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
  • C22F1/04—Changing the physical structure of non-ferrous metals or alloys by heat treatment or by hot or cold working of aluminium or alloys based thereon
  • C22F1/043—Changing the physical structure of non-ferrous metals or alloys by heat treatment or by hot or cold working of aluminium or alloys based thereon of alloys with silicon as the next major constituent
• • C—CHEMISTRY; METALLURGY
  • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
  • C22C—ALLOYS
  • C22C21/00—Alloys based on aluminium
  • C22C21/02—Alloys based on aluminium with silicon as the next major constituent

Definitions

• the present invention relates to a method for producing a cast component made of an aluminium diecasting alloy of the type disclosed in the preamble of claim 1 .
• the invention further relates to a cast component made of an aluminium diecasting alloy of the type disclosed in the preamble of claim 11 .
• a cast component is produced, by means of which short-term heat stability at 205° C. over a period of 1 hour, for example, or long-term heat stability at 150° C. over a period of 1,000 hours, for example, may be achieved.
• short-term heat stability is necessary for the car body to be appropriately heat-stable, for example, when baking on a layer of paint, this process taking place over 20 mins at 170° C. for example.
• Long-term heat stability is necessary, for example, so the components can withstand corresponding temperatures which are emitted by the motor, for example during vehicle operation, or which act on the components by way of solar radiation.
• crash-sustainable cast components with reduced ductility may be produced, for example, which have a yield point Rp 0.2 of, for example, between 120 and 165 MPa and an elongation at break A 5 of ⁇ 7%.
• Corresponding components with a suitable level of ductility are thus produced and may be used, for example, in the region of a deformable zone.
• alloys In order to be able to produce these components, alloys must be used, for example, which contain a high proportion of the alloy elements Ti, Zr and Mo. However, these alloy elements are extremely expensive and therefore the cast components are ultimately also very expensive.
• the object of the present invention is therefore to provide a method and a cast component of the aforementioned type, by means of which cost-effective production can be achieved.
• an aluminium diecasting alloy by means of which the cast component, as cast, has an elongation at break A 5 of ⁇ 10% and a yield point Rp 0.2 of ⁇ 120 MPa, the cast component being subjected to an annealing process for stability at a temperature of 120 to 260° C. after primary forming.
• an annealing process for stability a correspondingly suitable aluminium diecasting alloy may thus be used in a simple manner so sufficient values are still obtained after the heat treatment.
• the present cast component is in no way limited to use within the region of deformable zones of a motor vehicle.
• the present cast component may also be used at other locations, for example in the region of the chassis or in the region of external attaching parts or components.
• the present invention makes it possible to achieve a sufficient level of heat stability of the cast component in a simple manner in such a way that said component remains heat-stable in the short-term for 1 hour at 205° C. and in the long-term for 1,000 hours at 150° C. without any significant change to the mechanical properties, such as the elongation at break A 5 and the yield point Rp 0.2 .
• a particularly cost-effective aluminium diecasting alloy can thus be produced which comprises ⁇ 8.5% by weight, and in particular ⁇ 8.3% by weight silicon.
• This reduced silicon content in the diecasting alloy may, in particular, be compensated by an optimised content of magnesium.
• the magnesium content is ⁇ 0.6% by weight, and in particular ranges from 0.02 to 0.3% by weight.
• An aluminium diecasting alloy of this type is thus characterised not only by an extremely low silicon content and an optimised magnesium content, but in particular in that the alloy elements Ti, Zr and Mo can be dispensed with in most cases. These alloy elements in particular are influential, namely since they drive up the price of aluminium diecasting alloys.
• an aluminium diecasting alloy is used, by means of which the cast component, as cast, has an elongation at break A 5 of ⁇ 11%, and in particular ⁇ 12%. It should thus be ensured that the cast component also has a sufficient elongation at break A 5 of ⁇ 7% after the heat treatment or annealing process for stability.
• an aluminium diecasting alloy is preferably used, by means of which the cast component, as cast, has an elongation at break A 5 of ⁇ 13%.
• an aluminium diecasting alloy by means of which the cast component, as cast, has a yield point Rp 0.2 of ⁇ 105, and in particular of ⁇ 110 MPa. Starting from this yield point Rp 0.2 it is thus possible to achieve a required yield point Rp 0.2 of ⁇ 120 MPa after heat treatment in a simple manner.
• the magnesium content of the aluminium diecasting alloy within a range of up to 0.6% by weight at most, the cast component, as cast, comprising a yield point Rp 0.2 of ⁇ 80 and in particular of ⁇ 85 MPa.
• the annealing process for stability is carried out at a temperature of 200 to 240° C. It is thus possible to achieve a particularly quick annealing process, the duration of which is, for example, ⁇ 180 mins, and in particular ⁇ 60 mins.
• the annealing process for stability is ultimately carried out in such a way that the heat-treated cast component subsequently has a yield point Rp 0.2 of ⁇ 115 to ⁇ 220 MPa, and in particular ⁇ 125 to ⁇ 165 MPa.
• Particularly advantageous components may thus be obtained which, for example, may be used in the body work of passenger vehicles.
• an aluminium diecasting alloy which comprises the following alloy elements:
• This aluminium diecasting alloy is characterised in that it has a break at elongation A 5 of ⁇ 10% and a yield point Rp 0.2 of ⁇ 120 MPa after the cast component has been cast or primary formed and is immediately in the cast state.
• the components produced from the aforementioned aluminium diecasting alloy are subsequently subjected to an annealing process for stability at between 120 and 260° C., and in particular between 200 to 240° C. for a duration of ⁇ 180 mins, for example approximately 20 mins to 90 mins, and in particular for a duration of 30 mins to 60 mins.
• the cast component After the heat treatment, the cast component has a yield point Rp 0.2 of, for example, approximately 110 to 120 MPa, and in particular between 115 to 118 MPa.
• an aluminium diecasting alloy for the cast components which has the following alloy elements:
• the aluminium diecasting alloy used in this case has an elongation at break A 5 of ⁇ 10% and a yield point Rp 0.2 of ⁇ 120 MPa as cast.
• the respective cast component as cast is subsequently subjected to an annealing process for stability at a temperature of, for example, approximately 120 to 260° C., and in particular at a temperature of 200 to 240° C. within a period of ⁇ 180 mins, for example approximately 20 mins to approximately 90 mins, and in particular within a period of approximately 30 mins to approximately 60 mins.
• the cast component subsequently has an elongation at break A 5 of ⁇ 7% and a yield point of Rp 0.2 , for example, approximately 125 to 135 MPa, and in particular of 129 to 133 MPa.
• an aluminium diecasting alloy for the respective cast component which comprises the following alloy elements:
• the cast components produced using the aforementioned aluminium diecasting alloy have an elongation at break A 5 of ⁇ 10% and a yield point Rp 0.2 of ⁇ 120 MPa as cast, i.e. before any heat treatment.
• the individual cast components are in turn subjected to an annealing process for stability carried out at a temperature ranging from 120 to 260° C., and in particular from 200 to 240° C.
• the annealing process for stability is carried out over a period of up to 180 mins, and in this case, for example, approximately 20 mins to 90 mins, and in particular over a period from 30 to 60 mins.
• the cast components heat-treated in this manner have, after the annealing process for stability, an elongation at break A 5 of ⁇ 7% and a yield point Rp 0.2 ranging between 135 and 150 MPa, and in particular ranging from 141 to 148 MPa.
• an aluminium diecasting alloy which comprises the following alloy elements:
• the cast components produced by the aforementioned aluminium diecasting alloy comprise a elongation at break A 5 of ⁇ 7% and a yield point Rp 0.2 of ⁇ 120 MPa as cast and before the heat treatment.
• the cast components are in turn subjected to an annealing process for stability at a temperature of 120 to 260° C., and in particular between 200 and 240° C.
• the annealing process for stability is thus carried out within a period lasting up to 180 mins, in particular lasting between 20 mins and 90 mins, and in particular within a period lasting between 30 mins and 60 mins.
• cast components are thus produced which, after the heat treatment, have a break at elongation A 5 of ⁇ 7% and a yield point Rp 0.2 ranging from 145 to 165 MPa, and in particular ranging from 151 to 161 MPa.
• heat-treated cast components can be produced by way of a suitable annealing process for stability, which cast components subsequently have an elongation at break A 5 of ⁇ 7% and a yield point Rp 0.2 of ⁇ 110 MPa.
• the yield point can be adjusted to the values given according to Examples 1 to 4, depending on the field in which the respective cast component is to be used.
• magnesium content may be adjusted to a maximum of 0.6% by weight.
• the respective single-step annealing process for stability is, in this case, carried out at a temperature ranging from 120 to 260° C., and in particular ranging from 200 to 240° C.
• the shortest possible annealing process for stability is thus achieved, in which it is ensured that for all cast component samples the required short-term heat stability or long-term stability is obtained without having to excessively or considerably reduce the yield point Rp 0.2 .
• a single-step annealing process for stability of this type with temperatures within the disclosed temperature range, and in particular ⁇ 240° C. may also be carried out during the painting process for example, in particular during the paint baking process of a motor vehicle.
• An annealing process for stability of this type at such temperatures i.e. for example a temperature of ⁇ 240° C. for a duration of ⁇ 180 mins, and in particular ⁇ 60 mins, also has the advantage that the cast components are not distorted and can be heat-treated in a large batch in a batch furnace.
• a particular advantage when using the cast component also lies in that the cast component as cast, i.e. when it has minimum strength (Rp 0.2 approx. 100 MPa) and maximum ductility (A 5 approx. 10 to 14%), can be mechanically joined, for example riveted.
• the subsequent heat treatment which, for example, may be carried out during the painting or paint baking process of the vehicle body at, for example approximately 180° C. for a period of approximately 30 mins, the final mechanical values are set.

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• Chemical & Material Sciences (AREA)
• Engineering & Computer Science (AREA)
• Materials Engineering (AREA)
• Mechanical Engineering (AREA)
• Metallurgy (AREA)
• Organic Chemistry (AREA)
• Physics & Mathematics (AREA)
• Thermal Sciences (AREA)
• Crystallography & Structural Chemistry (AREA)
• Molds, Cores, And Manufacturing Methods Thereof (AREA)
• Body Structure For Vehicles (AREA)
• Forging (AREA)
• Continuous Casting (AREA)

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• 2008
  • 2008-06-24 DE DE102008029864A patent/DE102008029864B4/de active Active
• 2009
  • 2009-06-02 JP JP2009133141A patent/JP2010031360A/ja active Pending
  • 2009-06-11 US US12/483,187 patent/US20090314392A1/en not_active Abandoned
  • 2009-06-23 CA CA002669706A patent/CA2669706A1/en not_active Abandoned
  • 2009-06-24 EP EP09163549A patent/EP2138593A3/de not_active Withdrawn

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