US20240189894A1 - Oxidation resistant al-mg high strength die casting foundry alloys - Google Patents

Oxidation resistant al-mg high strength die casting foundry alloys Download PDF

Info

Publication number
US20240189894A1
US20240189894A1 US18/286,532 US202218286532A US2024189894A1 US 20240189894 A1 US20240189894 A1 US 20240189894A1 US 202218286532 A US202218286532 A US 202218286532A US 2024189894 A1 US2024189894 A1 US 2024189894A1
Authority
US
United States
Prior art keywords
alloy
foundry
aluminum
cast
aluminum alloy
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Abandoned
Application number
US18/286,532
Other languages
English (en)
Inventor
Lei Pan
Francis Breton
Martin Morel
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Rio Tinto Alcan International Ltd
Original Assignee
Rio Tinto Alcan International Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Rio Tinto Alcan International Ltd filed Critical Rio Tinto Alcan International Ltd
Priority to US18/286,532 priority Critical patent/US20240189894A1/en
Publication of US20240189894A1 publication Critical patent/US20240189894A1/en
Assigned to RIO TINTO ALCAN INTERNATIONAL LIMITED reassignment RIO TINTO ALCAN INTERNATIONAL LIMITED ASSIGNMENT OF ASSIGNORS INTEREST (SEE DOCUMENT FOR DETAILS). Assignors: BRETON, FRANCIS, MOREL, MARTIN, PAN, LEI
Abandoned legal-status Critical Current

Links

Images

Classifications

    • 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
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22D—CASTING OF METALS; CASTING OF OTHER SUBSTANCES BY THE SAME PROCESSES OR DEVICES
    • B22D17/00—Pressure die casting or injection die casting, i.e. casting in which the metal is forced into a mould under high pressure
    • B22D17/14—Machines with evacuated die cavity
    • 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
    • B22D21/02—Casting exceedingly oxidisable non-ferrous metals, e.g. in inert atmosphere
    • B22D21/04—Casting aluminium or magnesium
    • 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
    • C22C21/06—Alloys based on aluminium with magnesium as the next major constituent

Definitions

  • This disclosure concerns Al—Mg foundry alloys suitable for casting operations, such as high pressure vacuum die-casting operations.
  • Al—Mg die casting foundry alloys have attracted considerable interest due to their superior mechanical properties in as-cast condition.
  • a high amount of Mg (>3%) is added to create Al—Mg alloys.
  • Mg metal-organic compound
  • Al—Mg alloys suffer from problematic oxidation that can result in significant dross formation and loss of Mg from the melt.
  • Beryllium can be used to minimize oxidation as it forms a protective BeO layer at the air-metal interface that inhibits further oxidation of the Mg.
  • Be poses health risks to operators who breathe or come into contact with Be dust.
  • the aluminum die-casting market needs alternatives to Be in Al—Mg alloys to provide a similar oxidation inhibiting effect, but without the health risks. It is also sought to provide an alloy exhibiting improved properties during a casting operation such as die soldering resistance. It is further sought to provide a cast aluminum product exhibiting improved mechanical properties in the as-cast condition (F temper).
  • the present disclosure provides a beryllium-free foundry alloy.
  • the foundry alloy of the present disclosure includes Ca or Sr.
  • the foundry alloy exhibits a reduction in Mg loss and/or in dross generation during the casting operation.
  • the foundry alloy exhibits increased die-soldering resistance during the casting operations.
  • the cast aluminum product made from the foundry aluminum alloy exhibits improved mechanical properties, even in the as-cast state.
  • the present disclosure provides a foundry alloy comprising, in weight percent:
  • the foundry alloy further comprises a grain refiner. In another embodiment, further comprises Ca. In yet another embodiment, the foundry alloy comprises between about 0.01 and about 0.3 Ca in weight percent. In still another embodiment, the foundry alloy comprises between about 3.0 to about 8.0 Mg in weight percent. In yet another embodiment, the foundry alloy comprises between about 4.0 and about 6.0 Mg. In still another embodiment, the foundry alloy comprises between about 0.8 and about 1.8 Fe in weight percent.
  • the present disclosure provides a cast aluminum product comprising the foundry alloy described herein.
  • the cast aluminum is a structural automotive part.
  • the cast aluminum product has at least one of the following properties: an ultimate tensile strength of at least about 200 MPa, a yield strength of at least about 100 MPa; an elongation of at least about 7%; and/or a VDA bend angle of at least about 30°.
  • the cast aluminum product comprises Al 4 Ca.
  • the cast aluminum product has a Al 13 Fe 4 phase, a Al 3 Mg 2 phase and Al 4 Ca.
  • the cast aluminum product has Al 4 Ca jointed with the Al 3 Mg 2 phase.
  • the cast aluminum product of has a AlMgCa phase at the grain boundaries.
  • the present disclosure provides process for making a cast aluminum product, the process comprising casting the foundry aluminum described herein in a mold.
  • the process further comprises submitting the cast aluminum alloy to high-pressure vacuum die casting.
  • the process lacks a post-cast thermal treatment step.
  • the present disclosure provides a cast aluminum product obtainable or obtained by the process described herein.
  • the cast aluminum is a structural automotive part.
  • the cast aluminum product has at least one of the following properties: an ultimate tensile strength of at least about 200 MPa, a yield strength of at least about 100 MPa; an elongation of at least about 7%; and/or a VDA bend angle of at least about 30°.
  • the cast aluminum product comprises Al 4 Ca.
  • the cast aluminum product has a Al 13 Fe 4 phase, a Al 3 Mg 2 phase and Al 4 Ca.
  • the cast aluminum product has Al 4 Ca jointed with the Al 3 Mg 2 phase.
  • the cast aluminum product of has a AlMgCa phase at the grain boundaries.
  • the present disclosure provides a process for limiting Mg loss and dross generation during a casting operation of an aluminum product compared to a control aluminum product.
  • the process comprises adding one of Ca between about 0.003 and about 6.0 or Sr between about 0.003 and about 2.5 to a first aluminum alloy to obtain a foundry alloy intended to be cast.
  • the first aluminum alloy comprises, in weight percent:
  • the process further comprises melting the foundry alloy to obtain a molten foundry alloy.
  • the first aluminum alloy further comprises a grain refiner.
  • the process can be used for reducing Mg loss lower than about 12 weight percent, when the molten foundry alloy is held for a period of at least 6 hours.
  • the process can be used for reducing dross generation lower than about 7 weight percent, when the molten foundry alloy is held for a period of at least 6 hours.
  • the process further comprises casting the molten foundry alloy to obtain a cast aluminum alloy.
  • the process further comprises submitting the cast aluminum alloy to high-pressure vacuum die casting.
  • the process lacks a post-cast heat treatment step.
  • the foundry aluminum alloy comprises Ca. In yet some further embodiments, the foundry aluminum alloy comprises between about 0.01 and about 0.3 Ca. In additional embodiments, the first aluminum alloy comprises between about 3.0 and about 8.0 Mg. In still some embodiments, the first aluminum alloy comprises between about 4.0 and about 6.0 Mg. In yet additional embodiments, the first aluminum alloy comprises between about 0.8 and about 1.8 Fe.
  • FIG. 1 provides the experimental procedure used in the Example.
  • FIG. 2 A provides a picture of the HPVDC plates used in the Example.
  • the dotted line shows the section used for the tensile test presented in the Example.
  • FIG. 2 B provides a representation of ASTM B557 tensile test specimen dimensions used in the Example.
  • FIG. 3 provides pictures of the melt surface evolution during air exposure oxidation tests (from left to right, after skimming, 1 hour, 2 hours or 20 hours holding).
  • FIG. 4 A provides a picture of the solid dross morphology.
  • FIG. 4 B provides an electron micrograph of the dross showing energy dispersive X-ray spectroscopy (EDX)-1 and EDX-2 particles. Scale bar 20 ⁇ m.
  • FIG. 4 C provides EDX-1 results from FIG. 4 B .
  • FIG. 4 D provides EDX-2 results from FIG. 4 B .
  • FIG. 5 A provides the weight percentage of Mg in a base alloy (Ca, Sr and/or a combination of Ca and Sr, stapled line), in an alloy comprising 100 ppm Ca ( ⁇ ), 1000 ppm Ca ( ⁇ ), 100 ppm Sr (X) or 1000 ppm Sr ( ⁇ ) during a holding time of 0 to 6 hours.
  • FIG. 58 provides the percentage in loss of Mg in a base alloy (Ca, Sr and/or a combination of Ca and Sr), in an alloy comprising 100 ppm Ca, 1000 ppm Ca, 100 ppm Sr or 1000 ppm Sr after a total of holding time of 6 hours.
  • FIG. 6 provides pictures of the typical appearance of molten Al-1.5Fe-5Mg base alloy with no additive, with Ca only, Sr only and a combination of Ca and Sr after a 2-hour holding period at 770° C.
  • FIG. 7 provides the total dross generated (in weight percentage) of a base Al-1.5Fe-5Mg alloy, an alloy supplemented with Ca only, Sr only or a combination of Ca and Sr after a total of holding time of 6 hours.
  • FIG. 8 compares the mechanical properties of the base Al-1.5Fe-5Mg alloy and an alloy supplemented with Ca (0.1). Results are shown as ultimate tensile strength (left bars, in MPa), yield strength (middle bars, in MPa), elongation index (left bars, in %) and the quality index ( ⁇ , in MPa) for the two alloys compared.
  • FIG. 9 compares the mechanical properties of comparative alloy 1, comparative alloy 2 (which comprises Be) and the Al-1.5Fe-5Mg0.1Ca alloy. Results are shown as ultimate tensile strength (left bars, in MPa), yield strength (middle bars, in MPa), elongation index (left bars, in %) and the quality index ( ⁇ , in MPa) for the three alloys compared.
  • FIG. 10 A provides a representative optical image of the base Al-1.5Fe-5Mg alloy. Arrows point to porosity in the material. Scale bar 100 ⁇ m.
  • FIG. 10 B provides a representative optical image of the Al-1.5Fe-5Mg0.1Ca alloy. Scale bar 100 ⁇ m.
  • FIG. 10 C provides a representative optical image of the base Al-1.5Fe-5Mg alloy. Scale bar 20 ⁇ m.
  • FIG. 10 D provides a representative optical image of the Al-1.5Fe-5Mg0.1Ca alloy. Scale bar 20 ⁇ m.
  • FIG. 11 A provides scanning electron microscopy (SEM) image, EDX and electron backscatter diffraction (EBSD) of the Al 13 Fe 4 phase found in the Al-1.5Fe-5Mg0.1Ca alloy.
  • FIG. 11 B provides scanning electron microscopy (SEM) image and EDX of the Al 3 Mg 2 phase found in the Al-1.5Fe-5Mg0.1Ca alloy.
  • FIG. 11 C provides scanning electron microscopy (SEM) image, EDX and electron backscatter diffraction (EBSD) of the Al 4 Ca constituent found in the Al-1.5Fe-5Mg0.1Ca alloy.
  • FIG. 11 D provides scanning electron microscopy (SEM) image and EDX mapping of the Al—Mg—Ca phase found in the Al-1.5Fe-5Mg0.1Ca alloy.
  • FIG. 12 provides results showing the effect of Mg on the yield strength of the alloy.
  • Aluminum alloys provide attractive solutions in the automotive industry to achieve lightweight objectives for improving fuel efficiency and reducing CO 2 emissions.
  • HPVDC high pressure vacuum die casting
  • Alloys for structural die castings typically require good fluidity and die soldering resistance, high mechanical properties and sufficient corrosion resistance.
  • Key challenges that are being addressed in the industry are die soldering, blistering during solution treatment, and requirement on the combination of strength and ductility.
  • Well-designed aluminum alloys for F and T5 tempers are preferable from a broader cost and quality perspective.
  • Al—Mg foundry alloys Be is often used to limit or inhibit oxidation.
  • the foundry aluminum alloy of the present disclosure comprises either Ca or Sr.
  • the foundry aluminum alloy does not include a combination of Ca and Sr.
  • Ca and Sr limit the oxidation of the alloy as well as, in some embodiments, improve the casting conditions.
  • the foundry aluminum alloy can also improve one or more mechanical properties of the cast product (in some embodiments in its as-cast state).
  • the foundry aluminum alloy of the present disclosure can be any Al—Mg foundry alloy that is suitable for casting operations.
  • the foundry aluminum alloy of the present disclosure can be a 5xx.x aluminum alloy.
  • Ca is present in the foundry aluminum alloy at a weight percentage equal to or higher than about 0.003. In some embodiments, Ca is present in the foundry aluminum alloy at a weight percentage equal to or higher than about 0.01. In some embodiments, Ca is present in the foundry aluminum alloy at a weight percentage equal to or higher than about 0.1.
  • Ca is present at a weight percentage of at least about 0.003, 0.004, 0.005, 0.006, 0.007, 0.008, 0.009, 0.01, 0.02, 0.03, 0.04, 0.05, 0.06, 0.07, 0.08, 0.09, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1.0, 2.0, 3.0, 4.0, 5.0 or higher.
  • Ca is present in the alloy, it is present at a weight percentage equal to or below 6.0.
  • Ca is present in the alloy at a weight percentage of no more than about 6.0, 5.0, 4.0, 3.0, 2.0, 1.0, 0.9, 0.8, 0.7, 0.6, 0.5, 0.4, 0.3, 0.2, 0.1, 0.09, 0.08, 0.07, 0.06, 0.05, 0.04, 0.03, 0.02 or lower.
  • Ca is present in the alloy at a weight percentage between about 0.01 to about 6.0.
  • Ca is present at a weight percentage of at least about 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1.0 or higher.
  • Ca is present in the alloy at a weight percentage of no more than about 6.0, 5.0, 4.0, 3.0, 2.0, 1.0, 0.9, 0.8, 0.7, 0.6, 0.5, 0.4, 0.3, 0.2 or lower. In some specific embodiments, Ca is present in the alloy at a weight percentage between about 0.1 to about 6.0. In yet other embodiments, Ca is present in the alloy at a weight percentage of at least about 0.01, 0.02, 0.03, 0.04, 0.05, 0.06, 0.07, 0.08, 0.09, 0.1, 0.2 or higher.
  • Ca is present in the alloy at a weight percentage of no more than about 0.3, 0.2, 0.1, 0.09, 0.08, 0.07, 0.06, 0.05, 0.04, 0.03, 0.02 or lower. In yet additional embodiments, Ca is present in the alloy at a weight percentage between about 0.01, 0.02, 0.03, 0.04, 0.05, 0.06, 0.07, 0.08, 0.09, 0.1 or 0.2 and about 0.3, 0.2, 0.1, 0.09, 0.08, 0.07, 0.06, 0.05, 0.04, 0.03 or 0.02, such as, for example, at a weight percentage between about 0.01 and about 0.3. In yet other embodiments, Ca is present in the alloy at a weight percentage of at least about 0.1, 0.2 or higher.
  • Ca is present in the alloy at a weight percentage of no more than about 0.3, 0.2 or lower. In yet additional embodiments, Ca is present in the alloy at a weight percentage between about 0.1 or 0.2 and about 0.3 or 0.2, such as, for example, at a weight percentage between about 0.1 and about 0.3.
  • Sr is present in the alloy at a weight percentage equal to or higher than about 0.003. In some embodiments, Sr is present in the alloy at a weight percentage equal to or higher than about 0.01. In some embodiments, Sr is present in the alloy at a weight percentage equal to or higher than about 0.1.
  • Sr is present at a weight percentage of at least about 0.003, 0.004, 0.005, 0.006, 0.007, 0.008, 0.009, 0.01, 0.02, 0.03, 0.04, 0.05, 0.06, 0.07, 0.08, 0.09, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1.0, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, 2.0, 2.1, 2.2, 2.3, 2.4 or higher.
  • Sr is present in the alloy, it is present at a weight percentage equal to or below 2.5.
  • Sr is present in the alloy at a weight percentage of no more than 2.5, 2.4, 2.3, 2.2, 2.1, 2.0, 1.9, 1.8, 1.7, 1.6, 1.5, 1.4, 1.3, 1.2, 1.1, 1.0, 0.9, 0.8, 0.7, 0.6, 0.5, 0.4, 0.3, 0.2, 0.1, 0.09, 0.08, 0.07, 0.06, 0.05, 0.04, 0.03, 0.02, 0.01, 0.009, 0.008, 0.007, 0.006, 0.005, 0.004 or lower. In some specific embodiments, Sr is present in the alloy at a weight percentage between about 0.003 to about 2.5.
  • Sr is present at a weight percentage of at least about 0.01, 0.02, 0.03, 0.04, 0.05, 0.06, 0.07, 0.08, 0.09, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1.0, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, 2.0, 2.1, 2.2, 2.3, 2.4 or higher.
  • Sr is present in the alloy at a weight percentage of no more than about 2.5, 2.4, 2.3, 2.2, 2.1, 2.0, 1.9, 1.8, 1.7, 1.6, 1.5, 1.4, 1.3, 1.2, 1.1, 1.0, 0.9, 0.8, 0.7, 0.6, 0.5, 0.4, 0.3, 0.2, 0.1, 0.09, 0.08, 0.07, 0.06, 0.05, 0.04, 0.03, 0.02 or lower. In some specific embodiments, Sr is present in the alloy at a weight percentage between about 0.01 to about 2.5.
  • Sr is present at a weight percentage of at least about 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1.0, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, 2.0, 2.1, 2.2, 2.3, 2.4 or higher.
  • Sr is present in the alloy at a weight percentage of no more than about 2.5, 2.4, 2.3, 2.2, 2.1, 2.0, 1.9, 1.8, 1.7, 1.6, 1.5, 1.4, 1.3, 1.2, 1.1, 1.0, 0.9, 0.8, 0.7, 0.6, 0.5, 0.4, 0.3, 0.2 or lower.
  • Sr is present in the alloy at a weight percentage between about 0.1 to about 2.5. In yet other embodiments, Sr is present in the alloy at a weight percentage of at least about 0.01, 0.02, 0.03, 0.04, 0.05, 0.06, 0.07, 0.08, 0.09, 0.1 or 0.2. In yet further embodiments, Sr is present in the alloy at a weight percentage of no more than about 0.3, 0.2, 0.1, 0.09, 0.08, 0.07, 0.06, 0.05, 0.04, 0.03, 0.02 or lower.
  • Sr is present in the alloy at a weight percentage between about 0.01, 0.02, 0.03, 0.04, 0.05, 0.06, 0.07, 0.08, 0.09, 0.1 or 0.2 and about 0.3, 0.2, 0.1, 0.09, 0.08, 0.07, 0.06, 0.05, 0.04, 0.03 or 0.02, such as, for example, at a weight percentage between about 0.01 and about 0.3.
  • Sr is present in the alloy at a weight percentage of at least about 0.1, 0.2 or higher.
  • Sr is present in the alloy at a weight percentage of no more than about 0.3, 0.2 or lower.
  • Sr is present in the alloy at a weight percentage between 0.1 or 0.2 and about 0.3 or 0.2, such as, for example, at a weight percentage between about 0.1 and about 0.3.
  • the foundry aluminum alloy of the present disclosure comprises Mg to provide acceptable mechanical properties in the resulting cast product. Since the main strengthening mechanism of Mg is solid solution strengthening, adding more than the Mg's solubility in aluminum would not further increase the mechanical properties of the corresponding aluminum cast product. As such, in the foundry aluminum alloy of the present disclosure, Mg is provided at a weight percentage of 17.0 or less. Mg is present in the alloy at a weight percentage of at least about 1.0, 2.0, 3.0, 4.0, 5.0, 6.0, 7.0, 8.0, 9.0, 10.0, 11.0, 12.0, 13.0, 14.0, 15.0, 16.0 or more.
  • Mg is present in the alloy at a weigh percentage of no more than about 17.0, 16.0, 15.0, 14.0, 13.0, 12.0, 11.0, 10.0, 9.0, 8.0, 7.0, 6.0, 5.0, 4.0, 3.0, 2.0 or less.
  • Mg is present in the alloy at a weight percentage of between about 1.0, 2.0, 3.0, 4.0, 5.0, 6.0, 7.0, 8.0, 9.0, 10.0, 11.0, 12.0, 13.0, 14.0, 15.0, 16.0 and about 17.0, 16.0, 15.0, 14.0, 13.0, 12.0, 11.0, 10.0, 9.0, 8.0, 7.0, 6.0, 5.0, 4.0, 3.0, 2.0, such as, for example, between about 1.0 and 17.0.
  • Mg is present in the alloy at a weight percentage of at least about 3.0, 4.0, 5.0, 6.0, 7.0 or more.
  • Mg is present in the alloy at a weight percentage of no more than about 8.0, 7.0, 6.0, 5.0, 4.0 or less. In an embodiment, Mg is present in the alloy at a weight percentage of between about 3.0, 4.0, 5.0, 6.0, 7.0 and about 8.0, 7.0, 6.0, 5.0, 4.0, such as, for example, between about 3.0 and 8.0. In some embodiments, Mg is present in the alloy at a weight percentage of at least about 4.0, 5.0 or more. In some embodiments, Mg is present in the alloy at a weight percentage of no more than about 6.0, 5.0 or less. In an embodiment, Mg is present in the alloy at a weight percentage of between about 4.0, 5.0 and about 6.0, 5.0, such as, for example, between about 4.0 and 6.0.
  • the foundry aluminum alloy of the present disclosure comprises Fe to provide die soldering resistance during casting operations.
  • the amount of Fe present in the foundry alloy of the present disclosure should be limited so as to avoid creating large iron phases that are brittle and could reduce the mechanical properties of the corresponding aluminum alloy product.
  • Fe is present in the alloy at a weight percentage of at least about 0.5, 0.6, 0.7, 0.8, 0.9, 1.0, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7 or more.
  • Fe is present in the alloy at a weight percentage of no more than about 1.8, 1.7, 1.6, 1.5, 1.4, 1.3, 1.2, 1.1, 1.0, 0.9, 0.8, 0.7, 0.6 or less.
  • Fe is present in the alloy at a weight percentage of between about 0.5, 0.6, 0.7, 0.8, 0.9, 1.0, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7 and about 1.8, 1.7, 1.6, 1.5, 1.4, 1.3, 1.2, 1.1, 1.0, 0.9, 0.8, 0.7, 0.6, such as, for example, between about 0.5 and 1.8.
  • Fe is present in the alloy at a weight percentage of at least about 0.8, 0.9, 1.0, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7 or more.
  • Fe is present in the alloy at a weight percentage of no more than about 1.8, 1.7, 1.6, 1.5, 1.4, 1.3, 1.2, 1.1, 1.0, 0.9, or less. In an embodiment, Fe is present in the alloy at a weight percentage of between about 0.8, 0.9, 1.0, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7 and about 1.8, 1.7, 1.6, 1.5, 1.4, 1.3, 1.2, 1.1, 1.0, 0.9, such as, for example, between about 0.8 and 1.8.
  • a grain refiner may be optionally included in the aluminum alloys of the present disclosure to solidify aluminum alloys with a fully equiaxed, fine grain structure, in the form of Ti, TiB2, TiB or TiC.
  • TiB is used as a grain refiner, this may result in a B content of up to 0.05 wt. % in the alloy.
  • TiC is used as a grain refiner, this may result in a C content of up to 0.01 wt. % in the alloy.
  • the grain refiner can be added during manufacture of the ingot to be remelted or it can be added after remelting during production of the final casting.
  • the foundry alloys of the present disclosure lack Be as a deliberation addition or as an alloying element. When present, Be is considered to be an unavoidable impurity.
  • the foundry alloy lacks Cu as a deliberation addition or as an alloying element.
  • Cu when present, Cu can be considered to be an unavoidable impurity.
  • each impurity is present, in weight percent, at a maximum of about 0.05 and the total unavoidable impurities is present, in weight percent, at less than about 0.15 (in weight percent).
  • the cast aluminum alloy of the present disclosure can be submitted to various casting operations including, but not limited to high-pressure vacuum die casting (HPVDC) so as to provide cast aluminum product.
  • HPVDC high-pressure vacuum die casting
  • the presence of Ca or Sr can, in some embodiments, improve the casting operations by reducing the amount of Mg loss and/or of dross generation during the holding of the melted aluminum alloy.
  • the presence of Ca or Sr can reduce Mg loss during melting lower than about 12 weight percent (when compared to a corresponding base alloy—Ca, Sr and/or a combination of Ca and Sr) when the molten alloy is held for at least 6 hours.
  • the presence of Ca or Sr can reduce dross generation lower than about 7 weight percent (when compared to a corresponding base alloy lacking Ca and Sr) when the molten alloy is held for at least 6 hours.
  • the present disclosure therefore provides a process for making a cast aluminum product from the foundry aluminum alloy described herein.
  • the process encompasses casting the foundry aluminum alloy described herein in a mold and optionally submitting the cast aluminum alloy to high-pressure vacuum die casting (HPVDC).
  • HPVDC high-pressure vacuum die casting
  • the process avoids using a post-cast thermal treatment step.
  • the corresponding aluminum product is provided in the as-cast state (e.g., F temper).
  • the foundry aluminum alloy which can be provided in the form of an ingot, is submitted to a melting step to obtain a melted aluminum alloy.
  • the melting step includes heating and stirring the aluminum alloy and optionally holding the melted aluminum alloy prior to casting. If a dross is generated during the melting step (for example during the holding step), the process can include removing the dross prior to casting. Once a melted aluminum alloy is obtained, it is cast in a mold to obtain a cast aluminum product.
  • the casting step can include submitting the cast aluminum alloy to a high-pressure vacuum die-casting step.
  • the process can include a step of removing the cast aluminum product from the mold.
  • the process for making the cast aluminum product lacks a post-cast thermal treatment step and the cast aluminum product is provided in the as-cast state (e.g., F temper).
  • the process for making the cast aluminum can include one or more post-cast treatment step (e.g., an annealing step, a strain hardening step, a solution heat treatment step and/or a thermal treatment step).
  • the process can also exclude any post-cast treatment (e.g., it can be provided as cast or F temper).
  • the process can include a post-cast heat treatment, such as, for example, a T5, T6 or T7 treatment (e.g., solution heat treatment and artificial aging steps).
  • a post-cast heat treatment such as, for example, a T5, T6 or T7 treatment (e.g., solution heat treatment and artificial aging steps).
  • the aluminum product is a cast product
  • the latter can be an automotive part, such as a chassis or a rotor.
  • the foundry alloys of the present disclosure can be used to reduce dross generation during the casting operation. In some embodiments, the foundry alloys of the present disclosure reduces the weight percent of the dross generated during the melting step (for example during the holding step) below 7, 6, 5, 4, 3, 2, 1% when the melted aluminum alloy is held for a period of at least 6 hours.
  • the foundry alloys of the present disclosure can be used to reduce the loss of Mg during the casting operation. In some embodiments, the foundry alloys of the present disclosure reduces the weight percent of Mg lost during the melting step (for example during the holding step) below 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2% or lower when the melted aluminum alloy is held for a period of at least 6 hours.
  • the process of the present disclosure can include adding Ca or Sr to aluminum or to a first aluminum alloy to provide a master alloy or the foundry alloy of the present disclosure.
  • Ca or Sr is added to pure aluminum to provide a master alloy.
  • the master alloy can then be used to make the foundry alloy of the present disclosure and be supplemented with Mg, Fe and optionally a grain refiner.
  • the pure aluminum or the master alloy lacks Be as an alloying element and, if Be is present, it is considered an impurity.
  • Ca or Sr is added to a first aluminum alloy comprises Mg and Fe, and optionally a grain refiner, the balance being aluminum and unavoidable impurities.
  • the first aluminum alloy lacks Be as an alloying element and, if Be is present in the first aluminum alloy, it is considered an impurity.
  • the present disclosure also provides cast aluminum products are obtainable or can be obtained by the process described herein.
  • the term “cast aluminum product” can refer to a final cast products (such as a structural automotive part for example) or to an intermediary ingot which can further be remelted into a differently shaped aluminum product.
  • the cast aluminum product is a shock tower, a A-pillar, a B-pillar or a torque box.
  • the cast aluminum product of the present disclosure exhibits an improved ultimate tensile strength, yield strength, quality index, VDA angle and/or percent elongation when compared to the characteristics of a corresponding aluminum product lacking Ca or Sr (and optionally comprising Be).
  • the improved ultimate tensile strength, yield strength, quality index, VDA angle and/or percent elongation are observed in the as-cast state of the aluminum product (e.g., F temper).
  • the cast aluminum products made from the foundry alloy of the present disclosure have an ultimate tensile strength of at least about 200, 210, 220, 230, 240, 250 MPa or more. In a specific embodiment, the cast aluminum products made from the foundry alloy of the present disclosure have an ultimate tensile strength of at least about 200 MPa. In some additional embodiments, the cast aluminum products made from the foundry alloy of the present disclosure have a yield strength of at least about 100, 110, 120, 130, 140, 150 MPa or more. In some additional embodiments, the cast aluminum products made from the foundry alloy of the present disclosure have a yield strength of at least about 100 MPa.
  • the cast aluminum products made from the foundry alloy of the present disclosure have an elongation of at least about 7, 8, 9, 10% or more. In some additional embodiments, the cast aluminum products made from the foundry alloy of the present disclosure have an elongation of at least about 7%. In some additional embodiments, the cast aluminum products made from the foundry alloy of the present disclosure meets the standard VDA (Verband der Automobilindustrie) 238-100 angle of at least about 30° or more.
  • VDA Veryband der Automobilindustrie
  • This present example presents the development of a new aluminum alloy to provide excellent mechanical properties and die soldering resistance for aluminum HPVDC structural components in as cast temper application.
  • the microstructural evolution and mechanical properties were studied by scanning electron microscopy and tensile/bend tests. The relationship between the microstructure and properties are analyzed and the strengthening mechanisms of the studied alloy are discussed. Based on the experimental results, the new alloy demonstrates a promising solution for HPVDC components to be applied in as-cast condition.
  • the experimental procedure is presented in FIG. 1 .
  • the procedure includes two steps: alloy batching and holding process.
  • a typical alloy batching process was used. More specifically, P1020 was charged into the furnace and batched with Fe and Mg. Then, the molten metal was stirred and degassed using Argon. Fluxing salt was used to clean the melt during degassing. After degassing, Ca and Sr were added in a proportion of 100 ppm to 0.3% for Ca and 100 to 1000 ppm for Sr, as per the chemistry design in Table 1.
  • An interrupted thermal holding process was used to investigate oxidation generation during casting. The holding temperature of the metal was set to 770° C., which is the high limit for typical casting.
  • the test demonstrates the effect of Ca and Sr on Al—Mg oxidation under the most aggressive oxidation conditions.
  • FIG. 1 three holding periods of two hours each followed the alloying. After each period, the molten metal surface appearance was captured. Complete skimming of the metal surface was carried out to quantify dross generation. Six OES samples were taken to evaluate the loss of magnesium. After each test, the crucible was thoroughly cleaned. For the base Al-1.5Fe-5Mg alloy, a prolonged thermal holding time of up to 20 hours was performed to study the oxidation evolution.
  • Samples for tensile tests were cut from casting blanks (rectangular part in the middle of the sample, as shown in FIG. 2 ). The plates were then machined into the form of test samples with precise dimensions which meet the ASTM B557 standards. For each alloy, ten tensile samples in as-cast condition were pulled. Square samples of 60 ⁇ 60 mm were machined from 3 mm HPVDC plates for bend tests. Six samples of each alloy were tested according to VDA 238-100 norm.
  • Metallographic samples were taken from as-cast HPVDC plates. Optical microscopy and scanning electron microscopy (SEM) were used to analyze the as-cast microstructure and to identify the intermetallic phases.
  • FIG. 3 shows the melt surface of Al-1.5Fe-5Mg alloy during thermal holding at 770° C. in air.
  • the surface of the melt is very clean after thorough skimming. After a 1-hour exposure, the surface presents a partial popcorn-shaped oxidation near the crucible edge. After a 2-hour exposure, the surface of the melt becomes completely covered with popcorn-shaped oxides.
  • the metal temperature increased to 800° C. due to the exothermic oxidation reaction of aluminium and magnesium. After a 20-hour exposure, the colour of the oxides turns partially black.
  • Solid popcorn-shaped oxides have a porous morphology, as shown in FIG. 4 A , which constitutes a large number of pores and oxide clusters (see FIG. 4 B ).
  • EDX analysis shows that the dross is mainly composed of magnesium oxide (MgO) and spinel (MgAl 2 O 4 ).
  • FIGS. 5 A and 5 B show that the Mg concentration changes during a holding time of 0 to 6 hours, as well as the percentage in loss of Mg after a total of holding time of 6 hours. It can be observed that the base Al-1.5Fe-5Mg alloy had the highest Mg loss. The total Mg loss after 6 hours holding period is 0.63 wt. %, or 12.6% loss. Additions of Ca or Sr effectively reduced the Mg loss during melting. The Mg loss was lower than 0.1 wt. %, or 2% loss for alloys containing Ca, and lower than 0.3 wt. %, or 6% loss for alloys containing Sr.
  • FIG. 6 shows the visual appearance of molten Al-1.5Fe-5Mg base alloy with no additive, with Ca only, Sr only, and the combination of Ca and Sr.
  • the alloy containing both Ca and Sr has a small wavy shape. This characteristic is similar to that of the alloy containing Sr.
  • the oxidation layer appears to be thick There is no porous dross. This result indicates that the combination of Ca and Sr can effectively help withstand Al-1.5Fe-5Mg oxidation.
  • FIG. 7 shows the total dross generated (wt. % of the charge) after a total of holding time of 6 hours. It is noted that the combination of Ca and Sr effectively reduced dross generation.
  • the alloy with both Ca and Sr showed a dross generation of 2.1 wt. %, which is lower than that of the base alloy (6.9 wt. %) and that of the alloy with Sr (2.9 wt. %). However, the amount of dross generated is higher than that of the alloy with Ca (1.0 wt. %).
  • the Mg in Al-1.5Fe-5Mg has a strong affinity for oxygen. Heavy oxides were found at the melt surface for the base alloy. Both Ca and Sr demonstrated a positive effect in inhibiting Al-1.5Fe-5Mg oxidation.
  • FIG. 9 shows the comparison of the mechanical properties of the new Al-1.5Fe-5Mg0.1Ca alloy with those of other commercial die casting alloys (e.g., comparative alloys 1 and 2).
  • the new alloy showed a higher quality index value than comparative alloys 1 and 2. It had the highest overall tensile strength and yield strength.
  • the Al-1.5Fe-5Mg0.1Ca alloy had higher tensile strength and lower elongation.
  • the elongation was 10% in the Al-1.5Fe-5Mg0.1Ca alloy vs. 11.5% in comparative alloy 1.
  • the Al-1.5Fe-5Mg0.1Ca alloy showed better bending ductility than comparative alloy 1, with a bending angle of 37.7° in the Al-1.5Fe-5Mg0.1Ca alloy compared to 32.4° in the comparative alloy 1.
  • the Al-1.5Fe-5Mg0.1Ca alloy is expected to have similar or better ductility than the comparative alloy 1.
  • the Al-1.5Fe-5Mg0.1Ca alloy contains 1.5 wt. % Fe, which is expected to reduce the tendency to stick and significantly improve die life compared to the comparative alloy 1.
  • the Al-1.5Fe-5Mg0.1Ca alloy showed higher strength but lower ductility. Without wishing to be bound to theory, this may be due to the higher Mg content in the Al-1.5Fe-5Mg0.1Ca alloy (5.1 wt. % Mg) than in the comparative alloy 2 (4.3 wt. % Mg), which provided a higher solid solution strengthening effect.
  • the ductility of the Al-1.5Fe-5Mg0.1Ca alloy can be improved by decreasing the Mg amount if a higher elongation is needed.
  • the Al-1.5Fe-5Mg0.1Ca alloy showed a higher quality index value (459 MPa) than the comparative alloy 2 (427 MPa).
  • the Al-1.5Fe-5Mg0.1Ca alloy had overall better mechanical properties than the comparative alloy 2.
  • the Al-1.5Fe-5Mg0.1Ca alloy is expected to perform similarly to the comparative alloy in terms of die life.
  • Al-1.5Fe-5Mg shows shrinkage porosities while Al-1.5Fe-5Mg0.1Ca shows a porosity-free microstructure. Since Ca is very efficient in reducing Al—Mg oxidation, it is logical that Al-1.5Fe-5Mg0.1Ca has lower oxides and lower porosity.
  • Phase morphology and chemistry identification were carried out using SEM/EDX and EBSD analyses. The results are shown in FIG. 11 .
  • Table 4 summarizes the different stable phases identified in the two alloys of the study.
  • the alloy matrix mainly consisted of Al 13 Fe4 and Al 3 Mg 2 phases in Al-1.5Fe-5Mg alloy, and Al 13 Fe 4 and A6Mg 2 /Al 4 Ca phases in Al-1.5Fe-5Mg0.1Ca alloy. Addition of Ca in the Al-5Mg-1.5Fe alloy allows the formation of the Al 4 Ca phase jointed with the Al 3 Mg 2 phase or AlMgCa phase at the grain boundaries in the matrix. In addition, Ca appears to slightly modify the morphology of the iron-rich phases.

Landscapes

  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Chemical & Material Sciences (AREA)
  • Materials Engineering (AREA)
  • Metallurgy (AREA)
  • Organic Chemistry (AREA)
  • Mold Materials And Core Materials (AREA)
  • Continuous Casting (AREA)
US18/286,532 2021-04-14 2022-04-01 Oxidation resistant al-mg high strength die casting foundry alloys Abandoned US20240189894A1 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
US18/286,532 US20240189894A1 (en) 2021-04-14 2022-04-01 Oxidation resistant al-mg high strength die casting foundry alloys

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
US202163174796P 2021-04-14 2021-04-14
PCT/CA2022/050497 WO2022217338A1 (en) 2021-04-14 2022-04-01 Oxidation resistant al-mg high strength die casting foundry alloys
US18/286,532 US20240189894A1 (en) 2021-04-14 2022-04-01 Oxidation resistant al-mg high strength die casting foundry alloys

Publications (1)

Publication Number Publication Date
US20240189894A1 true US20240189894A1 (en) 2024-06-13

Family

ID=83639360

Family Applications (1)

Application Number Title Priority Date Filing Date
US18/286,532 Abandoned US20240189894A1 (en) 2021-04-14 2022-04-01 Oxidation resistant al-mg high strength die casting foundry alloys

Country Status (7)

Country Link
US (1) US20240189894A1 (https=)
EP (1) EP4323557A4 (https=)
JP (1) JP2024514616A (https=)
KR (1) KR20230171947A (https=)
CA (1) CA3215898A1 (https=)
MX (1) MX2023012203A (https=)
WO (1) WO2022217338A1 (https=)

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US8016958B2 (en) * 2006-07-18 2011-09-13 Nippon Light Metal Company, Ltd. High strength aluminum alloy sheet and method of production of same
US20180298473A1 (en) * 2017-04-15 2018-10-18 The Boeing Company Aluminum alloy with additions of magnesium, calcium and at least one of chromium, manganese and zirconium, and method of manufacturing the same

Family Cites Families (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2090289B (en) * 1980-12-23 1985-05-22 Aluminum Co Of America Wrought aluminum base alloy having refined intermetallic phases
US4412870A (en) * 1980-12-23 1983-11-01 Aluminum Company Of America Wrought aluminum base alloy products having refined intermetallic phases and method
US4406717A (en) * 1980-12-23 1983-09-27 Aluminum Company Of America Wrought aluminum base alloy product having refined Al-Fe type intermetallic phases
DE60231046D1 (de) * 2001-07-25 2009-03-19 Showa Denko Kk Aluminiumlegierung mit hervorragender zerspanbarkeit und aluminiumlegierungsmaterial und herstellungsverfahren dafür

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US8016958B2 (en) * 2006-07-18 2011-09-13 Nippon Light Metal Company, Ltd. High strength aluminum alloy sheet and method of production of same
US20180298473A1 (en) * 2017-04-15 2018-10-18 The Boeing Company Aluminum alloy with additions of magnesium, calcium and at least one of chromium, manganese and zirconium, and method of manufacturing the same

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
Davis, J.R. "Aluminum and Aluminum Alloys", ASM International, p 89-91, 97. (Year: 1993) *

Also Published As

Publication number Publication date
EP4323557A1 (en) 2024-02-21
MX2023012203A (es) 2023-10-25
JP2024514616A (ja) 2024-04-02
EP4323557A4 (en) 2025-04-16
KR20230171947A (ko) 2023-12-21
CA3215898A1 (en) 2022-10-20
WO2022217338A1 (en) 2022-10-20

Similar Documents

Publication Publication Date Title
EP2677049B1 (en) Aluminium alloy comprising magnesium and calcium
KR101124235B1 (ko) 알루미늄 합금 및 알루미늄 합금 주물
CA2721761C (en) Aluminum alloy and manufacturing method thereof
JP7152977B2 (ja) アルミニウム合金
JP5703881B2 (ja) 高強度マグネシウム合金およびその製造方法
CN117026023B (zh) 一种免热处理高强高韧压铸铝合金及其制备方法
CN115852211A (zh) 免热处理铝合金及其制备方法
EP3216884B1 (en) Aluminum alloy for die casting and aluminum-alloy die cast obtained therefrom
JP2022177040A (ja) ダイカスト用アルミニウム合金及びアルミニウム合金ダイカスト材
KR20120073194A (ko) 알루미늄 합금
CN113046606A (zh) 铝合金及其制备方法和铝合金结构件
JP2018168468A (ja) アルミニウム合金クラッド材及びその製造方法
JP7191077B2 (ja) 高強度耐食性アルミニウム合金およびその製造方法
JP6900199B2 (ja) 鋳造用アルミニウム合金、アルミニウム合金鋳物製品およびアルミニウム合金鋳物製品の製造方法
US20240189894A1 (en) Oxidation resistant al-mg high strength die casting foundry alloys
CN117604341A (zh) 高冲击韧性铝镁硅合金材料及构件的铸造方法
JP7705744B2 (ja) アルミニウム合金、アルミニウム合金熱間加工材及びその製造方法
JP7409195B2 (ja) 鋳造用アルミニウム合金、アルミニウム合金鋳物及びその製造方法
JP5522692B2 (ja) 高強度銅合金鍛造材
JP7814676B2 (ja) 鋳物用アルミニウム合金及びアルミニウム合金鋳物
JP6649665B2 (ja) マグネシウム合金製造方法、マグネシウム合金圧延材、およびマグネシウム合金成形体
WO2024242135A1 (ja) アルミニウム合金鋳塊の製造方法、アルミニウム合金連続鋳造棒、及び、アルミニウム合金鍛造品
JP2024064611A (ja) アルミニウム合金の製造方法
EP3342888B1 (en) Aluminium casting alloy
RU2623932C1 (ru) Деформируемый термически неупрочняемый сплав на основе алюминия

Legal Events

Date Code Title Description
STPP Information on status: patent application and granting procedure in general

Free format text: RESPONSE TO NON-FINAL OFFICE ACTION ENTERED AND FORWARDED TO EXAMINER

STPP Information on status: patent application and granting procedure in general

Free format text: NON FINAL ACTION MAILED

STPP Information on status: patent application and granting procedure in general

Free format text: RESPONSE TO NON-FINAL OFFICE ACTION ENTERED AND FORWARDED TO EXAMINER

AS Assignment

Owner name: RIO TINTO ALCAN INTERNATIONAL LIMITED, CANADA

Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:PAN, LEI;BRETON, FRANCIS;MOREL, MARTIN;SIGNING DATES FROM 20210426 TO 20210428;REEL/FRAME:069246/0240

STPP Information on status: patent application and granting procedure in general

Free format text: FINAL REJECTION MAILED

STCB Information on status: application discontinuation

Free format text: ABANDONED -- FAILURE TO RESPOND TO AN OFFICE ACTION