Classifications

• • 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
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B22—CASTING; POWDER METALLURGY
  • B22D—CASTING OF METALS; CASTING OF OTHER SUBSTANCES BY THE SAME PROCESSES OR DEVICES
  • B22D21/00—Casting non-ferrous metals or metallic compounds so far as their metallurgical properties are of importance for the casting procedure; Selection of compositions therefor
  • B22D21/002—Castings of light metals
  • B22D21/007—Castings of light metals with low melting point, e.g. Al 659 degrees C, Mg 650 degrees C
• • 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
  • C22C21/04—Modified aluminium-silicon alloys

Definitions

• the invention relates to a die-casting alloy based on Al-Si, comprising in particular secondary aluminum.
• Inexpensive die-cast alloys can be obtained, for example, from aluminum scrap, but generally disadvantageously contain undesirably high impurities in the form of iron, copper and zinc alloy fractions (EP 1 1 1077A1). This not only leads to a reduced ductility potential, but can also have negative effects on the strength and quench sensitivity of the die-cast alloy.
• Various measures for mutual weighting of the alloying elements, as well as various proposals for alloys are known from the prior art - in particular in order to compensate for the negative influences of the impurities.
• JP9-003610 a die casting alloy with 5 to 13 wt .-% Si, with a maximum of 0.5 wt .-% Mg, with 0.1 to 1, 0 wt .-% Mn and 0.1 to 2 , 0 wt .-% Fe known.
• Mn is intended to suppress the formation of Al-Fe-Si needle crystals, for example, in order to avoid a reduction in strength.
• Mg should be kept to a content as low as possible of at most 0.5% by weight.
• DE102004013777B4 proposes a casting alloy with 5 to 18% by weight of Si, with 0.15 to 0.45% by weight of Mn, with 0.2 to 0.6% by weight of Fe, with 0.3 to 0, 5 wt .-% Mg, with possibly 0.1 to 0.5 wt .-% Cu and 4 to 5 wt .-% Zn before.
• the content of a maximum of 0.5 wt .-% magnesium should avoid the formation of Mg-Fe ' pi ' phases in order to obtain the ductility.
• Cu is said to improve the heat resistance of the alloy, with the content of zinc being limited to 4 to 5% by weight so as to adjust the strength and quenching sensitivity of the alloy.
• DE102009012073A1 a die casting alloy with 9 to 1 1 wt .-% Si, with a maximum of 0.6 wt .-% Fe, with 0.2 to 0.6 wt .-% Mn, with 0.05 to 0 , 4 wt .-% Cu, with 0.2 to 0.35 wt .-% Mg and with a maximum of 0.35 wt .-% Zn known.
• the DE102009012073A1 deals with secondary aluminum - due to the comparatively low lower limits of permissible Cu and Zn contents, the range of usable secondary aluminum is comparatively limited.
• Such a composition can not provide comparatively high strength, ductility and castability, especially since Zn as an impurity should be limited to a small extent.
• the same is also known from DE102005061668A1, according to which the Zn content in the diecasting alloy is to be kept below 0.05% by weight.
• this die-casting alloy is intended for die-casting as well as complex shaping as well as excellent design. moldability and provide excellent workability in the components produced therefrom.
• the invention solves the task by the fact that the die-cast alloy
• Ti titanium
• V vanadium
• the total proportion of Fe and Mn in the die cast alloy together being a maximum of 1.5% by weight, the quotient of the percentages by weight of Fe and Mn 0.35 to 1.5, and the quotient of the percentages by weight of Cu and Mg 0.2 to 0, 8 amount.
• a low-cost diecasting Al-Si-based can be provided because essentially reduces the proportion of primary aluminum or . even refrained from it or that secondary aluminum can be used increased for the production of castings.
• the alloy constituents of the casting alloy are forced according to the invention in particular content limits, so as to the well-known parameters of primary aluminum (eg: strength values, ductility values, chemical reaction stability, processability and / or pourability).
• beta-phase eg: AI 5 FeSi / Al8 9Fe 2 Si2.
• the ⁇ -phase may be present as Al 5 (FeMn) 3 Si 2 due to the manganese content of at least 0.25 wt .-% according to the invention.
• This ⁇ -phase crystallizes in globulitic form and, due to its compact structure, can have a significantly more favorable influence on the ductility than is known from the acicular ⁇ phases.
• a diecasting alloy with a comparatively high ductility can thus be ensured.
• the total content of Fe and Mn in the die-cast alloy is limited to a maximum of 1.5% by weight, the formation of coarse ⁇ -phases can be further reduced, even if the high cooling rates usually used in die-casting processes are used.
• the concentration requirements for Fe and Mn can therefore be particularly beneficial to the ductility of the diecasting alloy.
• this excess of magnesium can improve the curing mechanism of the alloy because part of the Mg is bound in the Q phase (Al 5 Cu 2 Mg 8 Si 6) and thus overcome known limitations due to excessive precipitation of Mg Set 2 Si precursors.
• the concentration requirements for Cu and Mg can therefore satisfy particularly high demands of the diecasting alloy in terms of strength and chemical reaction resistance.
• the proposed concentration ratio of Cu and Mg improved the processability, for example with regard to the weldability and rivability of components made from this diecasting alloy.
• the introduction and / or adjustment of the aforementioned magnesium excess over Cu can also be used to bind the increased Fe content of the die-cast alloy in a pi-phase (Al 8 FeMg 3 Si 6 ).
• the ductility impair beta phase eg. AI 5 FeSi / Al8 9 Fe 2 Si 2
• the Mn content in the diecasting alloy can also be reduced because the pi phase (eg: Al 8 FeMg 3 Si 6 ) can be used to take up Fe.
• Die casting problems usually to be accepted due to an increased Mn content to compensate for Fe effects, can thus be reduced.
• a complex deformation as well as an excellent releasability can be ensured by the special content limits of Mg, Fe, Mn in connection with their concentration requirements.
• the strength of the alloy characterized for example by an interaction of the pre-phases Mg 2 Si and Q-phase (Al 5 Cu 2 Mg 8 Si 6), can be determined by solid-solution hardening be further improved with the help of a zinc deposit.
• zinc is to be adjusted in the content limits of 0.40 to 1, 5 wt .-%.
• this may be beneficial to the ductility of the diecasting alloy.
• the content limits of Zn according to the invention may be distinguished in improving the castability of the die-cast alloy, whereby adverse effects due to the proposed content limits of Mn in the diecasting alloy can be largely compensated.
• the Al-Si-based die-casting alloy balanced in the alloy components Fe, Mn, Cu, Mg and Zn can combine a comparatively high ductility, corrosion resistance, strength, castability and processability, thus overcoming parameter boundaries known from the prior art even if the die-cast alloy has secondary aluminum and / or is added to it or thereby leads to comparatively high levels of impurities.
• the die casting alloy may have 50 to 300 ppm strontium (Sr) and / or 20 to 250 ppm sodium (Na) and / or 20 to 350 ppm antimony (Sb).
• Sr strontium
• Na sodium
• SB antimony
• at most 0.2% by weight of titanium (Ti) and / or at most 0.3% by weight of zirconium and / or at most 0.3% by weight of vanadium (V) may prove to be advantageous.
• the die-cast alloy can be supplemented in each case with 100% by weight of Al, and this diecasting alloy can also lead to unavoidable impurities due to its production.
• the die-cast alloy can have impurities of not more than 0.1% by weight and not more than 1% by weight in total.
• a simple procedure for increasing the proportion of pi-phase (eg: Al 8 FeMg 3 Si6) in the structure of the die-cast alloy can be given. Increased Fe contents can thus be compensated, whereby the best castability of the diecasting alloy can be maintained with a reduced Mn content.
• this pi-phase can be converted with a solution annealing into a harmless for the required properties of the die-cast alloy ⁇ -phase.
• the diecasting alloy can be further improved in terms of achievable ductility, strength and corrosion resistance, if the total content of Fe and Mn on the die-cast alloy together maximally 1, 2 wt .-%, the quotient of the weight percentages of Fe and Mn 0.5 to 1.25 and the quotient of the weight percent of Cu and Mg is 0.2 to 0.5.
• the die cast alloy has 9.5 to 11.5 wt.% Silicon (Si) and / or 0.35 to 0.6 wt.% Iron (Fe) and / or 0.3 to 0.75 wt. % Manganese (Mn) and / or 0.1 to 0.4% by weight copper (Cu) and / or 0.24 to 0.5% by weight magnesium (Mg) and / or 0.40 to 1, 0 Zinc (Zn) results in narrower limits for an improved Al-Si based through-casting alloy in its mechanical and / or chemical resistance.
• the proposed content of Si improves the flow properties of the melt and that brittle primary silicon phases can be avoided. This also makes it possible to pressure-mold even comparatively thin-walled components.
• 9.5 to 1 1, 5 wt .-% silicon (Si) turn out to be particularly advantageous. Way to carry out the invention
• thin-walled cast components were produced by die casting from various die cast alloys.
• the compositions of the alloys studied are listed in Table 1.
• Alloy 1 is a die cast alloy of low contamination primary aluminum.
• Alloy 2 shows a considerable degree of impurities in iron and copper alloy fractions, which can be introduced, for example, by secondary aluminum.
• the alloys and die castings or specimens produced therefrom were subjected to T7 heat treatment for 1 hour at 460 ° C solution annealing, quenching with water and 2 hours aging at 220 ° C.
• the finished test specimens were finally examined for their mechanical properties.
• the tensile strength R m , the yield strength R p0 , 2 and the elongation at break A 5 were determined in the tensile test.
• the measured values obtained are summarized in Table 2.
• concentration ratios for a diecasting alloy proposed according to the invention make it possible to ensure comparatively high ductility, corrosion resistance, strength, castability and processability.

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• 2012
  • 2012-04-26 EP EP12165829.8A patent/EP2657360B1/de active Active
  • 2012-04-26 PL PL12165829T patent/PL2657360T3/pl unknown
  • 2012-04-26 SI SI201230032T patent/SI2657360T1/sl unknown
  • 2012-04-26 ES ES12165829.8T patent/ES2466345T3/es active Active
• 2013
  • 2013-04-10 WO PCT/EP2013/057521 patent/WO2013160108A2/de active Application Filing
  • 2013-04-10 CA CA2871260A patent/CA2871260C/en active Active
  • 2013-04-10 CN CN201380022231.6A patent/CN104350165B/zh active Active
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