CS243374B1 - Method for compacting powder materials - Google Patents

Abstract

Method of compacting powder materials by explosive compression. The essence of the invention is that before compaction, the powder materials are placed in protective packaging or linings of the cavities of the die body, which are made of metals or alloys whose melting point is lower than the temperature range of the structure of the powder materials, and after the explosive operation, the molding is printed by melting the packaging or liner.

Description

The invention relates to a method of compacting powder materials by means of explosion pressing.

The method of explosion pressing of powdered materials is generally known and its advantage lies primarily in the ability to apply pressures whose values exceed by several orders of magnitude the pressures used in static presses.

It is possible to compress 1 particularly hard powder materials into compact bodies, the density of which is close to the theoretical density, and whose total volume of the cutter is substantially higher than that of static devices.

A disadvantage of the prior art explosion pressing methods is that the powder materials must be placed in protective, usually steel (die) housings during the explosion operation, which protect them from the immediate effect of gaseous products detonating charges.

After the blasting operation, the molding with the die forms a non-demountable unit, the molding being recovered by the most frequent mechanical machining !, which is an operation which is time-consuming and energy-consuming, and can be damaged during it.

The disadvantages of the present invention are eliminated by the method of shutting down powdered materials by explosive pressing according to the invention, which consists in that before compacting the powdered materials are placed in protective sheaths or liners of die bodies which are made of metals or alloys whose melting point is lower than a change in the structure of the powdered materials, after which the molding is obtained by melting the packaging or moulder after the explosion operation.

An advantage of the method according to the invention is that it is easy to remove the moldings from the tool, in that after the explosion operation the die is heated above the melting temperature of the lining material, thereby releasing the molding from the cavity.

This eliminates any mechanical processing to obtain the moldings, since they do not form a non-disassembling unit with the die. The method can be advantageously used to compress various metal and non-metal powders or mixtures thereof. The Assembly Arrangement option can be used to produce a simple and most complex shape application.

1 and 2 show exemplary embodiments of explosive shuttering powder assemblies.

Fig. 1 shows a plane shock wave compression assembly. In a prism-shaped steel body 6, a cavity is formed, the walls of which are covered with a lining g of low-melting metal or alloy.

The cavity is filled with a pressed powder 6 which is covered with a steel protective plate 6. Placed thereon is a toroidal charge, which is initiated by the detonator 1 via a plane detonator face generator X, so that the detonation wave advances perpendicularly to the die face.

FIG. 2 shows the aeatava for cylindrical symmetrical loads. The base body of the die is shot with a stainless steel tube g, the inner wall of which is covered with a liner g of a non-fusible metal or alloy and both ends are closed with plugs g.

The inner proator is filled with pressed powder 6. This die is surrounded by a hollow cylinder-shaped explosive charge g initiated by a detonator g. The detonation wave front extends in the direction of the axis.

After the explosion operation, the die is heated above the melting point of the lining material, thereby releasing the molded part with the hips. The method can be advantageously used for pressing various metal /

And non-metallic powders 81 mixtures thereof. The lining material must be selected such that the melting point is lower than the structural transformation temperature of the molded materials, e.g., their melting point or the temperature at which the crystalline modification changes.

Depending on the assemblies shown in Figures 1 and 2, moldings in the form of platelets or rods are obtained, but in other configurations or other cavity shapes moldings of other and more complex shapes can be produced.

A specific embodiment of the explosion molding according to the invention is shown in the following examples.

Example 1

In a steel prism of 200 x 200 x 100 aa, a square-shaped cavity with a 120 m edge length and a depth of 20 on the top square is drawn concentrically.

The walls of this cavity are covered with a lining of Vood metal in a thickness of 3 mm.

The cavity is filled with an omega-thick layer of partially oxidized aluminum slurry having an AlgO ≥ 13% content with an average particle size of 50 / ba and a relative density of 50%. The powder layer is covered with a steel plate of thickness 7a and 114 x 114 aa.

Adjacent to it is an explosive charge of square cross section with an edge of 160 µm and a height of 40 mm, the bottom of the charge consists of a steel sheet thickness of 3 mm. The explosive, whose detonation pressure is 5 QPa, is initiated by a planar detonation face generator.

After the explosion operation, the plate is heated above the melting point of the Vood metal, thereby releasing a 114 x 114 mm plate-shaped molding and about 5 mm thickness. The relative density of the compact is higher than 95% of theoretical.

Example 2

In a steel cylinder of ø, 60 aa and a height of 120 mm, a cavity of i 106 mm and a depth of 26 aa is formed on the front face of the component. This cavity is provided with a lining of ZnA14CuO5 alloy in 3 dew thickness and filled with a hoaogenised mixture of tungsten and copper powders (V: Cu weight ratio> 9: 1) to a height of 15 aa.

The relative density of the mixture is 40% theoretical. The powder layer is covered with a steel plate of 100 m thickness and 7 aa thickness. Adjacent thereto is a cylindrical explosive charge of mm, 20 mm and a height of 50 aa, filled into a plastic container.

The bottom of the charge consists of steel sheet thickness 4aa. The detonation pressure of the explosive used is 2 QPa and its initiation is carried out by a plane detonation face generator. After the explosion operation, the body is heated above the melting point of the zinc alloy forming the lining of the cavity, thereby releasing a circular plate molding of about 100 aa, a height of about 6.5 aa and a relative density greater than 90% of theoretical.

Example 1

X 32 x 3 mm long, 300 aa stainless steel tube filled with a non-squealing alloy of 70 X Pb, 20 X Sb, 0 X Sa. An axial cavity of 16 aa, 260 mm long is left in the axis, filled ae with a length of 220 mm by a powder mixture of cubic boron nitride and cobalt (9: 1 weight ratio) at a relative density of 65 X.

The filler is closed in a cavity with a steel plug and encloses concentrically with an explosive charge with an outer diameter of 90 mm and a length of 320 mm. The explosive, which has my detonation pressure of 8 QPa, is initiated by an industrial detonator in the center of the upper surface.

After the blasting operation, the tube is heated above the melting point of the lining, releasing the molding in the shape of about 13 at a distance of 220 m and a relative density of greater than 90%.

Claims (1)

Explosion compaction method of powdered materials · marked by t, la before shutdown, powdered materials are placed in protective shells or lining of die cavities of the die body which are shot and of metals or alloys whose melting point is lower than the temperature change of the powdered material ee sieve molding by melting the packaging or liner.