WO2006102550A2 - Aluminum alloy - Google Patents
Aluminum alloy Download PDFInfo
- Publication number
- WO2006102550A2 WO2006102550A2 PCT/US2006/010666 US2006010666W WO2006102550A2 WO 2006102550 A2 WO2006102550 A2 WO 2006102550A2 US 2006010666 W US2006010666 W US 2006010666W WO 2006102550 A2 WO2006102550 A2 WO 2006102550A2
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- percent
- aluminum alloy
- cast product
- aluminum
- die cast
- Prior art date
Links
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
- B22D17/00—Pressure die casting or injection die casting, i.e. casting in which the metal is forced into a mould under high pressure
- B22D17/007—Semi-solid pressure die casting
-
- 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
- C22C1/00—Making non-ferrous alloys
- C22C1/12—Making non-ferrous alloys by processing in a semi-solid state, e.g. holding the alloy in the solid-liquid phase
Definitions
- the present invention relates generally to casting alloys. More particularly, the present invention is directed to an aluminum alloy for semi-solid metal (SSM) casting processes.
- SSM semi-solid metal
- SSM aluminum alloy castings outperform, in both cost and performance, other casting techniques, such as conventional die casting, which is performed under high pressure, gravity permanent mold casting and squeeze casting.
- SSM casting methods when utilized for the manufacturing of aluminum alloy products/castings, have proven advantageous over other casting techniques because SSM castings tend to exhibit higher mechanical properties in the areas of strength and ductility and reduced porosity than castings produced by the above- listed other methods.
- Microstructures of SSM aluminum alloy castings reveal the primary phase particles as round crystals that are often referred to as rosettes or globules.
- the primary phase particles in SSM aluminum alloy castings that contain less than twelve percent silicon are comprised of essentially aluminum. Because solid primary phase particles are part of the semi-solid metal being injected into a mold/die cavity, the microstructure of the primary phase of an aluminum alloy prior to injection into a mold/die is indicative of the microstructure of the primary phase of the resulting aluminum alloy casting.
- SSM methods of casting are utilized, the mechanical properties of a casting can be predicted before a casting is even produced. Accordingly, the production of castings with defects can be avoided.
- non-SSM casting processes involve injection/pouring of a molten metal directly into the die.
- the metal is molten, with no parts of the metal being solid, the microstructure of the resulting casting cannot be ascertained until after the molten metal has solidified in the mold/die cavity.
- the microstructure of the primary phase of a casting cannot be predicted before the casting is formed.
- the microstructures of castings prepared by non-SSM casting processes have dendrites.
- Dendrites are "tree-like" structures, and castings with dendrites are prone to microporosity and have inferior mechanical properties than those that exhibit round crystals.
- Thixocasting and Rheocasting are SSM methods of casting. Thixocasting involves the electromagnetic stirring of metal during solidification/freezing to provide aluminum SSM feedstock billets up to approximately 4" in diameter. The stirring action due to the movement of liquid fragments the aluminum dendrites as they form during solidification and results in the formation of small equiaxed grains in the billets.
- the billets are subsequently cut into slugs, and re-heated to a semi-solid state before being injected into the cavity. It is during the billet re-heating stage that the equiaxed aluminum grains undergo globularization. Chemically grain-refined billets are often used in lieu of electromagnetically stirred billets. Heating of grain-refined billets in the semisolid temperature regime also helps yield globular primary phase particles prior to injection into die cavity.
- Rheocasting which is also known as "slurry” or “slurry-on- demand” casting, involves heating a metal to a liquid state, cooling the molten metal to a semi-solid state, and then injecting the semi-solid metal into the die cavity.
- Rheocasting is more efficient than Thixocasting because Rheocasting involves fewer steps than Thixocasting.
- Rheocasting has also proven to be more economically feasible than Thixocasting because any unused scrap metal can be easily re-melted and reprocessed by an SSM component manufacturer.
- the scrap metal With Thixocasting, the scrap metal has to be reformed into billets by the billet manufacturer via the use of electromagnetic stirring or chemical grain refining before being used again.
- Rheocasting requires only that the scrap metal is re-melted and cooled to a semi-solid state before it is injected into a die cavity. As a result, scrap metal can easily be reused with the Rheocasting method of SSM casting and the expense associated with recycling scrap metal is less.
- SSM casting methods utilizing aluminum alloys have been used for manufacturing brake cylinders, fuel rails, engine brackets steering knuckles, suspension links and auto seat backs because, in addition to the above-discussed advantages over non-SSM casting techniques, SSM casting methods offer non-turbulent filling (i.e., less air entrapment), require lower die temperatures, reduce cycle time, reduce shrinkage, and provide the option of heat treatment (Le., solution treatment).
- A356.2 and 357 are the primary aluminum alloys used for SSM castings, including castings of automotive components.
- the chemistries of A356.2 and 357 are as follows:
- A356.2 and 357 when used with SSM casting methods, generate castings of essentially high toughness, i.e., ability to absorb energy before failure, and thus, have been found suitable for automotive components, such as steering knuckles and suspension links.
- the A356.2 and 357 alloys when used with SSM casting methods, have not been found suitable for automotive components that require essentially high strength, i.e., high load bearing ability, such as axle carriers, rack and pinion housings, and steering column housings.
- an aluminum alloy that can be utilized with SSM methods of castings, especially with the increasingly popular Rheocasting method of SSM casting, that can produce high integrity, high-strength automotive components, such as axle carriers, rack and pinion housings, and steering column housings.
- an alloy in accordance with the present invention includes 6.5 to 8.5 percent silicon, 0.60 to 1.0 percent iron, 0.3 to 0.5 percent manganese, 0.35 to 0.65 percent magnesium, 0.01 to 1.0 percent of zinc, 0.11 to 0.2 percent titanium, 2.0 to 2.5 percent copper, and aluminum as the remainder with further one or more other elements 0.001 to 0.15 percent of the weight.
- a die cast product in another exemplary embodiment of the present invention includes 6.5 to 8.5 percent silicon, 0.60 to 1.0 percent iron, 0.3 to 0.5 percent manganese, 0.35 to 0.65 percent magnesium, 0.01 to 1.0 percent of zinc, 0.11 to 0.2 percent titanium, 2.0 to 2.5 percent copper, and aluminum as the remainder with further one or more other elements 0.001 to 0.15 percent of the weight.
- a method of making a die cast product includes forming a semisolid aluminum alloy, wherein the semi-solid aluminum alloy contains 6.5 to 8.5 percent silicon, 0.60 to 1.0 percent iron, 0.3 to 0.5 percent manganese, 0.35 to 0.65 percent magnesium, 0.01 to 1.0 percent of zinc, 0.11 to 0.2 percent titanium, 2.0 to 2.5 percent copper, and aluminum as the remainder with further one or more other elements 0.001 to 0.15 percent of the weight, and placing the semi- solid aluminum alloy in a die cavity.
- FIG. 1 illustrates microstructures of an exemplary embodiment an aluminum alloy in accordance with the present invention.
- FIG.2 illustrates microstructures of an exemplary embodiment of an aluminum alloy in accordance with the present invention.
- FIG. 3 illustrates microstructures of an exemplary embodiment of an aluminum alloy in accordance with the present invention.
- An aluminum alloy in accordance with the present invention is a high copper, manganese and iron (HiCMF) aluminum alloy.
- HiCMF high copper, manganese and iron
- an aluminum alloy in accordance with the present invention is composed of the below-listed elements, by percentage of weight, as follows:
- the "others" are lead and/or chromium.
- the amount of manganese is more preferably 0.30 to 0.50 percent by weight.
- the ranges of manganese as described herein facilitate a reduction in the amount of solder when adhering the aluminum alloy to die steel. Furthermore, the ranges described herein contribute to the formation of 'Chinese- script' intermetallics and are therefore less detrimental to ductility of the aluminum alloy. Particular examples of preferred amounts of manganese include 0.30, 0.35, and 0.45 percent by weight.
- Preferred amounts of zinc include 0.01 to 1.00 percent by weight.
- the range of zinc described herein facilitates minimizing or substantially eliminating 'hot cracking' of the aluminum alloy during solidification.
- Particular examples of preferred amounts of zinc include 0.01, 0.03, 0.05, and 0.08 percent by weight.
- Preferred amounts of titanium include 0.11 to 0.20 percent by weight.
- the range of titanium described herein promotes effective grain refinement and thereby generally contributes to increased mechanical properties. More particularly, toughness is increased by effective grain refinement.
- Particular examples of preferred amounts of titanium include 0.11, 0.15, 0.18, 0.19, and 0.20 percent by weight.
- the response to artificial aging is unexpectedly improved.
- the response to artificial aging following solution treatment is unexpectedly improved by including 0.001 to 0.10 percent tin by weight.
- Particular examples of preferred amounts of tin include 0.003, 0.045, and 0.09 percent by weight.
- Preferred amounts of chromium include 0.001 to 0.10 percent by weight.
- the range of chromium described herein facilitates a reduction or substantially eliminates sludge formation in the aluminum alloy.
- the term, 'sludge' as used herein refers to a complex of essentially iron, chromium and manganese.
- Particular examples of preferred amounts of chromium include 0.003, 0.04, and 0.09 percent by weight.
- An aluminum alloy in accordance with the present invention is suitable for SSM methods of casting because the microstructure of the primary aluminum phase of the metal slurry prior to its injection into a die cavity is comprised of globular and/or rosette crystals.
- An alloy in accordance with the present invention is hypoeutectic because its silicon content is less than 12 percent.
- the primary phase metal of an alloy in accordance with the present invention is aluminum.
- Alloys with silicon composing less than twelve percent of their weight are hypoeutectic and alloys with silicon composing more than twelve percent of their weight are hypereutectic.
- FIG. 1 and FIG. 2 shown are microstructures of the primary phase from various locations of an aluminum alloy in accordance with the present invention prior to its injection into a die cavity.
- the illustrations of FIG. 1 and FIG. 2 were ascertained in accordance with the conventional evaluation method of "water-quenching," which "locks in” the microstructure.
- the microstructures of FIG. 1, from top to bottom, are from the middle edge 10, middle 12 and center 14 of a water-quenched slug. It can be seen from FIG. 1 that the primary aluminum phase particles consist of round crystal/globular 16, and/or rosette 18 formations.
- FIG. 2 depicts microstructures of the primary phase of an aluminum alloy in accordance with the present invention prior to its injection into a die cavity.
- the microstructures of FIG.2, from top to bottom, are from the bottom edge 20, middle 22 and center 24 of a water-quenched slug.
- the primary aluminum phase particles of an aluminum alloy in accordance with the present invention consist of round crystal/globular 26 and/or rosette 28 formations.
- FIG. 3 depicts microstructures of the primary phase of an aluminum alloy in accordance with the present invention after it has been injected into a die cavity.
- the primary aluminum phase particles of an aluminum alloy in accordance with the present invention consist of round crystals/globular 32 and/or rosette 34 formations.
- FIG. 1 and FIG. 2 are compared with FIG. 3, it can be seen that the morphology of the primary aluminum phase prior to injection into a die cavity is similar to that of the aluminum alloy in the resulting casting.
- the microstructure of the primary phase of an alloy in accordance with the present invention can be determined before it is utilized to form a casting. Thus, the number of casts with microstructures unsuitable for their purpose can be reduced.
- silicon is restricted to 7.2 percent to 8 percent of the weight to efficiently achieve formation of the primary aluminum phase during the cooling of the molten metal to the semi-solid state.
- the amount of silicon present in an aluminum alloy may be directly related to the strength of the aluminum alloy.
- the higher the content of silicon the higher the strength of the aluminum alloy.
- the average silicon content of the alloy is higher than other alloys, such as the A356.2 and 357 aluminum alloys.
- the strength of an aluminum alloy in accordance with the present invention is higher than other alloys, such as A 3562.2 and 357.
- an aluminum alloy in accordance with the present invention reveals the presence of fine aluminum-silicon eutectic and entrapped intermetallic particles 30 within the round crystals, globular and/or rosette primary aluminum phase.
- the entrapped intermetallic particles 30 essentially consist of iron, silicon and manganese.
- a path fracture path
- the intermetallic particles 30 are entrapped within the round crystal/globular 32 and/or rosette 34 structures, the fracture path is now restricted. Accordingly, fractures occur with less frequency, especially when an aluminum alloy in accordance with the present invention is compared to the A356.2 and 357 aluminum alloys that do not reveal entrapped particles in their microstructures in the primary aluminum phase.
- the formation of the intermetallic particles in an aluminum alloy in accordance with the present invention can be attributed to the high content of iron in the aluminum alloy.
- iron is 0.6 to 1.0 percent of the weight.
- iron is 0.6 to 0.8 percent of the weight.
- the iron content of an aluminum alloy in accordance with the present invention is higher than other alloys, such as A 356.2 and 357 which are, at a maximum, 0.12 percent of the weight. Accordingly, an alloy in accordance with the present invention is less expensive than A 356.2 and 357 because the iron content does not have to be maintained low. Additionally, because the iron content is not low, the potential of soldering is reduced.
- magnesium is approximately 0.35 to 0.65 percent of the weight.
- the magnesium content of an aluminum alloy in accordance with the present invention is higher than the magnesium content of other aluminum alloys, such as the A 356.2 and 357, which is 0.30 to 0.45 and 0.45 to 0.6 percent of the weight, respectively.
- the strength of a casting made from an aluminum alloy in accordance with the present invention will be even greater after the alloy has been heat treated, i.e., subjected to a solution treatment and artificially aged.
- the magnesium content is approximately 0.45 to 0.6 percent of the weight.
- an aluminum alloy in accordance with the present invention is suitable for the manufacturing of products that require high strength, such as axle carriers, rack and pinion housings and steering column housings by both Rheocasting and Thixocasting.
Abstract
An aluminum alloy is disclosed that includes 6.5 to 8.5 percent silicon, 0.6 to 1.0 percent iron, 0.3 to 0.5 percent manganese, 0.35 to 0.65 percent magnesium, 0.01 to 1.0 percent zinc, 0.11 to 0.2 percent titanium, 2.0 to 2.5 percent copper, and aluminum as the remainder with further one or more other elements that are 0.001 to 0.15 percent of the weight of the aluminum alloy. An aluminum alloy of the above composition is high in strength and suitable for use with SSM methods of casting, such as Rheocasting and Thixocasting.
Description
ALUMINUM ALLOY
PRIORITY
The present application claims priority from United States Patent Application entitled, Aluminum Alloy, filed March 19, 2002, having serial number 10/100,053, the disclosure of which is hereby incorporated by reference .
FIELD OF THE INVENTION
[0001] The present invention relates generally to casting alloys. More particularly, the present invention is directed to an aluminum alloy for semi-solid metal (SSM) casting processes.
BACKGROUND OF THE INVENTION
[0002] SSM aluminum alloy castings outperform, in both cost and performance, other casting techniques, such as conventional die casting, which is performed under high pressure, gravity permanent mold casting and squeeze casting. SSM casting methods, when utilized for the manufacturing of aluminum alloy products/castings, have proven advantageous over other casting techniques because SSM castings tend to exhibit higher mechanical properties in the areas of strength and ductility and reduced porosity than castings produced by the above- listed other methods.
[0003] Microstructures of SSM aluminum alloy castings reveal the primary phase particles as round crystals that are often referred to as rosettes or
globules. The primary phase particles in SSM aluminum alloy castings that contain less than twelve percent silicon are comprised of essentially aluminum. Because solid primary phase particles are part of the semi-solid metal being injected into a mold/die cavity, the microstructure of the primary phase of an aluminum alloy prior to injection into a mold/die is indicative of the microstructure of the primary phase of the resulting aluminum alloy casting. Thus, when SSM methods of casting are utilized, the mechanical properties of a casting can be predicted before a casting is even produced. Accordingly, the production of castings with defects can be avoided.
[0004] Unlike SSM methods of casting, non-SSM casting processes involve injection/pouring of a molten metal directly into the die. Thus, because the metal is molten, with no parts of the metal being solid, the microstructure of the resulting casting cannot be ascertained until after the molten metal has solidified in the mold/die cavity. Thus, with non-SSM casting processes the microstructure of the primary phase of a casting cannot be predicted before the casting is formed.
[0005] Typically, the microstructures of castings prepared by non-SSM casting processes have dendrites. Dendrites are "tree-like" structures, and castings with dendrites are prone to microporosity and have inferior mechanical properties than those that exhibit round crystals.
[0006] Thixocasting and Rheocasting are SSM methods of casting. Thixocasting involves the electromagnetic stirring of metal during solidification/freezing to provide aluminum SSM feedstock billets up to approximately 4" in diameter. The stirring action due to the movement of liquid fragments the aluminum dendrites as they form during solidification and results in the formation of small equiaxed grains in the billets. The billets are subsequently cut into slugs, and re-heated to a semi-solid state before being injected into the cavity. It is during the billet re-heating stage that the equiaxed aluminum grains undergo globularization. Chemically grain-refined billets are often used in lieu of electromagnetically stirred billets. Heating of grain-refined billets in the semisolid temperature regime also helps yield globular primary phase particles prior to injection into die cavity.
[0007] Rheocasting, which is also known as "slurry" or "slurry-on- demand" casting, involves heating a metal to a liquid state, cooling the molten metal to a semi-solid state, and then injecting the semi-solid metal into the die cavity. Rheocasting is more efficient than Thixocasting because Rheocasting involves fewer steps than Thixocasting.
[0008] Rheocasting has also proven to be more economically feasible than Thixocasting because any unused scrap metal can be easily re-melted and reprocessed by an SSM component manufacturer. With Thixocasting, the scrap
metal has to be reformed into billets by the billet manufacturer via the use of electromagnetic stirring or chemical grain refining before being used again. However, unlike Thixocasting, Rheocasting requires only that the scrap metal is re-melted and cooled to a semi-solid state before it is injected into a die cavity. As a result, scrap metal can easily be reused with the Rheocasting method of SSM casting and the expense associated with recycling scrap metal is less.
[0009] In recent years, SSM casting methods utilizing aluminum alloys have been used for manufacturing brake cylinders, fuel rails, engine brackets steering knuckles, suspension links and auto seat backs because, in addition to the above-discussed advantages over non-SSM casting techniques, SSM casting methods offer non-turbulent filling (i.e., less air entrapment), require lower die temperatures, reduce cycle time, reduce shrinkage, and provide the option of heat treatment (Le., solution treatment).
[0010] Among the various casting alloys in use, A356.2 and 357 are the primary aluminum alloys used for SSM castings, including castings of automotive components. The chemistries of A356.2 and 357 are as follows:
A356.2 357
Element Percent of Element Percent of Weight Weight
Silicon 6.5-7.5 Silicon 6.5-7.5
Iron 0.12 max Iron 0.12 max
Manganese 0.05 max Manganese 0.03 max
Magnesium 0.30 - 0.45 Magnesium 0.45 - 0.6
Zinc 0.50 max Zinc 0.05 max
Titanium 0.20 max Titanium 0.20 max
Copper 0.10 max Copper 0.03 max
Others 0.15 total Others 0.15 total
Aluminum Balance Aluminum Balance
[0011] A356.2 and 357, when used with SSM casting methods, generate castings of essentially high toughness, i.e., ability to absorb energy before failure, and thus, have been found suitable for automotive components, such as steering knuckles and suspension links.
[0012] However, the A356.2 and 357 alloys, when used with SSM casting methods, have not been found suitable for automotive components that require essentially high strength, i.e., high load bearing ability, such as axle carriers, rack
and pinion housings, and steering column housings.
[0013] There are, however, problems associated with the use of A356.2 and 357 aluminum alloys. Maintaining low percentages of iron, copper and zinc increases the cost of the A356.2 and 357 aluminum alloys. By keeping the iron content low, there is also the potential that soldering will occur during the casting process. Soldering refers to the phenomenon that takes place when aluminum adheres to the die cavity during the die casting process. Soldering occurrences often lead to defective castings.
[0014] Accordingly, it is desirable to provide an aluminum alloy that can be utilized with SSM methods of castings, especially with the increasingly popular Rheocasting method of SSM casting, that can produce high integrity, high-strength automotive components, such as axle carriers, rack and pinion housings, and steering column housings.
[0015] Further, it is desirable to provide an aluminum alloy that is less prone to the soldering phenomenon.
[0016] It is also desirable to provide an alloy that is less expensive to produce than other alloys such as A 356.2 and 357.
SUMMARY OF THE INVENTION
[0017] In an exemplary embodiment of the present invention, an alloy in accordance with the present invention is provided that includes 6.5 to 8.5 percent silicon, 0.60 to 1.0 percent iron, 0.3 to 0.5 percent manganese, 0.35 to 0.65 percent magnesium, 0.01 to 1.0 percent of zinc, 0.11 to 0.2 percent titanium, 2.0 to 2.5 percent copper, and aluminum as the remainder with further one or more other elements 0.001 to 0.15 percent of the weight.
[0018] In another exemplary embodiment of the present invention a die cast product is provided that includes 6.5 to 8.5 percent silicon, 0.60 to 1.0 percent iron, 0.3 to 0.5 percent manganese, 0.35 to 0.65 percent magnesium, 0.01 to 1.0 percent of zinc, 0.11 to 0.2 percent titanium, 2.0 to 2.5 percent copper, and aluminum as the remainder with further one or more other elements 0.001 to 0.15 percent of the weight.
[0019] In yet another exemplary embodiment of the present invention a method of making a die cast product is provided that includes forming a semisolid aluminum alloy, wherein the semi-solid aluminum alloy contains 6.5 to 8.5 percent silicon, 0.60 to 1.0 percent iron, 0.3 to 0.5 percent manganese, 0.35 to 0.65 percent magnesium, 0.01 to 1.0 percent of zinc, 0.11 to 0.2 percent titanium, 2.0 to 2.5 percent copper, and aluminum as the remainder with further one or more other elements 0.001 to 0.15 percent of the weight, and placing the semi-
solid aluminum alloy in a die cavity.
[0020] There has thus been outlined, rather broadly, the more important features of the invention in order that the detailed description thereof that follows may be better understood, and in order that the present contribution to the art may be better appreciated. There are, of course, additional features of the invention that will be described below and which will form the subject matter of the claims appended hereto.
[0021] In this respect, before explaining at least one embodiment of the invention in detail, it is to be understood that the invention is not limited in its application to the details of construction and to the arrangements of the components set forth in the following description or illustrated in the drawings. The invention is capable of other embodiments and of being practiced and carried out in various ways. Also, it is to be understood that the phraseology and terminology employed herein, as well as the abstract, are for the purpose of description and should not be regarded as limiting.
[0022] As such, those skilled in the art will appreciate that the conception upon which this disclosure is based may readily be utilized as a basis for the designing of other structures, methods and systems for carrying out the several purposes of the present invention. It is important, therefore, that the claims be regarded as including such equivalent constructions insofar as they do not depart
from the spirit and scope of the present invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0023] FIG. 1 illustrates microstructures of an exemplary embodiment an aluminum alloy in accordance with the present invention.
[0024] FIG.2 illustrates microstructures of an exemplary embodiment of an aluminum alloy in accordance with the present invention.
[0025] FIG. 3 illustrates microstructures of an exemplary embodiment of an aluminum alloy in accordance with the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS OF THE INVENTION
[0026] An aluminum alloy in accordance with the present invention is a high copper, manganese and iron (HiCMF) aluminum alloy. In an exemplary embodiment of the present invention, an aluminum alloy in accordance with the present invention, is composed of the below-listed elements, by percentage of weight, as follows:
[0027] In a preferred embodiment of the present invention, the "others" are lead and/or chromium.
[0028] In addition, the amount of manganese is more preferably 0.30 to 0.50 percent by weight. The ranges of manganese as described herein facilitate a reduction in the amount of solder when adhering the aluminum alloy to die steel. Furthermore, the ranges described herein contribute to the formation of 'Chinese- script' intermetallics and are therefore less detrimental to ductility of the aluminum alloy. Particular examples of preferred amounts of manganese include 0.30, 0.35, and 0.45 percent by weight.
[0029] Preferred amounts of zinc include 0.01 to 1.00 percent by weight. The range of zinc described herein facilitates minimizing or substantially eliminating 'hot cracking' of the aluminum alloy during solidification. Particular examples of preferred amounts of zinc include 0.01, 0.03, 0.05, and 0.08 percent
by weight.
[0030] Preferred amounts of titanium include 0.11 to 0.20 percent by weight. The range of titanium described herein promotes effective grain refinement and thereby generally contributes to increased mechanical properties. More particularly, toughness is increased by effective grain refinement. Particular examples of preferred amounts of titanium include 0.11, 0.15, 0.18, 0.19, and 0.20 percent by weight.
[0031] It is a benefit of the aluminum alloy having 0.001 to 0.10 percent tin by weight that the response to artificial aging is unexpectedly improved. In particular, the response to artificial aging following solution treatment is unexpectedly improved by including 0.001 to 0.10 percent tin by weight. Particular examples of preferred amounts of tin include 0.003, 0.045, and 0.09 percent by weight.
[0032] Preferred amounts of chromium include 0.001 to 0.10 percent by weight. The range of chromium described herein facilitates a reduction or substantially eliminates sludge formation in the aluminum alloy. The term, 'sludge' as used herein refers to a complex of essentially iron, chromium and manganese. Particular examples of preferred amounts of chromium include 0.003, 0.04, and 0.09 percent by weight.
[0033] It is an unexpected benefit of the aluminum alloy having 0.001 to
0.10 percent lead by weight that machinability is improved while essentially eliminating "hot shortness" e.g., brittleness at elevated temperatures. In this regard, higher lead content generally increases machinability. On the other hand, increased lead content also contributes to segregation of the element during casting and cause hot shortness. Particular examples of preferred amounts of lead include 0.003, 0.06, and 0.09 percent by weight.
[0034] An aluminum alloy in accordance with the present invention is suitable for SSM methods of casting because the microstructure of the primary aluminum phase of the metal slurry prior to its injection into a die cavity is comprised of globular and/or rosette crystals.
[0035] An alloy in accordance with the present invention is hypoeutectic because its silicon content is less than 12 percent. The primary phase metal of an alloy in accordance with the present invention is aluminum.
[0036] Alloys with silicon composing less than twelve percent of their weight are hypoeutectic and alloys with silicon composing more than twelve percent of their weight are hypereutectic.
[0037] Referring to FIG. 1 and FIG. 2, shown are microstructures of the primary phase from various locations of an aluminum alloy in accordance with the present invention prior to its injection into a die cavity. The illustrations of FIG. 1 and FIG. 2 were ascertained in accordance with the conventional evaluation method of "water-quenching," which "locks in" the microstructure. The microstructures of FIG. 1, from top to bottom, are from the middle edge 10, middle 12 and center 14 of a water-quenched slug. It can be seen from FIG. 1 that the primary aluminum phase particles consist of round crystal/globular 16, and/or rosette 18 formations.
[0038] FIG. 2 depicts microstructures of the primary phase of an aluminum alloy in accordance with the present invention prior to its injection into a die cavity. The microstructures of FIG.2, from top to bottom, are from the bottom edge 20, middle 22 and center 24 of a water-quenched slug. It can be seen from FIG. 2 that the primary aluminum phase particles of an aluminum alloy in accordance with the present invention consist of round crystal/globular 26 and/or rosette 28 formations.
[0039] FIG. 3 depicts microstructures of the primary phase of an aluminum alloy in accordance with the present invention after it has been injected into a die cavity. It can be seen from FIG. 3 that the primary aluminum phase particles of an aluminum alloy in accordance with the present invention consist of
round crystals/globular 32 and/or rosette 34 formations. Thus, when FIG. 1 and FIG. 2 are compared with FIG. 3, it can be seen that the morphology of the primary aluminum phase prior to injection into a die cavity is similar to that of the aluminum alloy in the resulting casting. Accordingly, the microstructure of the primary phase of an alloy in accordance with the present invention can be determined before it is utilized to form a casting. Thus, the number of casts with microstructures unsuitable for their purpose can be reduced.
[0040] In an exemplary embodiment of the present invention silicon is restricted to 7.2 percent to 8 percent of the weight to efficiently achieve formation of the primary aluminum phase during the cooling of the molten metal to the semi-solid state.
[0041] Additionally, the amount of silicon present in an aluminum alloy may be directly related to the strength of the aluminum alloy. Typically, the higher the content of silicon, the higher the strength of the aluminum alloy. In exemplary embodiments of the present invention, the average silicon content of the alloy is higher than other alloys, such as the A356.2 and 357 aluminum alloys. Accordingly, the strength of an aluminum alloy in accordance with the present invention is higher than other alloys, such as A 3562.2 and 357.
[0042] Further, as shown in FIG.3, an aluminum alloy in accordance with the present invention reveals the presence of fine aluminum-silicon eutectic and
entrapped intermetallic particles 30 within the round crystals, globular and/or rosette primary aluminum phase. The entrapped intermetallic particles 30 essentially consist of iron, silicon and manganese.
[0043] Typically, the formation of the intermetallic particles 30, such as those shown in FIG. 3, lead to fractures that travel along a path (fracture path) within the structure of the casting. However, because the intermetallic particles 30 are entrapped within the round crystal/globular 32 and/or rosette 34 structures, the fracture path is now restricted. Accordingly, fractures occur with less frequency, especially when an aluminum alloy in accordance with the present invention is compared to the A356.2 and 357 aluminum alloys that do not reveal entrapped particles in their microstructures in the primary aluminum phase.
[0044] The formation of the intermetallic particles in an aluminum alloy in accordance with the present invention can be attributed to the high content of iron in the aluminum alloy. In an exemplary embodiment of the present invention, iron is 0.6 to 1.0 percent of the weight. In another exemplary embodiment of the present invention iron is 0.6 to 0.8 percent of the weight. The iron content of an aluminum alloy in accordance with the present invention is higher than other alloys, such as A 356.2 and 357 which are, at a maximum, 0.12 percent of the weight. Accordingly, an alloy in accordance with the present invention is less expensive than A 356.2 and 357 because the iron content does
not have to be maintained low. Additionally, because the iron content is not low, the potential of soldering is reduced.
[0045] In an exemplary embodiment of the present invention, magnesium is approximately 0.35 to 0.65 percent of the weight. The magnesium content of an aluminum alloy in accordance with the present invention is higher than the magnesium content of other aluminum alloys, such as the A 356.2 and 357, which is 0.30 to 0.45 and 0.45 to 0.6 percent of the weight, respectively. The strength of a casting made from an aluminum alloy in accordance with the present invention will be even greater after the alloy has been heat treated, i.e., subjected to a solution treatment and artificially aged. In a preferred embodiment of an aluminum alloy in accordance with the present invention, the magnesium content is approximately 0.45 to 0.6 percent of the weight.
[0046] As a result of its high strength, an aluminum alloy in accordance with the present invention is suitable for the manufacturing of products that require high strength, such as axle carriers, rack and pinion housings and steering column housings by both Rheocasting and Thixocasting.
[0047] The many features and advantages of the invention are apparent from the detailed specification, and thus, it is intended by the appended claims to cover all such features and advantages of the invention which fall within the true spirit and scope of the invention. Further, since numerous modifications and
variations will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation illustrated and described, and accordingly, all suitable modifications and equivalents may be resorted to as falling within the scope of the invention.
Claims
CLAIMS What is claimed is:
1. An aluminum alloy, consisting essentially of the following constituents by percentage of weight:
6.5 to 8.5 percent silicon;
0.6 to 1.0 percent iron;
0.3 to 0.5 percent manganese;
0.35 to 0.65 percent magnesium;
0.01 to 1.0 percent zinc;
0.11 to 0.2 percent titanium;
2.0 to 2.5 percent copper;
0.001 to 0.15 percent one or more other elements; and aluminum as the remainder.
2. The aluminum alloy of claim 1 , wherein the aluminum alloy comprises 7.2 to 8 percent silicon.
3. The aluminum alloyofclaim l, wherein the aluminum alloy comprises to 0.6 to 0.8 percent iron.
4. The aluminum alloy of claim 1 , wherein the aluminum alloy comprises 0.45 to 0.6 percent magnesium.
5. The aluminum alloy of claim 1 , wherein the one or more other elements is lead.
6. The aluminum alloy of claim 1, wherein the one or more other elements is chromium.
7. The aluminum alloy of claim 1 , wherein the one or more other elements are lead and chromium.
8. A die cast product, comprising by percentage of weight: 6.5 to 8.5 percent silicon;
0.6 to 1.0 percent iron;
0.3 to 0.5 percent manganese;
0.35 to 0.65 percent magnesium;
0.01 to 1.0 percent zinc;
0.11 to 0.2 percent titanium;
2.0 to 2.5 percent copper;
0.001 to 0.15 percent one or more other elements; and aluminum as the remainder.
9. The die cast product, of claim 8, wherein the die cast product comprises 7.2 to 8 percent silicon.
10. The die cast product of claim 8, wherein the die cast product comprises 0.6 to 0.8 percent iron.
11. The die cast product of claim 8, wherein the die cast product comprises 0.45 to 0.6 percent magnesium.
12. The die cast product of claim 8, wherein the one or more other elements is lead.
13. The die cast product of claim 8, wherein the one or more other elements is chromium.
14. The die cast product of claim 8, wherein the one or more other elements are lead and chromium.
15. A method of making a die cast product by an SSM method of casting, comprising: forming a semi-solid aluminum alloy, wherein the semi-solid aluminum alloy comprises by percentage of weight:
6.5 to 8.5 percent silicon;
0.6 to 1.0 percent iron;
0.3 to 0.5 percent manganese;
0.35 to 0.65 percent magnesium;
0.01 to 1.0 percent zinc;
0.11 to 0.2 percent titanium;
2.0 to 2.5 percent copper;
0.001 to 0.15 percent one or more other elements; and aluminum as the remainder. placing the aluminum alloy in a die cavity.
16. The method of making the die cast product of claim 15, wherein the one or more other element is lead.
17. The method of making the die cast product of claim 15, wherein the one or more other element is chromium.
18. The method of making the die cast product of claim 17, wherein the one or more other elements are lead and chromium.
19. The method of making the die cast product of claim 15, wherein the SSM method of casting is Rheocasting.
20. The method of making the die cast product of claim 15, wherein the SSM method of casting is Thixocasting.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
EP06739457A EP1871555A4 (en) | 2005-03-22 | 2006-03-22 | Aluminum alloy |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US11/085,086 US20050161128A1 (en) | 2002-03-19 | 2005-03-22 | Aluminum alloy |
US11/085,086 | 2005-03-22 |
Publications (2)
Publication Number | Publication Date |
---|---|
WO2006102550A2 true WO2006102550A2 (en) | 2006-09-28 |
WO2006102550A3 WO2006102550A3 (en) | 2007-11-08 |
Family
ID=37024653
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/US2006/010666 WO2006102550A2 (en) | 2005-03-22 | 2006-03-22 | Aluminum alloy |
Country Status (3)
Country | Link |
---|---|
US (1) | US20050161128A1 (en) |
EP (1) | EP1871555A4 (en) |
WO (1) | WO2006102550A2 (en) |
Cited By (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP2865772A1 (en) * | 2013-10-23 | 2015-04-29 | Befesa Aluminio, S.L. | Aluminium casting alloy |
CN108149083A (en) * | 2016-12-02 | 2018-06-12 | 比亚迪股份有限公司 | A kind of semisolid pressure casting aluminium alloy and the method for preparing semisolid pressure casting aluminium alloy castings |
DE102019205267B3 (en) * | 2019-04-11 | 2020-09-03 | Audi Ag | Die-cast aluminum alloy |
Families Citing this family (8)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US7625454B2 (en) * | 2004-07-28 | 2009-12-01 | Alcoa Inc. | Al-Si-Mg-Zn-Cu alloy for aerospace and automotive castings |
US20060177688A1 (en) * | 2005-02-04 | 2006-08-10 | Corus Aluminium Walzprodukte Gmbh | Aluminium alloy brazing material |
US8083871B2 (en) | 2005-10-28 | 2011-12-27 | Automotive Casting Technology, Inc. | High crashworthiness Al-Si-Mg alloy and methods for producing automotive casting |
CN103451484A (en) * | 2012-06-01 | 2013-12-18 | 上海万泰铝业有限公司 | Casting aluminium-silicon alloy for cylinder body of automobile engine |
CN104195382A (en) * | 2014-08-28 | 2014-12-10 | 南京赛达机械制造有限公司 | Impact-resistant aluminum alloy for steam turbine blade and thermal treatment process of impact-resistant aluminum alloy |
EP3334850A4 (en) | 2015-08-13 | 2019-03-13 | Alcoa USA Corp. | Improved 3xx aluminum casting alloys, and methods for making the same |
CN106870333B (en) * | 2017-01-24 | 2021-10-19 | 广东美芝制冷设备有限公司 | Electric compressor and refrigeration equipment |
KR101955993B1 (en) * | 2017-02-17 | 2019-03-08 | 주식회사 지.에이.엠 | High strength aluminium alloy and high strength aluminium alloy casting |
Family Cites Families (15)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3314829A (en) * | 1964-01-13 | 1967-04-18 | Aluminium Lab Ltd | High strength pressure die casting alloy |
US3480465A (en) * | 1966-03-30 | 1969-11-25 | Shichiro Ohshima | Method of chemically bonding aluminum or aluminum alloys to ferrous alloys |
CA1235048A (en) * | 1983-05-23 | 1988-04-12 | Yoji Awano | Method for producing aluminum alloy castings and the resulting product |
JP2506115B2 (en) * | 1987-07-11 | 1996-06-12 | 株式会社豊田自動織機製作所 | High-strength, wear-resistant aluminum alloy with good shear cutability and its manufacturing method |
JP3328356B2 (en) * | 1993-03-19 | 2002-09-24 | 本田技研工業株式会社 | Aluminum alloy material for casting |
US5858131A (en) * | 1994-11-02 | 1999-01-12 | Tsuyoshi Masumoto | High strength and high rigidity aluminum-based alloy and production method therefor |
DE19524564A1 (en) * | 1995-06-28 | 1997-01-02 | Vaw Alucast Gmbh | Aluminium@ alloy for casting cylinder heads |
JP3725279B2 (en) * | 1997-02-20 | 2005-12-07 | Ykk株式会社 | High strength, high ductility aluminum alloy |
EP0911420B1 (en) * | 1997-10-08 | 2002-04-24 | ALUMINIUM RHEINFELDEN GmbH | Aluminium casting alloy |
JPH11286758A (en) * | 1998-04-02 | 1999-10-19 | Nippon Light Metal Co Ltd | Production of forged product using aluminum casting material |
EP0992600B1 (en) * | 1998-10-09 | 2002-09-04 | Honda Giken Kogyo Kabushiki Kaisha | Aluminum alloy for die-cast product having a high toughness |
EP1118685A1 (en) * | 2000-01-19 | 2001-07-25 | ALUMINIUM RHEINFELDEN GmbH | Aluminium cast alloy |
US6342180B1 (en) * | 2000-06-05 | 2002-01-29 | Noranda, Inc. | Magnesium-based casting alloys having improved elevated temperature properties |
DE10206035A1 (en) * | 2002-02-14 | 2003-08-28 | Ks Kolbenschmidt Gmbh | Aluminum-based alloy used in the production of a piston for use in an internal combustion engine contains alloying additions of silicon, magnesium, vanadium and beryllium |
US6908590B2 (en) * | 2002-03-19 | 2005-06-21 | Spx Corporation | Aluminum alloy |
-
2005
- 2005-03-22 US US11/085,086 patent/US20050161128A1/en not_active Abandoned
-
2006
- 2006-03-22 WO PCT/US2006/010666 patent/WO2006102550A2/en active Application Filing
- 2006-03-22 EP EP06739457A patent/EP1871555A4/en not_active Withdrawn
Non-Patent Citations (1)
Title |
---|
See references of EP1871555A4 * |
Cited By (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP2865772A1 (en) * | 2013-10-23 | 2015-04-29 | Befesa Aluminio, S.L. | Aluminium casting alloy |
CN108149083A (en) * | 2016-12-02 | 2018-06-12 | 比亚迪股份有限公司 | A kind of semisolid pressure casting aluminium alloy and the method for preparing semisolid pressure casting aluminium alloy castings |
DE102019205267B3 (en) * | 2019-04-11 | 2020-09-03 | Audi Ag | Die-cast aluminum alloy |
Also Published As
Publication number | Publication date |
---|---|
WO2006102550A3 (en) | 2007-11-08 |
EP1871555A4 (en) | 2010-08-18 |
EP1871555A2 (en) | 2008-01-02 |
US20050161128A1 (en) | 2005-07-28 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
US6908590B2 (en) | Aluminum alloy | |
WO2006102550A2 (en) | Aluminum alloy | |
Kleiner et al. | Microstructure and mechanical properties of squeeze cast and semi-solid cast Mg–Al alloys | |
Birol | Cooling slope casting and thixoforming of hypereutectic A390 alloy | |
AU2005269483B2 (en) | An Al-Si-Mg-Zn-Cu alloy for aerospace and automotive castings | |
US9322086B2 (en) | Aluminum pressure casting alloy | |
US9771635B2 (en) | Cast aluminum alloy for structural components | |
EP2110452A1 (en) | High strength L12 aluminium alloys | |
EP2112242A1 (en) | Heat treatable L12 aluminium alloys | |
CN109072356B (en) | Die casting alloy | |
JP4765400B2 (en) | Aluminum alloy for semi-solid casting, aluminum alloy casting and manufacturing method thereof | |
EP2110453A1 (en) | L12 Aluminium alloys | |
AU2005238478A1 (en) | Heat treatable AL-ZN-MG alloy for aerospace and automotive castings | |
Afshari et al. | Effects of pre-deformation on microstructure and tensile properties of Al—Zn—Mg—Cu alloy produced by modified strain induced melt activation | |
GB2553366A (en) | A casting alloy | |
WO2018161311A1 (en) | Aluminum alloys | |
US20220017997A1 (en) | Aluminum alloys for structural high pressure vacuum die casting applications | |
CN111101031B (en) | Al-Mg2Si-Mg-Mn-Y-B high-strength and high-toughness aluminum alloy and preparation method thereof | |
JP2000054047A (en) | HYPO-EUTECTIC ALUMINUM-SILICON ALLOY IN WHICH PRIMARY CRYSTAL Si IS CRYSTALLIZED OUT AND PRODUCTION THEREOF | |
WO2016145644A1 (en) | Alloy composition | |
WO1998038347A1 (en) | Foundry alloy | |
US6719859B2 (en) | High strength aluminum base alloy | |
US10086429B2 (en) | Chilled-zone microstructures for cast parts made with lightweight metal alloys | |
EP2010685A2 (en) | Squeeze cast rear suspension components using adc12-t4 aluminum alloy | |
CN110527873B (en) | Al-Si-Mg-Ti-N-Sc alloy for chassis subframe and preparation method thereof |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
121 | Ep: the epo has been informed by wipo that ep was designated in this application | ||
NENP | Non-entry into the national phase |
Ref country code: DE |
|
NENP | Non-entry into the national phase |
Ref country code: RU |
|
WWE | Wipo information: entry into national phase |
Ref document number: 2006739457 Country of ref document: EP |