Classifications

• • C—CHEMISTRY; METALLURGY
  • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
  • C22F—CHANGING THE PHYSICAL STRUCTURE OF NON-FERROUS METALS AND NON-FERROUS ALLOYS
  • C22F1/00—Changing the physical structure of non-ferrous metals or alloys by heat treatment or by hot or cold working
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
  • B21C—MANUFACTURE OF METAL SHEETS, WIRE, RODS, TUBES OR PROFILES, OTHERWISE THAN BY ROLLING; AUXILIARY OPERATIONS USED IN CONNECTION WITH METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL
  • B21C23/00—Extruding metal; Impact extrusion
  • B21C23/001—Extruding metal; Impact extrusion to improve the material properties, e.g. lateral extrusion
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
  • B21C—MANUFACTURE OF METAL SHEETS, WIRE, RODS, TUBES OR PROFILES, OTHERWISE THAN BY ROLLING; AUXILIARY OPERATIONS USED IN CONNECTION WITH METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL
  • B21C23/00—Extruding metal; Impact extrusion
  • B21C23/02—Making uncoated products
  • B21C23/20—Making uncoated products by backward extrusion
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
  • B21C—MANUFACTURE OF METAL SHEETS, WIRE, RODS, TUBES OR PROFILES, OTHERWISE THAN BY ROLLING; AUXILIARY OPERATIONS USED IN CONNECTION WITH METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL
  • B21C23/00—Extruding metal; Impact extrusion
  • B21C23/21—Presses specially adapted for extruding metal
  • B21C23/218—Indirect extrusion presses
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
  • B21C—MANUFACTURE OF METAL SHEETS, WIRE, RODS, TUBES OR PROFILES, OTHERWISE THAN BY ROLLING; AUXILIARY OPERATIONS USED IN CONNECTION WITH METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL
  • B21C25/00—Profiling tools for metal extruding
  • B21C25/08—Dies or mandrels with section variable during extruding, e.g. for making tapered work; Controlling variation
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
  • B21J—FORGING; HAMMERING; PRESSING METAL; RIVETING; FORGE FURNACES
  • B21J1/00—Preparing metal stock or similar ancillary operations prior, during or post forging, e.g. heating or cooling
  • B21J1/02—Preliminary treatment of metal stock without particular shaping, e.g. salvaging segregated zones, forging or pressing in the rough
  • B21J1/025—Preliminary treatment of metal stock without particular shaping, e.g. salvaging segregated zones, forging or pressing in the rough affecting grain orientation
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
  • B21J—FORGING; HAMMERING; PRESSING METAL; RIVETING; FORGE FURNACES
  • B21J5/00—Methods for forging, hammering, or pressing; Special equipment or accessories therefor
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
  • B21J—FORGING; HAMMERING; PRESSING METAL; RIVETING; FORGE FURNACES
  • B21J5/00—Methods for forging, hammering, or pressing; Special equipment or accessories therefor
  • B21J5/008—Incremental forging
• • C—CHEMISTRY; METALLURGY
  • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
  • C22F—CHANGING THE PHYSICAL STRUCTURE OF NON-FERROUS METALS AND NON-FERROUS ALLOYS
  • C22F1/00—Changing the physical structure of non-ferrous metals or alloys by heat treatment or by hot or cold working
  • C22F1/06—Changing the physical structure of non-ferrous metals or alloys by heat treatment or by hot or cold working of magnesium or alloys based thereon

Definitions

• the invention relates to a method for producing metal alloys, in particular magnesium alloys, with small grain sizes within a non-extruded metal alloy body and to an apparatus for carrying out the method.
• the use of light metal materials primarily serves to reduce the weight of the components used.
• the use of prefabricated bodies made of light metal materials e.g. Aluminum, metal and titanium alloys, but especially prepares for further processing such as when rolling, forging or rolling, production problems, since due to the mostly large grain sizes of the starting materials, cracks and breaks usually occur along the grain boundaries at the corners of the body made of light metal materials. This influences and reduces the mechanical and optical properties of the components.
• DE 199 37 184 A1 relates e.g. a metal alloy for use at elevated temperatures, which is particularly suitable for use in the die casting process.
• the disadvantage here is that previously known and frequently used light metal alloys cannot be used and that a special light metal alloy would have to be developed for each application and each application method.
• DE 199 17 175 A1 describes a method for producing a component and the component according to the invention.
• the component is produced in a die-casting mold by means of a ceramic green body in the die-casting mold by filling this green body with a metal or a metal alloy, the green body being produced as a ceramic base body by means of a ceramic powder mixture using a heating and pressing process.
• the disadvantage here is that this process can only be used in the die casting process.
• DE 100 33 768 A1 describes a method for folding thin-walled semi-finished products or components made of at least one metallic material, the material being difficult or brittle to deform at room temperature and being heated in the region to be folded.
• the disadvantage here is that the brittleness properties of the metal materials being processed are not changed during the folding and therefore the components are still susceptible to breakage and cracking in subsequent production stages.
• the disadvantage here is that the change in the structure depends on the recrystallization rate within the blank and can therefore only be used to a limited extent in the course of a processing and manufacturing process.
• DE 695 05 327 T2 describes a method for producing a localized fine-decimal microstructure on selected surfaces made of aluminum alloys.
• the surface of an aluminum sheet with a coarse grain microstructure with long grain boundaries lying generally parallel to the longitudinal plane is characterized by Machining spherical fins locally within existing bores by breaking up the coarse-grained microstructure and then initiating recrystallization by localized heat treatment.
• the disadvantage here is that the method can only be used for drilling within an aluminum alloy of an aircraft sheet.
• the depth of deformation of this process into the surface is only very small, so that it merely prevents the surface corrosion of the treated surfaces, but does not prevent cracking and cracking during rolling.
• the surfaces of a non-extruded metal alloy body with a grain size greater than 200 / m are alternately locally compressed and alternately by a cyclic, location-dependent alternating loading of the surface of the non-extruded metal alloy body decompressed, and permanently heated to a process temperature range of up to 600 ° C.
• the cyclical, location-dependent, alternating loading of the surface of the metal alloy body takes place by temporary pressure by means of pressure-exerting elements on individual defined surface segments of the surface of the metal alloy body.
• surface is understood as a surface layer of the metal alloy body which is influenced and changed by the cyclical, location-dependent load.
• the depth of this surface layer is depending on the metal alloy used, the temperature and the rate of deformation of the metal alloy due to the cyclical, location-dependent alternating load along the outer sides of the metal alloy body.
• one of two partial surfaces of the surface segment is first loaded by means of pressure-exerting elements in a first pressing cycle and then the second partial surface of the surface segment is compressed by means of other pressure-exerting elements in a second pressing cycle, the first partial surface not being loaded in the second pressing cycle.
• the shape of the respective surface segment is preferably symmetrical, in particular circular or rectangular.
• the unloaded first partial surface is decompressed due to volumetric forces within the metal alloy body and / or by means of elements that exert tensile stress during the second pressing cycle.
• spring-restoring elements which, as a location-dependent counterforce to the first partial surface, allows control of the height and rate of deformation of the decompressing first partial surface, especially at the beginning of the second pressing cycle. Especially at the beginning of the second pressing cycle, a sudden movement of the decompressing first partial area can occur due to the acting frictional forces, which can negatively influence the material properties of the decompressing first partial area.
• the metal alloy body assumed the initial volume shape as before the two pressing cycles. This press cycle sequence can be carried out as often as desired within a surface segment with a further number of integral press cycles.
• the metal alloy body is heated to a temperature of up to 600 ° C for a period of time if there is a high heat loss rate within the surface segment.
• the shape of the first partial surface is preferably designed as an annular surface or a semicircular surface within the surface segment and the second partial surface corresponds to the first partial surface within the surface segment.
• a multiplicity of surface segments are defined on the surface of the metal alloy body, the surface segments adjoining one another and the surface of the metal alloy body being completely covered with surface segments with respect to at least one orientation.
• a constant temperature is in a temperature range from to within the entire metal alloy body Given 600 ° C. The volume of the metal alloy body is not changed during the process.
• the method is not only applicable to a surface segment on the surface of a metal alloy body, but can successively cyclically and alternately compress and decompress the two partial surfaces of the respective individual surface segments along connected surface segments.
• the two partial surfaces of the individual surface segments along the surface of the metal alloy body can be successively cyclically and simultaneously compressed and decompressed along connected surface segments.
• Several surfaces of the metal alloy body can be successively cyclically compressed or simultaneously compressed and decompressed.
• a pressure-exerting element loads one of two partial surfaces of the surface segment during a first pressing cycle, and then another one for the first precisely fitting, pressure-exerting element is applied to the surface segment with a second partial surface corresponding to the remaining surface and is loaded in a subsequent second press cycle, and a heat source permanently temperature-regulates the metal alloy body to a predetermined process temperature in a range up to 600 ° C.
• the heat source is only necessary, however, if the heat loss rates during the process are too high or the manufacturing process takes too long and there is a corresponding temperature loss of the metal alloy body.
• the surface segment is defined by the inner diameter of a pressure-resistant container parallel to the surface of the metal alloy body.
• the pressure-exerting elements fill the inside diameter of the container accordingly and precisely.
• the cross section of the metal alloy body corresponds to the cross section of the container, the dimensions of the container being determined by the dimensions of the metal alloy body and the machining plants, such as the rolling mill.
• the pressure in the interior of the container is transmitted to one of two partial areas by stamp elements, the stamp elements being controlled by force transmitters connected to an external press. Furthermore, the interior and the surface segment are kept at a process temperature during the process in order to compensate for any temperature losses that may occur.
• a force transmitter actuates the stamp elements alternately and cyclically and transmits the pressure of the press to the respective partial surfaces of the surface segments.
• the force transmitter such as a steel plate
• the force transmitter is relieved by the press and then the pressure is transferred exclusively to the second stamp element via the force transmitter which is reloaded by the press.
• the force transmitter or the steel plate are heated to the process temperature.
• the stamp surface of the first stamp element is in particular designed as an annular surface or as a semicircular surface within the inside diameter of the container.
• the stamp surface of the second stamp element is designed to fit exactly and corresponds to the first stamp surface of the first stamp element within the inside diameter of the container.
• the height of the first stamp element and the height of the metal alloy body taken together have a greater height extension than the container.
• the deformation in the surface of the metal alloy body is determined by varying the respective excess height of the stamp element and of the metal alloy body relative to the container.
• an excessively high height relative to the container leads to instabilities during the pressing cycles and can lead to breakage of the stamp elements.
• the stamp elements are pressed so far into the metal alloy body during a press cycle that the upper edge of the stamp elements coincide with the upper edge of the container.
• a continuous arrangement of containers arranged side by side along the surface of a metal alloy body defines a plurality of surface segments along an orientation of the surface of a metal alloy body.
• a periodic arrangement of first and second stamp elements serves for the cyclical, location-dependent alternating pressing of an elongated metal alloy body and thus influences the grain sizes of certain orientations along the surface of the metal alloy body.
• the respective first and second stamp elements of a surface segment can be controlled individually.
• the first stamp element is activated by a force transmitter and in a two pressing cycle the second stamp element is activated and then a new press cycle is initiated in a surface segment closest to this.
• the grain size of the metal alloy is changed by the device according to the invention along an orientation of the surface. After completing all process cycles, the metal alloy body is removed from the container.
• the grain sizes are reduced only along a selected orientation vertical to the longitudinal axis of the metal alloy body, the orientations of the reduced grain sizes along the surface of the metal alloy body being symmetrical with respect to the longitudinal axis of the metal alloy body and in particular a sandwich structure with respect to the treated and untreated surfaces form the metal alloy body.
• the method of the present application excludes the processing of extruded metal alloys as in DE 195 08 718 A1. It is used to process non-extruded metal alloys with a grain size of more than 200 ⁇ m due to a cyclical, location-dependent alternating load, which leads to local compression and decompression on individually defined surface segments.
• the features of the application differ significantly from the features of DE 195 08 718 A1 by these features. When "kneading" a raw alloy by applying a force from different directions, cyclical, location-dependent loading of the metal alloy, which leads to local compression and decompression, is excluded.
• 1b shows a schematic longitudinal view of the device according to the invention along a periodic arrangement of the entire surface with first stamp elements symmetrical with respect to the central axis;
• FIG. 2b shows a schematic longitudinal view of the device according to the invention along a periodic arrangement of the entire surface with first stamp elements asymmetrical with respect to the central axis;
• Figure 3 is a schematic transverse view of the invention
• Figure 6 is a schematic view of the product according to the invention.
• FIG. 1a shows a schematic illustration of the transverse view of the device according to the invention during three different process sections.
• the metal alloy body 10 is compressed within a container 11 by a first stamp element 12.
• the upwardly oriented surface of the metal alloy body 10 corresponds to a defined surface segment.
• the first stamp element 12 compresses only a part that is symmetrical with respect to the shape of the surface segment.
• the second stamp element 13 is inserted into the remaining intermediate space of the surface segment in a second process section (middle illustration) and pressed into the metal alloy body 10.
• the first stamp element 12 which is not loaded in the second process cycle, has been partially pushed out of the container 11 and the metal alloy body 10 has assumed its initial volume shape.
• the metal alloy body 10 is heated to a predetermined process temperature by a heater (not shown) or the metal alloy body 10 itself has the required process temperature due to preheating (not shown).
• FIG. 1b shows a schematic longitudinal view of the device according to the invention in two different process stages.
• the method according to the invention is carried out within a surface segment A defined by the first stamp element 12 along the surface of the metal alloy body 10, in in which the first stamp element 12 is pressed into the metal alloy body 10 in a first process cycle and the second stamp element 13 is also pressed into the metal alloy body 10 in a second press cycle and the first stamp element 12 is relaxed back unloaded (left illustration).
• the method according to the invention is then applied to the following surface segment B and to the subsequent surface segments along the surface (illustration on the right).
• FIG. 2a shows a schematic representation of the transverse view of the device according to the invention during three different process sections.
• the surface segment of the surface of the metal alloy body is loaded asymmetrically with respect to the central axis of the container 11.
• the metal alloy body 10 is compressed within a container 11 by a first asymmetrical stamp element 12. Only the cross section of the metal alloy body 10 is visible in this schematic illustration.
• the first stamp element 12 compresses only an asymmetrical part of the surface segment.
• the second stamp element 13 is inserted into the remaining intermediate space of the surface segment in a second process section (middle illustration) and pressed into the metal alloy body 10.
• the first stamp element 12 which is not loaded in the second process cycle, has been partially pushed out of the container 11 and the metal alloy body 10 has assumed its initial volume shape.
• the metal alloy body 10 is heated to a predetermined process temperature by a heater (not shown) or the metal alloy body 10 itself has the required process temperature due to preheating (not shown).
• FIG. 2b shows a schematic longitudinal view of the device according to the invention in two different process stages for an asymmetrical variant of the inventive arrangement in FIG. 1b.
• the method according to the invention is carried out within a defined surface segment A, in which the first stamp element 12 is asymmetrically pressed into the metal alloy body 10 in a first process cycle and the second stamp element 13 in a second press cycle is also pressed into the metal alloy body 10, the first stamp element 12 being relaxed in the second pressing cycle without being loaded (left illustration).
• the method according to the invention is then applied to the following surface segment B and to the subsequent surface segments along the surface (illustration on the right).
• FIG. 3 shows a schematic transverse view of the device according to the invention with a first stamp element which is asymmetrical with respect to the central axis.
• the first stamp element 12 is replaced by a force transmitter 14, e.g. a steel plate, pressed into the container 11 (left illustration).
• the bottom of the container 11 is fixed by a steel plate 15 as a corresponding holder.
• the force transmitter 14 is replaced by an asymmetrical force transmitter 14 (middle illustration).
• the force transmitter 14 at the position corresponding to the first stamp element 12, there is a resetting spring element 16 which, during the second process cycle, relaxes the first stamp element 12 while simultaneously compressing the second stamp element 13 in the metal alloy body
• FIG. 4 shows a recording of the grain sizes within a metal alloy body before and after the application of the method according to the invention.
• An AZ31 magnesium alloy with an average grain size of 800 ⁇ m is used as the starting body (FIG. 4A).
• the grain size in the deformation region has been reduced to an average of 17 ⁇ m.
• the reduction in grain size - measured from the outside of the magnesium alloy body - can be measured down to a depth of deformation of 9mm.
• 5 shows two different configurations of the device according to the invention.
• a circular magnesium alloy body 10 is inserted into a circular container 11 with an inner diameter of 30 mm.
• This magnesium alloy body 10 is loaded by a first ring-shaped stamp element 12, the inside diameter of the first stamp element 12 with 15 mm corresponding to the outside diameter of the second stamp element 13.
• the punch elements 12, 13 are connected to an external press (not shown) via a steel plate 14 as a force transmitter.
• the two stamp elements 12, 13 are semicircular, the respective outer diameter of the stamp elements 12, 13 corresponding to the internal pressure gauge of the container 10.
• the force transmitter 14 is provided with a spring-restoring element 16. A spring-like movement of the decompressing first partial area is avoided by the spring-restoring element 16 at the beginning of the second pressing cycle.
• the metal alloy body 10 is characterized in that on two, mutually symmetrical side surfaces with respect to the longitudinal axis of the metal alloy body 10, a reduction in the grain sizes is achieved by the method according to the invention and, above all, the tendency to break and crack due to this sandwich structure with regard to the surfaces processed and unprocessed according to the invention is reduced at the edges of the metal alloy body 10 during further forming, in particular during rolling, of the product according to the invention.

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• Mechanical Engineering (AREA)
• Engineering & Computer Science (AREA)
• Chemical & Material Sciences (AREA)
• Materials Engineering (AREA)
• Thermal Sciences (AREA)
• Crystallography & Structural Chemistry (AREA)
• Physics & Mathematics (AREA)
• Metallurgy (AREA)
• Organic Chemistry (AREA)
• Forging (AREA)
• Manufacture And Refinement Of Metals (AREA)
• Manufacture Of Metal Powder And Suspensions Thereof (AREA)
• Powder Metallurgy (AREA)

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• 2002
  • 2002-09-30 DE DE10245896A patent/DE10245896A1/de not_active Withdrawn
• 2003
  • 2003-09-26 DE DE50308081T patent/DE50308081D1/de not_active Expired - Lifetime
  • 2003-09-26 WO PCT/DE2003/003312 patent/WO2004031431A2/fr active IP Right Grant
  • 2003-09-26 DE DE10393888T patent/DE10393888D2/de not_active Expired - Fee Related
  • 2003-09-26 EP EP03798871A patent/EP1546428B1/fr not_active Expired - Lifetime
  • 2003-09-26 AU AU2003275934A patent/AU2003275934A1/en not_active Abandoned
  • 2003-09-26 AT AT03798871T patent/ATE371753T1/de not_active IP Right Cessation

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