SU1337195A1 - Apparatus for extruding elongated articles from powder - Google Patents

Abstract

The invention relates to devices for extruding long articles from powder. The goal is to reduce the force of extrusion and improve the quality of products. The powder is fed to container 2, compacted with punch 1 and extruded through the matrix 3 and non-. Vizny calibrating element 4 matrix. During the extrusion process, the die 3 is driven into rotation by a chain drive 6 Due to the absence of friction of the extruded powder against the working surface of the rotating die, the extrusion force is significantly reduced. By using a fixed gauge element, the quality of the product increases. When pressing long aluminum products, the extrusion force decreases from 8.8 kN (known device) to 5.5 kN (described device). 1 hp ff, 3 ill. (Л 13 ff со со со со со фе.1

Description

The invention relates to powder metallurgy, in particular, to the manufacture of long products by the manufacture of metal powders and granules.

The aim of the invention is to reduce the force of extrusion and improve the quality of products.

Fig, 1 shows a diagram of the device section; in fig. 2 - matrix; in fig. node I in FIG. 2

The device comprises a punch 1, a container 2, a die 3, mounted rotatably. At the output of the matrix 3, its fixed support element 4 is located. The matrix 3 is rigidly connected by I; gear ring 5, which, in turn, is connected by means of a chain transmission 6 with a leading sprocket 7. The latter is rigidly connected to the drive shaft 8. The punch 1 is rigidly connected to the upper plate 9 of the press, and the container 2 is installed in the intermediate plate 10. . The movable matrix calibrating element 4 is mounted on the bottom plate 11. Plates 9-11 are connected by columns 12 and 13, Matrix 3 is made with a helical groove 14 on the working surface, and the step of the said groove does not exceed 0.85 of a smaller diameter of the working surface of the matrix 3.

Figs 1 and 2 depict a conical working surface with the largest diameter D, the smallest d, d being the diameter of the working surface of the matrix in an arbitrary cross section at a distance Z from the upper end surface of the matrix, H being the height. The angle of inclination of the generatrix of the working surface to the vertical axis of the matrix has limits. The pitch of the helical groove 14 cannot exceed 0.85 of the smaller diameter of the working surface of the matrix, since otherwise the peripheral

The lei of the material being injected is rotated into rotation, which leads to additional energy costs for overcoming a decrease in interparticle friction in the material being injected and, as a result, to an increase in the force of extrusion.

To ensure the best quality of the surface of the extruded billet, the screw groove is not cut to the end of the die outlet, because otherwise the surface of the billet is

copy of the working screw surface of the matrix.

Maximum reduction of the extrusion force. It is possible with equal velocities of the peripheral and central layers of the extruded material over the entire working surface of the die. In the case of a difference in the speeds of movement of the peripheral and central layers of the extruded powder, the extrusion force increases due to the presence of interparticle friction in the extruded material.

To ensure that the velocities of the peripheral and central layers of the extruded material are equal, the pitch of the helical groove should be variable and determined as follows

 0.85 d (D - 2H tga) H (D - 2 Z tg (U) 2

where D and d are the largest and smallest diameters of the working surface of the matrix, respectively;

H is the height of the matrix; angle of inclination

the working surface of the matrix is 2–1 to its axis; Z 2 distance from top

t. end surface of the matrix to its arbitrary cross section; the step size of the helical groove preceding the one defined.

The device works as follows.

The powder is fed into the container 2, compacted with the punch 1 and extruded through the matrix 3 into the stationary calibrating element 4 of the matrix. In the extrusion process, the die 3 is rotated by a chain drive 6, with

the rotational speed is chosen from the condition that the translational velocity of the peripheral powder layers is equal by the helical groove of the working surface of the rotating matrix 3 and

punch speeds 1. In this case, the peripheral layers of the extruded material are entrained by the helical groove and are forced to move in the extrusion direction. Due to lack of time3

Because of the friction of the extruded powder against the working surface of the rotating matrix 3, the extrusion force is significantly reduced and is determined only by the degree of compaction of the extruded material and by the forces of friction as the material passes through the fixed calibrating element 4 of the matrix. At the outlet of the calibrating element, products of circular cross section of various lengths are obtained, determined by the dimensions of the container 2 and the ratio of the diameters of the punch 1 and the fixed calibrating element 4 of the matrix.

Example 1. A matrix was set at an angle of 0/30 ° to extrude into the mold, on the working surface of which a screw groove was made, the profile of which is shown in FIG. 2. The groove pitch is 6 mm and 3 mm.

The quality and density of the blanks in all experiments were the same.

The extrusion of the aluminum-based powder composition in a mold with a smooth conical die was achieved with a force of 10.6. kN. Rotation of the matrix with a frequency of 2s led to a decrease in the force to 8.8 kN.

Extrusion through a rotating matrix, on the working surface of which a screw groove was made, was carried out with a force of 5.5 kN.

The surface of the products obtained by pressing in a smooth conical maritas had captives indicating the setting of aluminum from the tool because of the high contact voltages. The products of the proposed device (from a rotating matrix with a helical groove) had a smooth surface without traces of the helical groove and other defects.

Example 2. Inserting nickel-based powder compositions in which, as a plasticizer, 10% by weight of paraffin was introduced, and on the basis of aluminum, of which plasticizer is one of the components of the composition — a thiokol (12% by weight).

The extrusion of these powder compositions was carried out in the mold shown in FIG. 1. The diameter of the puzon (the cavity of the matrix) of the mold is 25 mm, the angle of inclination of the walls of the working surface of the matrix in all variants is uf 30, the diameter of the caliper is 954

holes (extruded product) d 10 mm.

For the experiments, a universal hydraulic press UIM-50 was used, the speed of movement of the press beam in all cases of 10 mm / s.

When the powder composition based on nickel was pressed into the mold with the smooth conical working cavity of the matrix without rotating it, the force was 7.1 kN. The use of the proposed device reduced the extrusion force to 5.8 kN.

The device allows to obtain products from hard-to-deform materials, in particular, products from various powders without using plasticizers, which ensures a higher quality of the product after sintering.

Thus, the use of the proposed device allows to significantly reduce the force of extrusion of products from metal powders and granules granules when round products are obtained, which makes it possible to use less powerful equipment to obtain the same sizes of products and also to improve the quality of the products obtained.

Claims (2)

1. A device for extruding long products from powder, including a punch, a container and a matrix with a conical working surface, mounted rotatably, characterized in that, in order to reduce the force of pressing and increasing the quality of the products, it is provided with a calibrating element fixed under the die, and the matrix is made with a screw groove; on the working surface, and the groove pitch does not exceed 0.85 smaller diameter of the working surface of the matrix. 2. The device according to claim 1, characterized in that the pitch of the helical groove is determined from the dependence   d (D - 2H tg o) 2 (D - 22): g where D and d are the largest and smallest diameters of the working surface51337195 matrix matrices, respectively; 2-1 l one T t | - distance from upper  ° end surface of the matrix to its arbitrary cross section; 6 - screw tag value grooves preceding the definable - matrix height; - the angle of inclination of the generatrix of the working surface of the matrix to its axis. (pus.2 8 (ff, -0, FIG. 3 Compiled by I. Kinsky Editor N. Slobod nickname Tehred L. Oliynyk Proofreader N. Korol 4079/12 Circulation 740 Subscription VNIIPI USSR State Committee for inventions and discoveries 113035, Moscow, Zh-35, Raushsk nab., 4/5 Production and printing company, Uzhgorod, st. Project, 4