Classifications

• • C—CHEMISTRY; METALLURGY
  • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
  • C22C—ALLOYS
  • C22C1/00—Making non-ferrous alloys
  • C22C1/06—Making non-ferrous alloys with the use of special agents for refining or deoxidising
• • 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 aluminum (Al) casting alloys, particularly for chassis applications.
• sub-eutectic Al alloys having an Si content between 7 and 12 wt.-% are generally used.
• the alloy AlSi11Mg is frequently used; in low-pressure chill-casting the alloy AlSi7Mg is frequently used.
• Low-Si AlSiMg alloys which are characterized by clearly improved mechanical properties as compared with the conventional AlSi casting alloys mentioned above, are known from WO 2007/025528 A2.
• Such an Al casting alloy is stronger, more impact-resistant, and more ductile as compared with the state of the art.
• the preferred alloying-in of Cr in the amounts stated leads to a further significant improvement in the mechanical properties, which can already be recorded in the casting state, but particularly after solution annealing and aging, if applicable.
• the alloys according to the invention can contain contaminants that result from production, for example Pb, Ni, Zn, etc., as they are generally known to a person skilled in the art.
• CuNi is contained as an additional alloy component, by being alloyed in at the same time. It has been shown that additions of copper or nickel alone do not lead to any significant improvement in the mechanical properties. Alloying in copper and nickel at the same time, however, opens up new possibilities for use of the alloy, particularly in the area outside of the chassis, for components subject to temperature stress, preferably for applications close to the engine.
• the alloys according to the invention demonstrate an improved strength/expansion ratio as compared with known Al casting alloys.
• a permanent-mold casting method is suitable as a production method for work pieces, components, or parts for or of chassis parts of motor vehicles, in particular, from the casting alloy according to the invention. Because of the very good mechanical properties in the case of work pieces, components, or parts that are subject to great stress, gravity chill-casting and low-pressure chill-casting are particularly suitable as production methods.
• CPC process low-pressure counter-pressure casting process
• semi-solid casting process as well as other pressure-supported casting methods, such as squeeze-casting, casting/forging such as hybrid processes consisting of forging a cast preform available under the trademark COBAPRESS, or molding system automated low-pressure sand-casting
• CPC process is particularly preferred.
• the alloy has a fine grain.
• grain refiners are added to the alloy.
• Grain refinement is a melt treatment.
• the term “grain refinement” is understood to mean an artificial increase in the number of seed crystals in the melt, which is brought about by the introduction and distribution of outside seed crystals. In this way, better feed capacity by means of improved mass feed, in particular, improved mold-filling and flow capacity, a reduction in the tendency to develop porosity and heat cracks, and a resulting increase in ductility, as well as a better surface composition of the casting alloy are achieved.
• T4 a one-step annealing treatment
• T5 a one-step annealing treatment
• An increase in strength of the castings can advantageously be achieved by means of quenching the castings in water, while they are still hot, instead of allowing them to cool off slowly in air.
• the corrosion resistance is also significantly increased, due to the absence of the alloy components Cu and Zn.
• the product is also relatively inexpensive, because no alloy additives that would make it more expensive, such as Rare Earth (RE) metals, for example, are used, the usual melt treatment can be applied, and no special effort is required for separation of circuits.
• RE Rare Earth
• preferably no Ag is used as an alloy component.
• an excellent strength/expansion ratio is present, with excellent castability.
• the castability allows a casting that is free of large defects, known as blowholes, for one thing, and for another, the microstructure is positively influenced, in such a manner that the number of internal notches, which reduce elongation to fracture, is kept as low as possible.
• the mold-filling capacity is also improved in the presence of Cr, according to the invention.
• the invention furthermore relates to the use of such Al casting alloys for work pieces, components, or parts for or of chassis parts of motor vehicles.
• the alloy according to the invention has proven to be particularly suitable for components subject to greater stress, such as wheel brackets or pivot bearings.
• the low-pressure counter-pressure chill-casting process (CPC process) is used as a preferred method for the production of such components that are subject to greater stress.

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• Chemical & Material Sciences (AREA)
• Engineering & Computer Science (AREA)
• Materials Engineering (AREA)
• Mechanical Engineering (AREA)
• Metallurgy (AREA)
• Organic Chemistry (AREA)
• Continuous Casting (AREA)
• Manufacture Of Alloys Or Alloy Compounds (AREA)
• Body Structure For Vehicles (AREA)

Applications Claiming Priority (5)

Related Parent Applications (1)

Publications (1)

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Country Status (6)

Cited By (11)

Families Citing this family (34)

Citations (9)

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• 2008
  • 2008-11-05 WO PCT/DE2008/001818 patent/WO2009059593A2/fr not_active Ceased
  • 2008-11-05 DE DE112008003601T patent/DE112008003601A5/de not_active Withdrawn
  • 2008-11-05 DE DE102008055928A patent/DE102008055928A1/de not_active Ceased
  • 2008-11-05 CN CN200880115351A patent/CN101855375A/zh active Pending
  • 2008-11-06 IT ITMI2008A001955A patent/IT1392151B1/it active
  • 2008-11-07 FR FR0857580A patent/FR2923493B1/fr not_active Expired - Fee Related
• 2010
  • 2010-05-06 US US12/800,042 patent/US20100288401A1/en not_active Abandoned

Patent Citations (9)

Non-Patent Citations (2)

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