Method and plant for producing extrusion billets

Abstract

A method and a system produces extrusion billets from scraps obtained from stamping, cutting and/or machining operations, in particular scraps made of magnesium or magnesium alloys, without subjecting these to a melting process. The system for carrying out the method is essentially composed of a storage unit for the scraps, a device for comminuting the scraps, a press for producing a round briquette, and an extruder for shaping the round briquette into a extrusion billet.

Claims

1. A method for producing profiles from magnesium or magnesium alloy scraps obtained from stamping, cutting and/or machining operations, comprising: removing the scraps from a storage unit; filling a round compression mold with the scraps; compressing the scraps to obtain a round briquette having a density of greater than 60%; heating the round briquette in a furnace to a temperature above 250 C.; introducing the heated round briquette into an extruder and, under pressure, extruding the round briquette through a first die into an extrusion billet having a density of greater than 95%, wherein the round briquette is deflected one or several times under the action of a pressing force and formed into the extrusion billet; cutting the extrusion billet; homogenizing the extrusion billet at a temperature above 400 C. for a predetermined time period; and extruding the extrusion billet through a second die into a profile.

2. The method according to claim 1, further comprising comminuting the scraps before filling the round compression mold with the scraps prior to filling the round compression mold.

3. A system for producing profiles from magnesium or magnesium alloy scraps obtained from stamping, cutting and/or machining operations comprising, in the following order, a storage unit for the scraps, a cutter for comminuting the scraps, a press for producing round briquettes, a furnace for heating the round briquettes, an extruder for extruding extrusion billets from the round briquettes, the extruder being configured to deflect the round briquettes one or several times under the action of a pressing force, and a second extruder for extruding the extrusion billets into profiles.

4. The system according to claim 3, wherein the cutting device for comminuting the scraps is disposed between the storage unit and the press.

5. The system according to claim 3, wherein the press comprises at least one vertical round compression mold.

6. The system according to claim 4, wherein the press comprises at least one vertical round compression mold.

Description

BRIEF DESCRIPTION OF THE DRAWING

(1) The drawing shows a schematic of the system according to the invention.

DETAILED DESCRIPTION OF THE INVENTION

(2) The drawing shows a schematic of the system according to the invention for producing extrusion billets 6. This system is essentially composed of a storage unit for the scrap material from ongoing production. Since one and the same material, this being a magnesium alloy, and preferably an alloy with the designation MnE21, is used for the entire production, the scrap material is also pure scrap.

(3) The scraps are accommodated in the storage unit 1 separated according to the geometric dimensions thereof. Scraps having a smaller grain size, for example from machining, can be delivered directly into the press 3. Scraps having larger geometric dimensions, for example stamping scraps or clippings, are comminuted into scraps having a suitable grain size by way of a device 2. These can then either be delivered into the press 3 or mixed with other scrap, for example chips.

(4) The press 3 is designed as a mechanical press having a vertical round compression mold. The vertical design simplifies the filling of the compression mold and also enables maximum filling. A compression unit comprising multiple juxtaposed compression molds would also be conceivable. Under the action of a pressing force on the filled-in content of the compression mold, a round briquette having a density of more than 60% is created.

(5) The round briquettes 7 produced are heated in a furnace 4 to a temperature of approximately 450 C. Subsequently, the heated round briquette 7 is introduced into the hopper of the extruder 5 and deformed under application of pressure to obtain an extrusion billet 6 or extrusion billet strand. If an extrusion billet strand is used, it can be cut to the appropriate length after leaving the die, for example by way of a flying saw. The resulting extrusion billet has a density of greater than 95%.

(6) Thereafter, the extrusion billet can be further processed into appropriate profiles 9 in an extruder 8 on the press line or be temporarily stored. Optionally, the extrusion billet can be homogenized at a temperature above 400 C. for a duration of approximately 6 hours.