross section geometrically identical. The intermediate channel 5, connecting the receiving and output channels (4 and 6) at an angle of 9, is made in such a way that the section AA (see Fig. 4) along its entire length in a plane perpendicular to the axes of the receiving and output channels (4 and 6) remains geometrically identical to the cross section of the receiving and output channels (4 and 6). Section B-B (see FIG. 5) in a plane perpendicular to the axis of the intermediate channel 5 decreases to a size b = a × k in height (a is a parameter that determines the width of the receiving and output channels; $$k=\mathrm{one}-2{\mathrm{<figure-callout\; id="2"\; label="cos"\; filenames="00000007.png,00000008.png"\; state="\{\{state\}\}">cos</figure-callout>}}^2\frac{\mathrm{<figure-callout\; id="2"\; label="\theta "\; filenames="00000007.png,00000008.png"\; state="\{\{state\}\}">\theta </figure-callout>}}{2}$$

is a coefficient depending on the angle of intersection of the channels θ).

A blank 7 of the necessary alloy is installed in the receiving channel 4, the height of which is L1 (see Fig. 1), and is pushed by the punch 8 into the intermediate channel 5. The half-matrices 2 and 3 are fixed relative to each other by pins 9. The bandage 1 is asymmetric in order to ensure alignment applied load and axis of symmetry of the stamp. The punch 8 is made so that its cross section is identical to the cross section of the receiving channel 4.

The claimed stamp for angular combined pressing works as follows.

A layer of process lubricant is applied to the surface of the metal billet 7 with a height of (0.7-0.8) × L1 and to the working surface of the punch 8. Then, the preform 7 with the applied technological lubricant is placed in the receiving channel 4 until its lower end comes into contact with the intersection of the receiving and intermediate channels (4 and 5). After that, the punch 8 is introduced into the receiving channel 4 until it touches the upper end of the initial workpiece 7. The deformation occurs by gradually pushing the workpiece 7 with the punch 8 into the intermediate channel 5. When the metal flows through the intermediate channel 5, the workpiece 7 undergoes additional compression deformations. For the subsequent pressing of the workpiece 7 into the output channel 6, the following workpiece (not shown) is used, identical to the workpiece 7. Moreover, each workpiece experiences two simple shear deformation cycles, namely, when the workpiece 7 enters from the receiving channel 4 into the intermediate channel 5 and metal flowing from the intermediate channel 5 to the output channel 6, as well as additional compression and tensile strains when extruding the workpiece 7 through the intermediate channel 8, in which the cross section of the workpiece 7 in one direction is first reduced up to size b, and upon further pushing through the output channel 5, the workpiece 7 acquires the initial dimensions of the cross section a. The filling of the output channel 6 with metal displaced from the intermediate channel 5 occurs due to backpressure created from the side of the previous workpiece in the matrix by contact friction forces and is accompanied by the message to the workpiece 7 of additional tensile deformation.

Thus, the product undergoes two acts of deformation by simple shear and two additional acts of alternating deformation of compression and tension, which increases the rate of formation of the fine-grained structure of the workpiece metal, and also increases the uniformity of the resulting structures and, as a result, increases the mechanical characteristics of the material.

Table 1 describes the specific values of the angle of intersection of the channels 9 from the adopted range, the corresponding values of the coefficient k, the percentage reduction in the size of the intermediate channel compared to parameter a, and the percentage increase in fine grain and uniformity of the resulting structure.

Table 1 Channel crossing angle Coefficient Channel Reduction Improving fine-grained and uniform structure θ k % % degree radian 120 2,094 0,500 50,0 20-25 125 2,182 0.574 42.6 15-20 130 2,269 0.643 35.7 10-17 135 2,356 0.707 29.3 7-12

From the foregoing, it follows that the set of essential features reflected in the claims provides the claimed technical result - an increase in the fragmentation intensity of structures, the homogeneity of the resulting structures while increasing mechanical characteristics.

The analysis of the claimed technical solution for compliance with the conditions of patentability showed that the characteristics indicated in the formula are essential and interconnected with the formation of a stable population unknown at the priority date from the prior art, the necessary features sufficient to obtain the required synergistic (over-total) technical result.

Thus, the above information indicates the fulfillment of the following set of conditions when using the claimed technical solution:

- an object embodying the claimed technical solution, when implemented, is intended for pressure treatment of metals and alloys, mainly aluminum, copper, titanium, and is intended to produce products with improved mechanical properties due to more intense fragmentation of structures with the formation of a fine-grained, homogeneous structure of the product material;

- for the claimed object in the form described in the formula, the possibility of its implementation using the methods and methods described above or known from the prior art on the priority date is confirmed;

- the object embodying the claimed technical solution, when implemented, is able to ensure the achievement of the technical result perceived by the applicant.

Therefore, the claimed subject matter meets the requirements of the patentability conditions of “novelty”, “inventive step” and “industrial applicability” under applicable law.

Claims (1)

A stamp for angular pressing, containing a bandage, a punch and a matrix with parallel receiving and output channels, which are made with geometrically identical cross sections and interconnected by an intermediate channel located at an angle of inclination θ to the receiving and output channels, characterized in that the intermediate channel along the entire length is made with a cross section in a plane perpendicular to the axes of the receiving and output channels, geometrically identical to the cross section of the said receiving and output channels in, the inclination angle θ of the intermediate channel is 120 ° ≤ θ ≤ 135 °.

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