SU1289602A1 - Method of producing articles of plastified powders - Google Patents

Abstract

This invention relates to methods for making articles from plasticized powders. The purpose of the invention is the complexity of the process of manufacturing large-sized products. 50 vol% paraffin at 80 ° C is introduced into the powder of the hard alloy VK6 by stirring in a mechanical mixer. The mixture is mixed in the mixer by forcing through the lattice, and then in the mold by the repeated action of alternately ring and core punches. After mixing with the same punches, the product is molded. The reduction in the laboriousness of the process of manufacturing large-sized products is achieved by the fact that after mixing by pressing, the mixing in the mold is carried out additionally by creating alternate pressure in the longitudinal direction to different parts of the mixture. 3 il. e (lu 00

Description

one .

The invention relates to powder metallurgy, in particular, to a method for manufacturing products from plasticized mixtures in a confined space.

The purpose of the invention is to reduce the labor intensity of the process of manufacturing large-sized products.

The method is carried out as follows.

A plasticized mixture of fine powders of c50 ± 5 vol.% Is prepared. thermoplastic plasticizer at the temperature of its liquid state by manual mixing or using mechanical agitators. After the introduction of a plasticizer, the resulting composition is mixed by repeatedly smashing plasticized powder mixtures through a closed space of a mixing mechanism until the initial shape of the mixture is obtained, and the mixture is plastically deformed with changes in all sizes. Then a periodic effect of pressure on one or the other part of the mixture creates its constant movement in one or the other direction, i.e. creates a constant movement of the layers relative to each other. In addition, the mixture also moves in the direction of the applied pressure, creating mixing of the layers of the mixture. As a result of repeated repetition of mixing cycles, the plasticized mixture is homogeneous throughout the volume, since the plasticizer contains 50% by volume, the mixture is able to flow easily under the applied pressure and uniformly fill any complex volume at the plasticizer plastic state temperature.

Mixing by applying a periodically applied pressure to different parts of the volume of the mixture is carried out in the cavity of the mold.

Fig. 1 shows a diagram of one-sided mixing by two movable punches; Fig. 2 is a two-sided mixing scheme of four movable punches; FIG. 3 is an annular and rod mixing scheme, punches.

It is also possible to perform the blending.

25

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, punches, subject to their periodic effect on different parts of the stirred mixture; whereby both longitudinal and

5 and the transverse displacement of the layers of the mixture and the mixture becomes homogeneous throughout the volume.

The mixture is pressed in the same mold.

0 Example. To manufacture a complex part such as a ring with chamfers and a shaped end, 50 vol% paraffin of paraffin is mixed into the powder of the hard alloy VK6

 mechanical stirrer. Plasticized the bath mixture is mixed in the mixer by forcing through the lattice, and then in the mold by repeated action of the alternate ring and

20 rod punches.

After mixing is completed, a briquette is formed by the same punches, from which a tubular billet is formed by a backward extrusion method, followed by cutting the ring of an approximate billet.

From the annular piece billet thus obtained in a closed form, which repeats the configuration of the part, the billet pressure for sintering, i.e. ring with chamfers and shaped end with dimensions that take into account shrinkage during sintering. When forming blanks take into account

35 the possibility of air release and lichen by volume of the moldable mass through special slotted gaps in the mold. After molding, the formed burr is removed.

40 Stirring and shaping operations are carried out at 40 ° C. Next, pre-preliminary sintering is carried out in hydrogen medium by heating the blanks to 1000-1100 ° C, and

45 1 h and cooled.

The final sintering is carried out in a vacuum furnace at 1380-1460 ° C to obtain blanks with a carbon content of at least 5.76% and oxygen

50 not more than Oh, 1%.

As a result of all operations, a ring with chamfers and a shaped girder with exact dimensions is obtained. To manufacture a glass type part with a wall thickness of 5 mm, 50 vol% paraffin was introduced into the iron powder containing 2% copper with mixing in a mechanical mold

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shalke. The plasticized mixture was mixed in a mixer by forcing through a lattice, and then in a mold by the repeated action of alternately annular and core punches. Then, the same punches were used to form a briquette, from which the approximate billet of the glass was molded by the method of reverse extrusion.

From the obtained billet in a closed form that repeats the configuration of the part, the billet was molded under pressure by sintering.

The implementation of mixing by forcing the mixture through the spinnerets of the mixing mechanism and alternately applying pressure on various parts of the mixture volume eliminates the operation of hydrostatic reduction and mechanical treatment, thereby reducing the laboriousness of the process of making sintered products 896024

The LII of a complex shape, in addition, the application of the proposed technical solution makes it possible to obtain parts of complex spatial shape and large dimensions.

Claims (1)

Invention Formula The method of manufacturing products from plasticized powders, including mixing in a closed volume of the mixture by pushing it through dies and pressing into a press, characterized in 5 in order to reduce the complexity of the process of manufacturing large-sized products, after mixing mixing in a mold by creating alternate pressure in the longitudinal direction to different parts of the mixture. i W / 77U S t I . I eleven /////. Fi.e