EP3669011A1 - Method of forming a cast aluminium alloy - Google Patents

Method of forming a cast aluminium alloy

Info

Publication number
EP3669011A1
EP3669011A1 EP18765965.1A EP18765965A EP3669011A1 EP 3669011 A1 EP3669011 A1 EP 3669011A1 EP 18765965 A EP18765965 A EP 18765965A EP 3669011 A1 EP3669011 A1 EP 3669011A1
Authority
EP
European Patent Office
Prior art keywords
alloy
melt
castings
alloys
less
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.)
Pending
Application number
EP18765965.1A
Other languages
German (de)
French (fr)
Inventor
Shouxun Ji
Xixi DONG
Yijie ZHANG
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.)
Brunel University London
Original Assignee
Brunel University London
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 Brunel University London filed Critical Brunel University London
Publication of EP3669011A1 publication Critical patent/EP3669011A1/en
Pending legal-status Critical Current

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
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C21/00—Alloys based on aluminium
    • C22C21/02—Alloys based on aluminium with silicon as the next major constituent
    • C22C21/04—Modified aluminium-silicon alloys
    • 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
    • C22C1/02—Making non-ferrous alloys by melting
    • C22C1/026—Alloys based on aluminium
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C3/00—Removing material from alloys to produce alloys of different constitution separation of the constituents of alloys
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22F—CHANGING THE PHYSICAL STRUCTURE OF NON-FERROUS METALS AND NON-FERROUS ALLOYS
    • C22F1/00—Changing the physical structure of non-ferrous metals or alloys by heat treatment or by hot or cold working
    • C22F1/04—Changing the physical structure of non-ferrous metals or alloys by heat treatment or by hot or cold working of aluminium or alloys based thereon
    • C22F1/043—Changing the physical structure of non-ferrous metals or alloys by heat treatment or by hot or cold working of aluminium or alloys based thereon of alloys with silicon as the next major constituent

Definitions

  • the present invention generally relates to a method of forming a cast aluminium alloy, and in particular aluminum castings for enhanced mechanical properties in structural applications.
  • the castings When utilized to make shape aluminium alloy castings with gravity casting process, the castings have achieved a 0.2 % offset yield strength of greater than 310 MPa, an ultimate tensile strength of greater than 365 MPa, and an elongation of greater than 10 %. More specifically, the excellent strength and ductility properties are superimposed with the casting characteristics inherent for aluminum cast alloy compositions without containing Cu elements.
  • Aluminum alloys have been successfully used in a wide range of structural applications because of their relatively low density, high strength and elastic modulus, fatigue resistance and ease of fabrication. This is particularly important for the transportation industry because structural weight savings are becoming more critical as fuel consumption and air pollution concerns come to the forefront of technological issues. For example, automotive
  • the multitude of aluminum alloys can be divided into the categories of wrought and cast aluminum alloys. Wrought aluminum alloys are generally processed by the plastic
  • Cast aluminum alloys differ greatly from wrought aluminum alloys as cast aluminium alloys are ultimately used in the geometry of the original mould Therefore; many of the beneficial processing steps used to produce wrought aluminum are not practical for use in castings.
  • the alloy design goals, microstructure, processing steps and strengthening mechanisms are the major aspects for making castings with enhanced mechanical properties.
  • Al-Si systems are one of the most popular materials in casting manufacturing because of their excellent casting performance, high specific strength and toughness, and good fatigue resistance and corrosion resistance, etc.
  • a commonly used high performance aluminum casting alloy is Aluminum Association alloy 356/357 with a nominal composition of 7.0 wt.% Si and 0.3 to 0.45 wt.% Mg and minor amounts of Ti, Mn, Fe, Be, and Cu. Mechanical properties in the highest strength temper are among the highest in the aluminum cast alloy systems.
  • the existing alloys are generally capable of satisfying in many critical load-bearing structures, with the development of automotive, aviation, aerospace and military industry, the tensile strength and elongation of Al-Si alloys of a higher requirement, conventional grades of Al-Si alloys have been unable to meet the needs of a number of automotive and aerospace products. Therefore, development of high strength castings based on new Al-Si alloy is an urgent need. There are numerous efforts to develop new materials and technologies.
  • WO2010003349 discloses a high strength casting aluminium alloy material comprises (in weight %) Cu 2.0-6.0 %, Mn 0.05-1.0 %, Ti 0.01-0.5 %, Cr 0.01-0.2 %, Cd 0.01-0.4 %, Zr 0.01-0.25 %, B 0.005-0.04 %, rare earth 0.05-0.3 %, and balance aluminium and trace impurities.
  • the alloy has reduced cost.
  • EP1347066 discloses a high-strength aluminum alloy for casting comprising 3.5 to 4.3 % of Cu, 5.0 to 7.5 % of Si, 0.10 to 0.25 % of Mg, not more than 0.2 % of Fe, 0.0004 to 0.0030 % of P, 0.005 to 0.0030 % of Sr, and the balance comprising Al and unavoidable impurities.
  • a high-strength cast aluminum alloy is also disclosed obtained by: casting a high-strength aluminum alloy for casting comprising 3.5 to 4.3 % of Cu, 5.0 to 7.5 % of Si, 0.10 to 0.25 % of Mg, not more than 0.2 % of Fe, 0.0004 to 0.0030 % of P, 0.005 to 0.030 % of Sr, 0.05 to 0.35 % of Ti, and the balance comprising Al and unavoidable impurities; and subjecting the alloy thus cast to a T6 treatment.
  • WO2015121635 (Brunei University) discloses a high strength cast aluminium alloy for high pressure die casting comprising magnesium silicide 6 to 12 wt.%, magnesium 4 to 10 wt.%, X element from copper (Cu), zinc (Zn), silver (Ag), gold (Au) and Lithium (Li) at 3 to 10 wt.%), manganese 0.1 to 1.2 wt.%>, iron max.
  • EP2865772 discloses an aluminium casting alloy comprising 7-9 % by weight of silicon, 0.6- 1 % by weight of iron, 0.7-1.5 % by weight of copper, 0.05-0.5 % by weight of manganese, 0.1-3 % by weight of zinc, 0.05-0.5 % by weight of magnesium, 0.01-0.15 % by weight of titanium, 0.01-0.1 % by weight of chrome, 0.01-0.1 % by weight of nickel, 0.01-0.1 % by weight of lead and 0.01-0.1 % by weight of tin.
  • WO2004104240 discloses a high-strength, thermally-resistant, ductile, cast aluminium alloy (AlSi7Mg0.25Zr, or AlSi7Mg0.25Hf) and (Al Si6Mg0.25Zr or Al Si6Mg0.25Hf), comprising Si: 6.5 to 7.5 wt.% and 5.5 to 6.5 wt.%, Mg: 0.20 to 0.32 wt.%, Zr: 0.03 to 0.50 wt.% and/or Hf: 0.03 to 1.50 wt.%, Ti: 0 to 0.20 wt.%, Fe: ⁇ 0.20 wt.%, Mn: ⁇ 0.50 wt.%, Cu: ⁇ 0.05 wt.%), Zn: ⁇ 0.07 wt.% and made up to 100 wt.% with Al.
  • the invention relates to the use thereof for workpieces or parts thereof with elevated thermal loading, such as a cylinder head.
  • Al-Si-Mg alloys Despite the property of casting Al-Si-Mg alloys is among the highest and the relatively high amount of Si affords excellent casting characteristics that are paramount to produce complex shapes.
  • the available Al-Si alloys generally offer the ultimate tensile strength (UTS) at a level of 330 MPa, the yield strength at a level of 250 MPa, and the elongation at a level of 5 %.
  • UTS ultimate tensile strength
  • the addition of Cu is not desirable because of the detrimental of corrosion resistance. Therefore, it would be highly desirable to develop castings with yield strength more than 300 MPa and UTS more than 350 MPa with an elongation more than 9 %.
  • the end users for such an alloy are quite extensive and varied, and include electrical rotors, structural members, engine bodies, cylinder heads, gear boxes, air conditioners, business machines, industrial equipment, aerospace housings, gears pumps, bearing houses, engine blocks, nodes for connecting tubular structures, wheels, aircraft fittings, flywheel castings, machine tool parts, gear blocks, general automotive castings, marine structures, pressure tight applications, recreational equipment, connecting rods and numerous other applications.
  • the new Al-Si alloys may stimulate the use of castings in new, innovative design scenarios that were not previously achievable with conventional casting alloys.
  • a method of forming a cast aluminium alloy including the steps of: (i) providing an aluminium alloy including
  • a composition of a casting alloy may be provided with a primary alloying addition of 8.5 to 12.5 wt.% Si, 0.46 to 1.0 wt.% Mg, 0.1 to 0.2 wt.% Ti, 0.05 to 0.25 wt.% Mn, and less than 0.05 wt.%) Sn.
  • the alloy could further include grain refining additions of Ti, TiB 2 , A1B 2 , B, Be, Zr, Y, V, Nb, singly or in combination with one another in the range of 0.001 to 1.0 wt.%), chemical modifiers such as Na and Sr, singly or in combination with one another in the range of 0.001 to about 0.10 wt.%> and phase refiners such as P in the range of 0.01 to about 0.30 wt.%), and the balance of Al and incidental impurities.
  • An optimised process for melt treatment may include appropriate melting, degassing, and grain refining.
  • Al-10 wt.%> Sr master alloy is added into the melt to the preferred content of no less than 120 ppm and no higher than 200 ppm for the modification and refinement of the eutectic silicon phase.
  • the molten metal is degassed using nitrogen, argon or chlorine or their mixtures injected into the melt by means of a rotary degassing impeller at a speed of at least 150 rpm for at least 10 min.
  • the degassing process includes the introduction of at least one of nitrogen, argon or chlorine or their mixtures into the alloy melt to remove the dissolved hydrogen in the melt to a level of less than 2 mL/100 g. It is preferred that the dissolved hydrogen in the melt can be reduced to a level of less than 0.7 mL/100 g, even preferably to a level of less than 0.2 mL/100 g. Then TiB-containing master alloy is added into the melt as grain refiner.
  • the refining process consists essentially of adding up to 0.3 wt.%> grain refiners into the aluminium alloy melt, which includes the TiB-containing master alloy for refining primary aluminium phase, which is at least one of ⁇ 1-5 ⁇ 1 ⁇ , ⁇ 1-3 ⁇ 1 ⁇ , Al- 1 ⁇ 3 ⁇ , or ⁇ 1-3 ⁇ 3 ⁇ alloys.
  • the alternation method is adding 25% Na 2 SiF 6 + 75% C 2 C1 6 refining agents and with the rotary degassing unit with the use of the best refining effect in an amount of 0.5-0.8 wt.%.
  • the amount of grain refiner can be preferably at a level of up to 0.2 wt.%. After degassing, the top surface of the melt is covered by commercial granular flux, then the melt is held for 10-15 min, thereafter the melt is ready for casting, and the preferred casting temperature is at 700-720 °C.
  • An embodiment may include an optimised process for heat treatment of castings made by the developed aluminium alloys.
  • the heat treatment in accordance with the practice that involves the steps of solution heat treatment at temperatures approaching the solidus temperature of a given alloy; quenching into water or other appropriate media, and ageing at temperatures ranging from ambient to about 300°C.
  • a multiple stages solution process and multiple stages ageing process can be utilized.
  • the solution is conducted at a temperature between 520 °C to 545 °C, preferably between 530 °C to 540 °C, and more preferably between 535 °C to 540 °C.
  • the solution time at the more preferably solution temperature 540 °C is between 2 h to 12 h, preferably between 8 h to 10 h, as indicated in Fig.
  • the ageing is conducted at a temperature between 170 °C to 200 °C, preferably between 170 °C to 190 °C, and more preferably at 170 °C or 190 °C.
  • the ageing time at the more preferably ageing temperature is between 2 h to 8 h, preferably ageing at 170 °C for 7-8 h or ageing at 190 °C for 3-4 h, as indicated in Fig. 2.
  • the optimised heat treatment process for the alloy is solution at 540 °C for 8-10 h, then quenching into water or other appropriate media, after ageing at 170 °C for 7-8 h or ageing at 190 °C for 3-4 h, as indicated in Fig. 3.
  • the alloy and manufacturing method of Al-Si-Mg castings preferably provide enhanced mechanical properties for structural applications comprising (1) alloy optimisation with 8.5 to 12.5 wt.% Si, 0.46 to 1.0 wt.% Mg, 0.1 to 0.2 wt.% Ti, 0.05 to 0.25 wt.% Mn, 0.01 to 0.02 wt.%) Sr, 0.004 to 0.1 wt.%> B and other impurity elements of Cu, Fe, Zn each less than 0.15 wt.%) and the balance of Al and incidental impurities; (2) optimised melt treatment with appropriate melting, degassing and grain refining; (3) appropriate type of grain refiner with optimised amount and method to add into the aluminium melt, and (4) optimised heat treatment process.
  • the alloy and manufacturing method of Al-Si-Mg castings preferably comprises: 8.5 to 10.0 wt.% Si, 0.46 to 0.65 wt.% Mg, 0.1 to 0.15 wt.% Ti, less than 0.15 wt.% Mn, 0.012 to 0.018 wt.%) Sr, 0.004 to 0.04 wt.% B and other impurity elements of Cu, Fe, Zn each less than 0.15 wt.%) and the balance of Al and incidental impurities.
  • the alloy and manufacturing method of Al-Si-Mg castings preferably comprises less than 0.05 wt.% Cu.
  • the alloy and manufacturing method of Al-Si-Mg castings preferably comprises less than 0.12 wt.% Fe.
  • the alloy and manufacturing method of Al-Si-Mg castings preferably consists essentially of an appropriate process for making melt through degassing and grain refining.
  • the alloy and manufacturing method of Al-Si-Mg castings preferably consists essentially of degassing, in which the gas including at least one of nitrogen, argon or chlorine or their mixtures is introduced into the alloy melt to remove the dissolved hydrogen in the melt to a level of less than 2 mL/100 g melt.
  • the alloy and manufacturing method of Al-Si-Mg castings preferably consists essentially of degassing, in which the gas including at least one of nitrogen, argon or chlorine or their mixtures is introduced into the alloy melt to remove the dissolved hydrogen in the melt to a preferred level of less than 0.7 mL/100 g melt.
  • the Al- alloy and manufacturing method of Al-Si-Mg castings preferably consists essentially of degassing, in which the gas including at least one of nitrogen, argon or chlorine or their mixtures is introduced into the alloy melt to remove the dissolved hydrogen in the melt to a more preferred level of less than 0.2 mL/100 g melt.
  • the alloy and manufacturing method of Al-Si-Mg castings preferably consists essentially of cleaning the aluminium melt through pumping solid flux into aluminum melt, which can be associated with degassing process.
  • the alloy and manufacturing method of Al-Si-Mg castings preferably consists essentially of cleaning the aluminium melt through pumping chemical gas flux into aluminum melt, which can be associated with degassing process.
  • the alloy and manufacturing method of Al-Si-Mg castings preferably consists essentially of cleaning the aluminium melt through adding 25% Na 2 SiF 6 + 75% C 2 Cl 6 refining agents in an amount of 0.5-0.8 wt.% and with the rotary degassing unit.
  • the alloy and manufacturing method of Al-Si-Mg castings preferably consists essentially of adding up to 0.3 wt.% grain refiners into the aluminium alloy melt, which includes Sr- containing master alloys for modification and refining eutectic silicon phase, and TiB- containing master alloys for refining primary aluminium phase.
  • the alloy and manufacturing method of Al-Si-Mg castings preferably consists essentially of adding up to 0.2 wt.% grain refiners into the aluminium alloy melt, which includes Sr- containing master alloys for modification and refining eutectic silicon phase, and the TiB- containing master alloy for refining primary aluminium phase.
  • the alloy and manufacturing method of Al-Si-Mg castings preferably consists essentially of refining primary aluminium phase by adding TiB-containing master alloys, which is at least one of ⁇ 1-5 ⁇ 1 ⁇ , ⁇ 1-3 ⁇ 1 ⁇ , ⁇ 1-1 ⁇ 3 ⁇ , or ⁇ 1-3 ⁇ 3 ⁇ alloys.
  • the alloy and manufacturing method of Al-Si-Mg castings preferably consists essentially of refining primary aluminium phase by adding TiB-containing master alloys, which are preferred to be ⁇ 13 ⁇ 3 ⁇ , ⁇ 11 ⁇ 3 ⁇ , or other B-rich AlTiB master alloys.
  • the alloy and manufacturing method of Al-Si-Mg castings preferably consists essentially of at least one heat treatment from solution, annealing and ageing.
  • the alloy and manufacturing method of Al-Si-Mg castings preferably consists essentially of at least one solution at a temperature between 520 °C to 545 °C.
  • the alloy and manufacturing method of Al-Si-Mg castings preferably consists essentially of at least one solution at a temperature preferably between 530 °C to 540 °C.
  • the alloy and manufacturing method of Al-Si-Mg castings preferably consists essentially of at least one solution at a temperature more preferably between 535 °C to 540 °C.
  • the alloy and manufacturing method of Al-Si-Mg castings preferably consists essentially of at least one solution for a time between 2 h to 12 h.
  • the alloy and manufacturing method of Al-Si-Mg castings preferably consists essentially of at least one solution for a time preferably between 8 h to 10 h.
  • the alloy and manufacturing method of Al-Si-Mg castings preferably consists essentially of at least one ageing at a temperature between 170 °C to 200 °C.
  • the alloy and manufacturing method of Al-Si-Mg castings preferably consists essentially of at least one ageing at a temperature preferably between 170 °C to 190 °C.
  • the alloy and manufacturing method of Al-Si-Mg castings preferably consists essentially of at least one ageing at the temperature more preferably 170 °C or 190 °C.
  • the alloy and manufacturing method of Al-Si-Mg castings preferably consists essentially of at least one ageing for a time between 2 h to 8 h.
  • the alloy and manufacturing method of Al-Si-Mg castings preferably consists essentially of at least one ageing preferably at 170°C for 7 h to 8 h or 190°C for 3 h to 4h.
  • the alloy and manufacturing method of Al-Si-Mg castings to provide enhanced mechanical properties for structural applications preferably comprises (1) alloy optimisation with 8.5 to 10.0 wt.% Si, 0.46 to 0.65 wt.% Mg, 0.1 to 0.15 wt.% Ti, less than 0.15 wt.% Mn, 0.012 to 0.018 wt.% Sr, 0.004 to 0.04 wt.% B and other impurity elements of Cu, Fe, Zn each less than 0.15 wt.% and the balance of Al and incidental impurities; (2) optimised melt treatment with appropriate melting, modification, degassing and grain refining; (3) appropriate type of grain refiner with optimised amount and method to add into the aluminium melt, and (4) optimised heat treatment process.
  • Fig. 1 is a graph showing micro hardness of the alloy versus solution time at a solution temperature of 540 °C
  • Fig. 2 is a graph showing micro hardness of the alloy versus ageing time at an ageing temperature of 170 °C after solution at 540 °C for 8 hours;
  • Fig. 3 is a graph showing yield strength of the alloy versus ageing time at an ageing temperature of 170 °C after solution at 540 °C for 6-14 hours.
  • an alloy system in accordance with the principles of the present invention is a modification of the Aluminum Association's alloy system 3XX.
  • This modified alloy system generally comprises of Si in the range of 8.5 to 12.5 wt.% and Mg in the range of 0.3 to 0.7 wt.%), with one or more of Ti less than 0.2 wt.%, Mn less than 0.1 wt.%, Zn less than 0.1 wt.%, Sn less than 0.05 wt.%.
  • the alloy could further include grain refining additions of Ti, TiB2, A1B2, B, Be, Zr, Y, V, Nb, singly or in combination with one another in the range of 0.001 to 1.0 wt.%, chemical modifiers such as Na and Sr, singly or in combination with one another in the range of 0.001 to about 0.20 wt.% and phase refiners such as P in the range of 0.01 to about 0.30 wt.%, and the balance of Al and incidental impurities.
  • an alloy system in accordance with the principles of the present invention is a modification of the Aluminum Association's alloy system 3XX.
  • This modified alloy system preferably comprises of 8.5 to 10.0 wt.% Si, 0.46 to 0.65 wt.% Mg, 0.1 to 0.15 wt.% Ti, less than 0.15 wt.% Mn, Sn less than 0.05 wt.%, and Zn less than 0.1 wt.%.
  • the alloy further include grain refining additions of Ti, TiB2, A1B2, B, Be, Zr, Y, V, Nb, singly or in combination with one another in the range of 0.001 to 0.5 wt.%, most preferably grain refining additions of 0.1 to 0.5 wt.% ⁇ 13 ⁇ 3 ⁇ master alloy comprising TiB2 and A1B2, chemical modifiers such as Na and Sr, singly or in combination with one another in the range of 0.001 to about 0.10 wt.% and phase refiners such as P in the range of 0.01 to about 0.20 wt.%), and the balance of Al and incidental impurities.
  • chemical modifiers such as Na and Sr
  • phase refiners such as P in the range of 0.01 to about 0.20 wt.%
  • the silicon can be used to improve the performance of the alloy casting, improve mobility and reduce hot cracking tendency, reduce shrinkage, improve air tightness.
  • Magnesium's role is to improve its strength and toughness; cast, in addition to a small amount of magnesium dissolved in the a-Al substrate body, mainly exists in the larger size of the Mg2Si phase, therefore, cast magnesium alloy on the mechanical properties of the obvious.
  • the role of magnesium in the alloy is achieved by heat treatment; solution treatment, magnesium dissolved a matrix of precipitated Mg2Si during aging, the alloy strengthening.
  • the castings will be cast using the conventional method of pouring the molten alloy mixture into a permanent, sand or investment type mold or alternatively cast using advanced techniques such as high pressure die casting or squeeze casting to produce a near net shape cast parts.
  • Prior to casting it is essential to have a proper degassing and grain refining.
  • the casting Al-Si alloys of the present invention may be resistance furnace smelting, alloying elements above the middle of its way and aluminium alloy added to the molten aluminium; with 25% Na 2 SiF 6 + 75% C 2 Cl 6 refining agents and with the rotary degassing unit with the use of the best refining effect in amount of 0.5-0.8 % (mass percentage).
  • the casting is subjected to an appropriate heat treatment in accordance with the practice that involves the steps of solution heat treatment at temperatures approaching the solidus temperature of a given alloy; quenching into water or other appropriate media, and ageing at temperatures ranging from ambient to about 300 °C.
  • an appropriate heat treatment in accordance with the practice that involves the steps of solution heat treatment at temperatures approaching the solidus temperature of a given alloy; quenching into water or other appropriate media, and ageing at temperatures ranging from ambient to about 300 °C.
  • a multiple stages solution process and multiple stages ageing process can be utilized.
  • it includes primary ageing at a low temperature (e.g., less than about 190 °C, preferably less than 160 °C) for an short period of time (e.g.
  • alloys which embody the present invention, have been shown to have yield strengths (0.2% offset) in excess of 300 MPa and elongation in excess of 10 %.
  • the alloys listed in Table 1 Four alloys of the compositions listed in Table 1 were cast into a permanent mold.
  • the alloys also include an A356 and an A357 type cast aluminum alloys.
  • the castings were made by weighting different elements with an appropriate ratio and melting them in a 12 kg clay- graphite crucible in an electric resistance furnace. When the melt was fully homogenised, it was subjected to degassing, during which Ar was blown into the melt by a commercial rotatory degasser adjusted at 350 rpm for 4 min. It should be mentioned that Al-lOSr alloy was added at 0.01-0.02 wt.% Sr before degassing. TiB-containing refiner was added at 720 °C with 0.005 wt.% of B and before pouring.
  • melt was poured into the boron nitride painted steel mould, designed based on ASTM B108 standard, to produce dog- bone shape tensile specimens.
  • molten metal was poured into the steel mold which was already heated up to 400-460 °C.
  • composition analysis was carried out using the Foundry-Master Pro which is a high- performing optical emission spectrometer (OES). Each of the four castings was solution heat treated at 540 °C for 8 hours, immediately quenched into ambient temperature water upon removal from the furnace and allowed to stabilize for several days. Ageing was optimized for each alloy by taking Vickers hardness measurements in accordance with the American Society for Testing and Materials (ASTM) standard E92-82 at selected time intervals for a wide range of temperatures. The optimized ageing process is ageing at 170 °C for 8 hours or ageing at 190°C for 4 hours. The mechanical properties were further measured in accordance with ASTM B557 standard using an Instron 5500 Universal Electromechanical Testing Systems equipped with Bluehill software and a ⁇ 50 kN load cell.
  • ASTM B557 Standard using an Instron 5500 Universal Electromechanical Testing Systems equipped with Bluehill software and a ⁇ 50 kN load cell.
  • the developed alloys labelled as GCOl and GC02 display higher strengths and elongations over the commercially available A356 and A357 alloys. This is especially surprising given that the A357 alloy is by far the highest strength alloy in the Al- Si-Mg cast alloy system. Moreover, the Mg content is higher in the A357 alloy, in which Mg content is 0.5-0.7 wt.%. Since published yield strength values (source: Metals Handbook Desk Edition. American Society for metals, H.E. Boyer and T.L. Gall, eds., 1985, pp.
  • the alloys listed in Table 3 Four alloys of the compositions listed in Table 3 were cast into a sand mold.
  • the alloys also include an A356 and an A357 type cast aluminum alloys.
  • the castings were made by weighting different elements with an appropriate ratio and melting them in a 12 kg clay- graphite crucible in an electric resistance furnace. When the melt was fully homogenised, it was subjected to degassing, during which Ar was blown into the melt by a commercial rotatory degasser adjusted at 350 rpm for 4 min. It should be mentioned that Al-lOSr alloy was added at 0.01-0.02 wt.% Sr before degassing. TiB-containing refiner was added at 720 °C with 0.005 wt.% of B and before pouring.
  • melt was poured into the British standard sand mould, to produce dog-bone shape tensile specimens.
  • molten metal was poured into the sand mold which was at room temperature.
  • Chemical composition analysis was carried out using the Foundry-Master Pro which is a high-performing optical emission spectrometer (OES).
  • Each of the four castings was solution heat treated at 540 °C for 8 hours, immediately quenched into ambient temperature water upon removal from the furnace and allowed to stabilize for several days.
  • Ageing was optimized for each alloy by taking Vickers hardness measurements in accordance with the American Society for Testing and Materials (ASTM) standard E92-82 at selected time intervals for a wide range of temperatures. The optimized ageing process is at 170 °C for 8 hours or at 190°C for 4 hours.
  • the mechanical properties were further measured in accordance with ASTM B557 standard using an Instron 5500 Universal Electromechanical Testing Systems equipped with Bluehill software and a ⁇ 50 kN load cell. All the tensile tests were performed at ambient temperature ( ⁇ 25 °C). The gauge length of the extensometer was 50 mm and the ramp rate for extension was 1 mm/min.
  • the mechanical properties of the four castings after solution and ageing treatment are listed in Table 4. TABLE 3
  • the commercially available A356 alloy displays a yield strength of 230 MPa and an UTS of 280 MPa with 0.35 wt.% Mg
  • the commercially available A357 alloy shows a yield strength of 275 MPa and an UTS of 300 MPa with 0.5 wt.% Mg
  • the developed alloys labelled SCOl and SC02 with 0.5 wt.% Mg display a remarkable increase of strength over the commercially available A356 and A357 alloys, with a yield strength above 295 MPa and an UTS above 325MPa. This is especially surprising given that the A357 alloy is by far the highest strength alloy in the Al-Si-Mg cast alloy system.
  • the Mg content is higher in the A357 alloy, in which Mg content is 0.5-0.7 wt.%, and the A357 alloy achieves higher strength over the A356 alloy at higher Mg content with significant decrease of elongation to be below 3 %, while the developed alloys achieve higher strength over the A356 alloy without obvious decrease of elongation.
  • the developed compositions are very potent in overcoming this large property disparity that is observed with slightly different Mg levels. If the Mg content were adjusted to the 0.60 weight percent level or above, it is likely that the strength of the developed alloys would be even greater.

Landscapes

  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Materials Engineering (AREA)
  • Metallurgy (AREA)
  • Organic Chemistry (AREA)
  • Physics & Mathematics (AREA)
  • Thermal Sciences (AREA)
  • Crystallography & Structural Chemistry (AREA)
  • Continuous Casting (AREA)

Abstract

La présente invention concerne des pièces coulées d'Al-Si-Mg permettant d'obtenir des propriétés mécaniques améliorées pour des applications structurales comprenant (1) une optimisation d'alliage contenant de 8,5 à 12,5 % en poids de Si, de 0,46 à 1,0 % en poids de Mg, de 0,1 à 0,2 % en poids de Ti, de 0,05 à 0,25 % en poids de Mn, de 0,01 à 0,02 % en poids de Sr, de 0,004 à 0,1 % en poids de B et d'autres éléments d'impuretés de Cu, de Fe, de Zn, chacun inférieur à 0,15 % en poids, et le reste d'Al ; (2) un traitement à l'état fondu optimisé comprenant une fusion, une modification, un dégazage et un raffinage de grain appropriés ; (3) un type approprié de raffineur de grains à quantité optimisée et un procédé d'ajout dans le bain d'aluminium, et (4) un processus de traitement thermique optimisé. Lorsqu'elles sont utilisées pour fabriquer des pièces coulées en alliage d'aluminium profilé par mise en œuvre d'un procédé de coulée par gravité, les pièces coulées présentent une limite d'élasticité conventionnelle à 0,2 % supérieure à 310 MPa, une résistance à la traction supérieure à 365 MPa et un allongement supérieur à 10 %.The present invention relates to Al-Si-Mg castings for improved mechanical properties for structural applications comprising (1) alloy optimization containing from 8.5 to 12.5 wt% Si, from 0.46 to 1.0% by weight of Mg, from 0.1 to 0.2% by weight of Ti, from 0.05 to 0.25% by weight of Mn, from 0.01 to 0.02 % by weight of Sr, from 0.004 to 0.1% by weight of B and other impurity elements of Cu, Fe, Zn, each less than 0.15% by weight, and the remainder of Al ; (2) optimized melt processing including proper melting, modification, degassing and grain refining; (3) a suitable type of optimized quantity grain refiner and method of adding to the aluminum bath, and (4) an optimized heat treatment process. When used to fabricate cast aluminum alloy castings by a gravity casting process, castings have a 0.2% conventional yield strength greater than 310 MPa tensile strength greater than 365 MPa and elongation greater than 10%.

Description

Method of forming a cast aluminium alloy
FIELD OF THE INVENTION
The present invention generally relates to a method of forming a cast aluminium alloy, and in particular aluminum castings for enhanced mechanical properties in structural applications. When utilized to make shape aluminium alloy castings with gravity casting process, the castings have achieved a 0.2 % offset yield strength of greater than 310 MPa, an ultimate tensile strength of greater than 365 MPa, and an elongation of greater than 10 %. More specifically, the excellent strength and ductility properties are superimposed with the casting characteristics inherent for aluminum cast alloy compositions without containing Cu elements.
BACKGROUND OF THE INVENTION
Aluminum alloys have been successfully used in a wide range of structural applications because of their relatively low density, high strength and elastic modulus, fatigue resistance and ease of fabrication. This is particularly important for the transportation industry because structural weight savings are becoming more critical as fuel consumption and air pollution concerns come to the forefront of technological issues. For example, automotive
manufacturers are currently using aluminum in unprecedented tonnages. This upward trend of aluminum usage is expected to continue for several years.
The multitude of aluminum alloys can be divided into the categories of wrought and cast aluminum alloys. Wrought aluminum alloys are generally processed by the plastic
deformation or cold working of the initial cast billet into final desired shapes through rolling, extruding, forging and/or drawing. Cast aluminum alloys differ greatly from wrought aluminum alloys as cast aluminium alloys are ultimately used in the geometry of the original mould Therefore; many of the beneficial processing steps used to produce wrought aluminum are not practical for use in castings. The alloy design goals, microstructure, processing steps and strengthening mechanisms are the major aspects for making castings with enhanced mechanical properties. In cast aluminum alloys, Al-Si systems are one of the most popular materials in casting manufacturing because of their excellent casting performance, high specific strength and toughness, and good fatigue resistance and corrosion resistance, etc. A commonly used high performance aluminum casting alloy is Aluminum Association alloy 356/357 with a nominal composition of 7.0 wt.% Si and 0.3 to 0.45 wt.% Mg and minor amounts of Ti, Mn, Fe, Be, and Cu. Mechanical properties in the highest strength temper are among the highest in the aluminum cast alloy systems. However, although the existing alloys are generally capable of satisfying in many critical load-bearing structures, with the development of automotive, aviation, aerospace and military industry, the tensile strength and elongation of Al-Si alloys of a higher requirement, conventional grades of Al-Si alloys have been unable to meet the needs of a number of automotive and aerospace products. Therefore, development of high strength castings based on new Al-Si alloy is an urgent need. There are numerous efforts to develop new materials and technologies.
WO2010003349 discloses a high strength casting aluminium alloy material comprises (in weight %) Cu 2.0-6.0 %, Mn 0.05-1.0 %, Ti 0.01-0.5 %, Cr 0.01-0.2 %, Cd 0.01-0.4 %, Zr 0.01-0.25 %, B 0.005-0.04 %, rare earth 0.05-0.3 %, and balance aluminium and trace impurities. The alloy has reduced cost.
EP1347066 discloses a high-strength aluminum alloy for casting comprising 3.5 to 4.3 % of Cu, 5.0 to 7.5 % of Si, 0.10 to 0.25 % of Mg, not more than 0.2 % of Fe, 0.0004 to 0.0030 % of P, 0.005 to 0.0030 % of Sr, and the balance comprising Al and unavoidable impurities. A high-strength cast aluminum alloy is also disclosed obtained by: casting a high-strength aluminum alloy for casting comprising 3.5 to 4.3 % of Cu, 5.0 to 7.5 % of Si, 0.10 to 0.25 % of Mg, not more than 0.2 % of Fe, 0.0004 to 0.0030 % of P, 0.005 to 0.030 % of Sr, 0.05 to 0.35 % of Ti, and the balance comprising Al and unavoidable impurities; and subjecting the alloy thus cast to a T6 treatment.
WO2015121635 (Brunei University) discloses a high strength cast aluminium alloy for high pressure die casting comprising magnesium silicide 6 to 12 wt.%, magnesium 4 to 10 wt.%, X element from copper (Cu), zinc (Zn), silver (Ag), gold (Au) and Lithium (Li) at 3 to 10 wt.%), manganese 0.1 to 1.2 wt.%>, iron max. 1.5 wt.%>, titanium or the other grain refining elements from Cr, Nb, and Sc with 0.02 to 0.4 wt.%, and impurity and minor alloying elements at a level of maximum 0.3 wt.% and totally < 0.5 % of at least one element selected from scandium (Sc), zirconium (Zr), Nickel (Ni), chromium (Cr), niobium (Nb), gadolinium (Gd), calcium (Ca), yttrium (Y), antinomy (Sb), bismuth (Bi), neodymium (Nd), ytterbium (Yb), vanadium (V), chromium (Cr), beryllium (Be) and boron (B) and the remainder aluminium.
EP2865772 discloses an aluminium casting alloy comprising 7-9 % by weight of silicon, 0.6- 1 % by weight of iron, 0.7-1.5 % by weight of copper, 0.05-0.5 % by weight of manganese, 0.1-3 % by weight of zinc, 0.05-0.5 % by weight of magnesium, 0.01-0.15 % by weight of titanium, 0.01-0.1 % by weight of chrome, 0.01-0.1 % by weight of nickel, 0.01-0.1 % by weight of lead and 0.01-0.1 % by weight of tin.
WO2004104240 discloses a high-strength, thermally-resistant, ductile, cast aluminium alloy (AlSi7Mg0.25Zr, or AlSi7Mg0.25Hf) and (Al Si6Mg0.25Zr or Al Si6Mg0.25Hf), comprising Si: 6.5 to 7.5 wt.% and 5.5 to 6.5 wt.%, Mg: 0.20 to 0.32 wt.%, Zr: 0.03 to 0.50 wt.% and/or Hf: 0.03 to 1.50 wt.%, Ti: 0 to 0.20 wt.%, Fe: < 0.20 wt.%, Mn: < 0.50 wt.%, Cu: < 0.05 wt.%), Zn: < 0.07 wt.% and made up to 100 wt.% with Al. The invention relates to the use thereof for workpieces or parts thereof with elevated thermal loading, such as a cylinder head.
Despite the property of casting Al-Si-Mg alloys is among the highest and the relatively high amount of Si affords excellent casting characteristics that are paramount to produce complex shapes. However, the available Al-Si alloys generally offer the ultimate tensile strength (UTS) at a level of 330 MPa, the yield strength at a level of 250 MPa, and the elongation at a level of 5 %. The addition of Cu is not desirable because of the detrimental of corrosion resistance. Therefore, it would be highly desirable to develop castings with yield strength more than 300 MPa and UTS more than 350 MPa with an elongation more than 9 %. This will not only decrease the cost of producing components by casting alloys, but also be clear advantageous if a new, innovative cast Al-Si alloy composition could be used with properties that are far superior to those developed thus far. More importantly, the excellent strength and ductility properties are preferably superimposed with the casting characteristics inherent for aluminum cast alloy compositions without containing Cu elements. The general principle of the present invention is the disclosure of new types of casting alloys that contain all of the advantageous properties required of castings: e.g., excellent fluidity and castability, combined with the favorable mechanical properties. The end users for such an alloy are quite extensive and varied, and include electrical rotors, structural members, engine bodies, cylinder heads, gear boxes, air conditioners, business machines, industrial equipment, aerospace housings, gears pumps, bearing houses, engine blocks, nodes for connecting tubular structures, wheels, aircraft fittings, flywheel castings, machine tool parts, gear blocks, general automotive castings, marine structures, pressure tight applications, recreational equipment, connecting rods and numerous other applications. Along with the aforementioned applications that have already been established with conventional castings, the new Al-Si alloys may stimulate the use of castings in new, innovative design scenarios that were not previously achievable with conventional casting alloys.
In accordance with a first aspect of the invention, there is provided a method of forming a cast aluminium alloy, including the steps of: (i) providing an aluminium alloy including
from 8.5 to 12.5 wt.% Si,
from 0.4 to 1.0 wt.% Mg,
up to 0.2 wt.% Ti,
from 0.05 to 0.25 wt.% Mn,
from 0.002 to 0.04 wt.% Sr,
from 0.001 to 0.1 wt.% B
and other impurity elements of Cu, Fe, Zn, each at less than 0.15 wt.% with the balance being Al;
(ii) melting said alloy; (iii) degassing the alloy melt by introducing into the melt a gas including at least one of nitrogen, argon or chlorine or a mixture thereof in order to reduce dissolved hydrogen in the melt to a level of less than 0.7 mL/100 g melt;
(iv) cleaning the alloy melt by adding 25% Na2SiF6 and 75% C2C16 refining agents in an amount from 0.01-0.8 wt.%; (v) adding a grain refiner in the form of a TiB-containing master alloy, a B-containing master alloy, or an Al-B master alloys with the boron content up to 0.1 wt.% B;
(vi) refining and modifying the eutectic silicon phase by adding from 0.002 to 0.04 wt.% Sr in the form of an Al-Sr master alloys; (vii) carrying out a solution heat treatment at a temperature from 520 °C to 545 °C for a time from 2 h to 12 h; and
(viii) carrying out an ageing heat treatment at a temperature from 170 °C to 200 °C for a time from 2 h to 8 h.
A composition of a casting alloy may be provided with a primary alloying addition of 8.5 to 12.5 wt.% Si, 0.46 to 1.0 wt.% Mg, 0.1 to 0.2 wt.% Ti, 0.05 to 0.25 wt.% Mn, and less than 0.05 wt.%) Sn. In addition, the alloy could further include grain refining additions of Ti, TiB2, A1B2, B, Be, Zr, Y, V, Nb, singly or in combination with one another in the range of 0.001 to 1.0 wt.%), chemical modifiers such as Na and Sr, singly or in combination with one another in the range of 0.001 to about 0.10 wt.%> and phase refiners such as P in the range of 0.01 to about 0.30 wt.%), and the balance of Al and incidental impurities.
An optimised process for melt treatment may include appropriate melting, degassing, and grain refining. After at least one hour of homogenisation of the melt, Al-10 wt.%> Sr master alloy is added into the melt to the preferred content of no less than 120 ppm and no higher than 200 ppm for the modification and refinement of the eutectic silicon phase. At least 15 minutes after the adding the Sr, the molten metal is degassed using nitrogen, argon or chlorine or their mixtures injected into the melt by means of a rotary degassing impeller at a speed of at least 150 rpm for at least 10 min. The degassing process includes the introduction of at least one of nitrogen, argon or chlorine or their mixtures into the alloy melt to remove the dissolved hydrogen in the melt to a level of less than 2 mL/100 g. It is preferred that the dissolved hydrogen in the melt can be reduced to a level of less than 0.7 mL/100 g, even preferably to a level of less than 0.2 mL/100 g. Then TiB-containing master alloy is added into the melt as grain refiner. The refining process consists essentially of adding up to 0.3 wt.%> grain refiners into the aluminium alloy melt, which includes the TiB-containing master alloy for refining primary aluminium phase, which is at least one of Α1-5ΤΪ1Β, Α1-3ΤΪ1Β, Al- 1ΤΪ3Β, or Α1-3ΤΪ3Β alloys. The alternation method is adding 25% Na2SiF6 + 75% C2C16 refining agents and with the rotary degassing unit with the use of the best refining effect in an amount of 0.5-0.8 wt.%. The amount of grain refiner can be preferably at a level of up to 0.2 wt.%. After degassing, the top surface of the melt is covered by commercial granular flux, then the melt is held for 10-15 min, thereafter the melt is ready for casting, and the preferred casting temperature is at 700-720 °C.
An embodiment may include an optimised process for heat treatment of castings made by the developed aluminium alloys. The heat treatment in accordance with the practice that involves the steps of solution heat treatment at temperatures approaching the solidus temperature of a given alloy; quenching into water or other appropriate media, and ageing at temperatures ranging from ambient to about 300°C. Alternatively, a multiple stages solution process and multiple stages ageing process can be utilized. The solution is conducted at a temperature between 520 °C to 545 °C, preferably between 530 °C to 540 °C, and more preferably between 535 °C to 540 °C. The solution time at the more preferably solution temperature 540 °C is between 2 h to 12 h, preferably between 8 h to 10 h, as indicated in Fig. 1. The ageing is conducted at a temperature between 170 °C to 200 °C, preferably between 170 °C to 190 °C, and more preferably at 170 °C or 190 °C. The ageing time at the more preferably ageing temperature is between 2 h to 8 h, preferably ageing at 170 °C for 7-8 h or ageing at 190 °C for 3-4 h, as indicated in Fig. 2. The optimised heat treatment process for the alloy is solution at 540 °C for 8-10 h, then quenching into water or other appropriate media, after ageing at 170 °C for 7-8 h or ageing at 190 °C for 3-4 h, as indicated in Fig. 3.
The alloy and manufacturing method of Al-Si-Mg castings preferably provide enhanced mechanical properties for structural applications comprising (1) alloy optimisation with 8.5 to 12.5 wt.% Si, 0.46 to 1.0 wt.% Mg, 0.1 to 0.2 wt.% Ti, 0.05 to 0.25 wt.% Mn, 0.01 to 0.02 wt.%) Sr, 0.004 to 0.1 wt.%> B and other impurity elements of Cu, Fe, Zn each less than 0.15 wt.%) and the balance of Al and incidental impurities; (2) optimised melt treatment with appropriate melting, degassing and grain refining; (3) appropriate type of grain refiner with optimised amount and method to add into the aluminium melt, and (4) optimised heat treatment process. The alloy and manufacturing method of Al-Si-Mg castings preferably comprises: 8.5 to 10.0 wt.% Si, 0.46 to 0.65 wt.% Mg, 0.1 to 0.15 wt.% Ti, less than 0.15 wt.% Mn, 0.012 to 0.018 wt.%) Sr, 0.004 to 0.04 wt.% B and other impurity elements of Cu, Fe, Zn each less than 0.15 wt.%) and the balance of Al and incidental impurities.
The alloy and manufacturing method of Al-Si-Mg castings preferably comprises less than 0.05 wt.% Cu.
The alloy and manufacturing method of Al-Si-Mg castings, preferably comprises less than 0.12 wt.% Fe.
The alloy and manufacturing method of Al-Si-Mg castings preferably consists essentially of an appropriate process for making melt through degassing and grain refining. The alloy and manufacturing method of Al-Si-Mg castings preferably consists essentially of degassing, in which the gas including at least one of nitrogen, argon or chlorine or their mixtures is introduced into the alloy melt to remove the dissolved hydrogen in the melt to a level of less than 2 mL/100 g melt. The alloy and manufacturing method of Al-Si-Mg castings preferably consists essentially of degassing, in which the gas including at least one of nitrogen, argon or chlorine or their mixtures is introduced into the alloy melt to remove the dissolved hydrogen in the melt to a preferred level of less than 0.7 mL/100 g melt. The Al- alloy and manufacturing method of Al-Si-Mg castings preferably consists essentially of degassing, in which the gas including at least one of nitrogen, argon or chlorine or their mixtures is introduced into the alloy melt to remove the dissolved hydrogen in the melt to a more preferred level of less than 0.2 mL/100 g melt.
The alloy and manufacturing method of Al-Si-Mg castings preferably consists essentially of cleaning the aluminium melt through pumping solid flux into aluminum melt, which can be associated with degassing process. The alloy and manufacturing method of Al-Si-Mg castings preferably consists essentially of cleaning the aluminium melt through pumping chemical gas flux into aluminum melt, which can be associated with degassing process.
The alloy and manufacturing method of Al-Si-Mg castings preferably consists essentially of cleaning the aluminium melt through adding 25% Na2SiF6 + 75% C2Cl6 refining agents in an amount of 0.5-0.8 wt.% and with the rotary degassing unit. The alloy and manufacturing method of Al-Si-Mg castings preferably consists essentially of adding up to 0.3 wt.% grain refiners into the aluminium alloy melt, which includes Sr- containing master alloys for modification and refining eutectic silicon phase, and TiB- containing master alloys for refining primary aluminium phase. The alloy and manufacturing method of Al-Si-Mg castings preferably consists essentially of adding up to 0.2 wt.% grain refiners into the aluminium alloy melt, which includes Sr- containing master alloys for modification and refining eutectic silicon phase, and the TiB- containing master alloy for refining primary aluminium phase. The alloy and manufacturing method of Al-Si-Mg castings preferably consists essentially of refining primary aluminium phase by adding TiB-containing master alloys, which is at least one of Α1-5ΤΪ1Β, Α1-3ΤΪ1Β, Α1-1ΤΪ3Β, or Α1-3ΤΪ3Β alloys.
The alloy and manufacturing method of Al-Si-Mg castings preferably consists essentially of refining primary aluminium phase by adding TiB-containing master alloys, which are preferred to be Α13ΤΪ3Β, Α11ΤΪ3Β, or other B-rich AlTiB master alloys.
The alloy and manufacturing method of Al-Si-Mg castings preferably consists essentially of at least one heat treatment from solution, annealing and ageing.
The alloy and manufacturing method of Al-Si-Mg castings preferably consists essentially of at least one solution at a temperature between 520 °C to 545 °C. The alloy and manufacturing method of Al-Si-Mg castings preferably consists essentially of at least one solution at a temperature preferably between 530 °C to 540 °C. The alloy and manufacturing method of Al-Si-Mg castings preferably consists essentially of at least one solution at a temperature more preferably between 535 °C to 540 °C.
The alloy and manufacturing method of Al-Si-Mg castings preferably consists essentially of at least one solution for a time between 2 h to 12 h.
The alloy and manufacturing method of Al-Si-Mg castings preferably consists essentially of at least one solution for a time preferably between 8 h to 10 h.
The alloy and manufacturing method of Al-Si-Mg castings preferably consists essentially of at least one ageing at a temperature between 170 °C to 200 °C.
The alloy and manufacturing method of Al-Si-Mg castings preferably consists essentially of at least one ageing at a temperature preferably between 170 °C to 190 °C. The alloy and manufacturing method of Al-Si-Mg castings preferably consists essentially of at least one ageing at the temperature more preferably 170 °C or 190 °C.
The alloy and manufacturing method of Al-Si-Mg castings preferably consists essentially of at least one ageing for a time between 2 h to 8 h.
The alloy and manufacturing method of Al-Si-Mg castings preferably consists essentially of at least one ageing preferably at 170°C for 7 h to 8 h or 190°C for 3 h to 4h.
The alloy and manufacturing method of Al-Si-Mg castings to provide enhanced mechanical properties for structural applications preferably comprises (1) alloy optimisation with 8.5 to 10.0 wt.% Si, 0.46 to 0.65 wt.% Mg, 0.1 to 0.15 wt.% Ti, less than 0.15 wt.% Mn, 0.012 to 0.018 wt.% Sr, 0.004 to 0.04 wt.% B and other impurity elements of Cu, Fe, Zn each less than 0.15 wt.% and the balance of Al and incidental impurities; (2) optimised melt treatment with appropriate melting, modification, degassing and grain refining; (3) appropriate type of grain refiner with optimised amount and method to add into the aluminium melt, and (4) optimised heat treatment process. All the above and other characteristics and advantages of the invention will be further understood through the following illustrative and non-limitative description of embodiments thereof, with reference to the appended examples and drawings, in which:
Fig. 1 is a graph showing micro hardness of the alloy versus solution time at a solution temperature of 540 °C; Fig. 2 is a graph showing micro hardness of the alloy versus ageing time at an ageing temperature of 170 °C after solution at 540 °C for 8 hours; and
Fig. 3 is a graph showing yield strength of the alloy versus ageing time at an ageing temperature of 170 °C after solution at 540 °C for 6-14 hours.
In one embodiment, an alloy system in accordance with the principles of the present invention is a modification of the Aluminum Association's alloy system 3XX. This modified alloy system generally comprises of Si in the range of 8.5 to 12.5 wt.% and Mg in the range of 0.3 to 0.7 wt.%), with one or more of Ti less than 0.2 wt.%, Mn less than 0.1 wt.%, Zn less than 0.1 wt.%, Sn less than 0.05 wt.%. In addition, the alloy could further include grain refining additions of Ti, TiB2, A1B2, B, Be, Zr, Y, V, Nb, singly or in combination with one another in the range of 0.001 to 1.0 wt.%, chemical modifiers such as Na and Sr, singly or in combination with one another in the range of 0.001 to about 0.20 wt.% and phase refiners such as P in the range of 0.01 to about 0.30 wt.%, and the balance of Al and incidental impurities.
In another embodiment, an alloy system in accordance with the principles of the present invention is a modification of the Aluminum Association's alloy system 3XX. This modified alloy system preferably comprises of 8.5 to 10.0 wt.% Si, 0.46 to 0.65 wt.% Mg, 0.1 to 0.15 wt.% Ti, less than 0.15 wt.% Mn, Sn less than 0.05 wt.%, and Zn less than 0.1 wt.%. In addition, the alloy further include grain refining additions of Ti, TiB2, A1B2, B, Be, Zr, Y, V, Nb, singly or in combination with one another in the range of 0.001 to 0.5 wt.%, most preferably grain refining additions of 0.1 to 0.5 wt.% Α13ΤΪ3Β master alloy comprising TiB2 and A1B2, chemical modifiers such as Na and Sr, singly or in combination with one another in the range of 0.001 to about 0.10 wt.% and phase refiners such as P in the range of 0.01 to about 0.20 wt.%), and the balance of Al and incidental impurities. In the present invention, the silicon can be used to improve the performance of the alloy casting, improve mobility and reduce hot cracking tendency, reduce shrinkage, improve air tightness. Magnesium's role is to improve its strength and toughness; cast, in addition to a small amount of magnesium dissolved in the a-Al substrate body, mainly exists in the larger size of the Mg2Si phase, therefore, cast magnesium alloy on the mechanical properties of the obvious. The role of magnesium in the alloy is achieved by heat treatment; solution treatment, magnesium dissolved a matrix of precipitated Mg2Si during aging, the alloy strengthening.
Still in another embodiment, the castings will be cast using the conventional method of pouring the molten alloy mixture into a permanent, sand or investment type mold or alternatively cast using advanced techniques such as high pressure die casting or squeeze casting to produce a near net shape cast parts. Prior to casting, it is essential to have a proper degassing and grain refining. The casting Al-Si alloys of the present invention may be resistance furnace smelting, alloying elements above the middle of its way and aluminium alloy added to the molten aluminium; with 25% Na2SiF6 + 75% C2Cl6 refining agents and with the rotary degassing unit with the use of the best refining effect in amount of 0.5-0.8 % (mass percentage). TiB-containing refiner on Al-Si alloy with good refinement effect, the best technology for the 720 °C adding 0.2-0.3 wt.% of refiner, insulation 8 min-15 min; Al- lOSr alloy has good metamorphism, added at 0. 01-0.02 wt.% Sr, was added at the temperature 740 °C; heat treatment specification: 540 °C solid solution for 8-10 hours, 170 °C aging 7-8 hours; alloy having high strength and toughness, yield strength in exceed of 300 MPa and elongation in exceed of 9 %.
Still in another embodiment, the casting is subjected to an appropriate heat treatment in accordance with the practice that involves the steps of solution heat treatment at temperatures approaching the solidus temperature of a given alloy; quenching into water or other appropriate media, and ageing at temperatures ranging from ambient to about 300 °C. Alternatively, a multiple stages solution process and multiple stages ageing process can be utilized. For example, in a two-step process, it includes primary ageing at a low temperature (e.g., less than about 190 °C, preferably less than 160 °C) for an short period of time (e.g. , longer than 1 hours but less than 10 hours, preferably about 2 hours) followed by secondary ageing at a high temperature (e.g., greater than about 100 °C, preferably about 170 °C) for an extended period of time (e.g. , longer than 2 hours but less than 48 hours, preferably about 8 hours).
Additional processing steps such as hot isostatic pressing, machining, surface modification and shot peening can be applied to further improve the casting alloys disclosed in the present invention. By utilizing the alloys of the present invention to form near net shape cast parts, significantly improved cast alloy properties can be achieved. For example, alloys, which embody the present invention, have been shown to have yield strengths (0.2% offset) in excess of 300 MPa and elongation in excess of 10 %.
The present invention will be further described with reference to Examples: EXAMPLE 1 : Gravity casting
Four alloys of the compositions listed in Table 1 were cast into a permanent mold. The alloys also include an A356 and an A357 type cast aluminum alloys. The castings were made by weighting different elements with an appropriate ratio and melting them in a 12 kg clay- graphite crucible in an electric resistance furnace. When the melt was fully homogenised, it was subjected to degassing, during which Ar was blown into the melt by a commercial rotatory degasser adjusted at 350 rpm for 4 min. It should be mentioned that Al-lOSr alloy was added at 0.01-0.02 wt.% Sr before degassing. TiB-containing refiner was added at 720 °C with 0.005 wt.% of B and before pouring. Thereafter, the melt was poured into the boron nitride painted steel mould, designed based on ASTM B108 standard, to produce dog- bone shape tensile specimens. In a gravity casting using permanent mold, molten metal was poured into the steel mold which was already heated up to 400-460 °C. Chemical
composition analysis was carried out using the Foundry-Master Pro which is a high- performing optical emission spectrometer (OES). Each of the four castings was solution heat treated at 540 °C for 8 hours, immediately quenched into ambient temperature water upon removal from the furnace and allowed to stabilize for several days. Ageing was optimized for each alloy by taking Vickers hardness measurements in accordance with the American Society for Testing and Materials (ASTM) standard E92-82 at selected time intervals for a wide range of temperatures. The optimized ageing process is ageing at 170 °C for 8 hours or ageing at 190°C for 4 hours. The mechanical properties were further measured in accordance with ASTM B557 standard using an Instron 5500 Universal Electromechanical Testing Systems equipped with Bluehill software and a ±50 kN load cell. All the tensile tests were performed at ambient temperature (~ 25 °C). The gauge length of the extensometer was 50 mm and the ramp rate for extension was 1 mm/min. The mechanical properties of the four castings after solution and ageing treatment are listed in Table 2.
TABLE 1
Table 1 Chemical composition (wt.%) of the alloys in EXAMPLE1.
Alloy Si Mg Cu Fe Mn V Ti Sr B Al
A356 6.99 0.35 0.00 0.11 0.06 0.016 0.14 0.015 0.002 Balance
A357 7.01 0.50 0.00 0.11 0.06 0.017 0.14 0.015 0.002 Balance
GCOl 9.21 0.50 0.00 0.11 0.06 0.017 0.14 0.015 0.005 Balance
GC02 9.72 0.50 0.00 0.11 0.07 0.018 0.14 0.015 0.005 Balance As shown in Table 2, the developed alloys labelled as GCOl and GC02 display higher strengths and elongations over the commercially available A356 and A357 alloys. This is especially surprising given that the A357 alloy is by far the highest strength alloy in the Al- Si-Mg cast alloy system. Moreover, the Mg content is higher in the A357 alloy, in which Mg content is 0.5-0.7 wt.%. Since published yield strength values (source: Metals Handbook Desk Edition. American Society for metals, H.E. Boyer and T.L. Gall, eds., 1985, pp. 6.48 - 6.62) for 357-T6 (0.55% Mg, yield strength 295 MPa) are about 18 % greater than those obtained with alloy 356-T6 (same composition as the 357 with 0.35% Mg, yield strength 250 MPa). Clearly, the developed compositions are very potent in overcoming this large property disparity that is observed with slightly different Mg levels. If the Mg content were adjusted to the 0.60 weight percent level or above, it is likely that the strength of the developed alloys would be even greater. More importantly, the developed alloys show good ductility with an elongation higher than 10 %. The good ductility of the developed alloys could be attributed to the increase of castability and the decrease of porosity level over the existing commercially available A356 and A357 alloys.
In a variation on the above-noted single step ageing treatment, a two-step ageing treatment consisting of an initial step of 150 °C for 2 hours followed by ageing at 180 °C for 6 hours was applied to the alloys. As ageing time progresses, the alloys attain yield levels that exceed that of aged at a single stage ageing. It is evident that a two-step ageing treatment could further widen the gap between the new alloys and the existing commercial alloy castings. The mechanical properties of the developed alloys labelled as GCOl and GC02 under solution and two-step ageing treatment are also listed in Table 2.
TABLE 2
Table 2 Mechanical properties of the permanent mold casting alloys in EXAMPLE 1 after heat treatment.
Yield strength UTS Elongation
Alloy Heat treatment
(MPa) (MPa) (%)
A356(Al-7Si-0.35Mg) 540°C/8h+170°C/8h 250 310 8.5
A357(Al-7Si-0.5Mg) 540°C/8h+170°C/8h 285 340 5.0
GC01(Al-9.2Si-0.5Mg) 540°C/8h+170°C/8h 312 365 11.2
GC02(Al-9.7Si-0.5Mg) 540°C/8h+170°C/8h 316 370 10.2
GC01(Al-9.2Si-0.5Mg) 540°C/8h+150°C/2h+180°C/6h 317 370 10.8
GC02(Al-9.7Si-0.5Mg) 540°C/8h+150°C/2h+180°C/6h 321 374 10.1 EXAMPLE 2: Sand casting
Four alloys of the compositions listed in Table 3 were cast into a sand mold. The alloys also include an A356 and an A357 type cast aluminum alloys. The castings were made by weighting different elements with an appropriate ratio and melting them in a 12 kg clay- graphite crucible in an electric resistance furnace. When the melt was fully homogenised, it was subjected to degassing, during which Ar was blown into the melt by a commercial rotatory degasser adjusted at 350 rpm for 4 min. It should be mentioned that Al-lOSr alloy was added at 0.01-0.02 wt.% Sr before degassing. TiB-containing refiner was added at 720 °C with 0.005 wt.% of B and before pouring. Thereafter, the melt was poured into the British standard sand mould, to produce dog-bone shape tensile specimens. In a gravity casting using sand mold, molten metal was poured into the sand mold which was at room temperature. Chemical composition analysis was carried out using the Foundry-Master Pro which is a high-performing optical emission spectrometer (OES).
Each of the four castings was solution heat treated at 540 °C for 8 hours, immediately quenched into ambient temperature water upon removal from the furnace and allowed to stabilize for several days. Ageing was optimized for each alloy by taking Vickers hardness measurements in accordance with the American Society for Testing and Materials (ASTM) standard E92-82 at selected time intervals for a wide range of temperatures. The optimized ageing process is at 170 °C for 8 hours or at 190°C for 4 hours. The mechanical properties were further measured in accordance with ASTM B557 standard using an Instron 5500 Universal Electromechanical Testing Systems equipped with Bluehill software and a ±50 kN load cell. All the tensile tests were performed at ambient temperature (~ 25 °C). The gauge length of the extensometer was 50 mm and the ramp rate for extension was 1 mm/min. The mechanical properties of the four castings after solution and ageing treatment are listed in Table 4. TABLE 3
Table 3 Chemical composition of the alloys in EXAMPLE2.
Alloy Si Mg Cu Fe Mn V Ti Sr B Al
A356 7.08 0.35 0.00 0.11 0.06 0.016 0.14 0.015 0.002 Balance
A357 7.05 0.50 0.00 0.11 0.06 0.016 0.14 0.015 0.002 Balance
SCOl 9.14 0.50 0.00 0.11 0.06 0.016 0.14 0.015 0.005 Balance
SC02 9.76 0.50 0.00 0.11 0.07 0.016 0.14 0.015 0.005 Balance
As shown in Table 4, the commercially available A356 alloy displays a yield strength of 230 MPa and an UTS of 280 MPa with 0.35 wt.% Mg, and the commercially available A357 alloy shows a yield strength of 275 MPa and an UTS of 300 MPa with 0.5 wt.% Mg, while the developed alloys labelled SCOl and SC02 with 0.5 wt.% Mg display a remarkable increase of strength over the commercially available A356 and A357 alloys, with a yield strength above 295 MPa and an UTS above 325MPa. This is especially surprising given that the A357 alloy is by far the highest strength alloy in the Al-Si-Mg cast alloy system. More importantly, the Mg content is higher in the A357 alloy, in which Mg content is 0.5-0.7 wt.%, and the A357 alloy achieves higher strength over the A356 alloy at higher Mg content with significant decrease of elongation to be below 3 %, while the developed alloys achieve higher strength over the A356 alloy without obvious decrease of elongation. Clearly, the developed compositions are very potent in overcoming this large property disparity that is observed with slightly different Mg levels. If the Mg content were adjusted to the 0.60 weight percent level or above, it is likely that the strength of the developed alloys would be even greater.
In a variation on the above-noted single step ageing treatment, a two-step ageing treatment consisting of an initial step of 150 °C for 2 hours followed by ageing at 180 °C for 6 hours was applied to the alloys. As ageing time progresses, the alloys attain yield levels that exceed that of aged at a single stage ageing. It is evident that a two-step ageing treatment could further widen the gap between the new alloys and the existing commercial alloy castings. The mechanical properties of the developed alloys labelled as SCOl and SC02 under solution and two-step ageing treatment are also listed in Table 4. TABLE 4
Table 4 Mechanical properties of the sand mold casting alloys in EXAMPLE2 after heat treatment.
Yield strength UTS
Alloy Heat treatment Elongation (%)
(MPa) (MPa)
A356(Al-7Si-0.35Mg) 540°C/8h+170°C/8h 230 280 4.5
A357(Al-7Si-0.5Mg) 540°C/8h+170°C/8h 275 300 3.0
SC01(Al-9.1Si-0.5Mg) 540°C/8h+170°C/8h 300 325 4.5
SC02(Al-9.8Si-0.5Mg) 540°C/8h+170°C/8h 305 330 4.0
SC01(Al-9.1Si-0.5Mg) 540°C/8h+150°C/2h+180°C/6h 305 331 4.5
SC01(Al-9.8Si-0.5Mg) 540°C/8h+150°C/2h+180°C/6h 310 335 4.0 All optional and preferred features and modifications of the described embodiments and dependent claims are usable in all aspects of the invention taught herein. Furthermore, the individual features of the dependent claims, as well as all optional and preferred features and modifications of the described embodiments are combinable and interchangeable with one another.
The disclosures in UK patent application number 1713005.5, from which this application claims priority, and in the abstract accompanying this application are incorporated herein by reference.

Claims

1. A method of forming a cast aluminium alloy, including the steps of:
(i) providing an aluminium alloy including
from 8.5 to 12.5 wt.% Si,
from 0.4 to 1.0 wt.% Mg,
up to 0.2 wt.% Ti,
from 0.05 to 0.25 wt.% Mn,
from 0.002 to 0.04 wt.% Sr,
from 0.001 to 0.1 wt.% B
and other impurity elements of Cu, Fe, Zn, each at less than 0.15 wt.% with the balance being Al and incidental impurities;
(ii) melting said alloy;
(iii) degassing the alloy melt by introducing into the melt a gas including at least one of nitrogen, argon or chlorine or a mixture thereof in order to reduce dissolved hydrogen in the melt to a level of less than 0.7 mL/100 g melt;
(iv) cleaning the alloy melt by adding 25% Na2SiF6 and 75% C2C16 refining agents in an amount from 0.01-0.8 wt.%;
(v) adding a grain refiner in the form of a TiB-containing master alloy, a B-containing master alloy, or an Al-B master alloys with the boron content up to 0.1 wt.% B; (vi) refining and modifying the eutectic silicon phase by adding from 0.002 to 0.04 wt.% Sr in the form of an Al-Sr master alloys;
(vii) carrying out a solution heat treatment at a temperature from 520 °C to 545 °C for a time from 2 h to 12 h; and
(viii) carrying out an ageing heat treatment at a temperature from 170 °C to 200 °C for a time from 2 h to 8 h.
2. A method as claimed in claim 1, wherein the alloy of step (i) includes
from 8.5 to 10.0 wt.% Si, from 0.45 to 0.65 wt.% Mg,
from 0.1 to 0.15 wt.% Ti,
less than 0.15 wt.% Mn,
from 0.008 to 0.02 wt.% Sr,
from 0.004 to 0.04 wt.% B
and other impurity elements of Cu, Fe, Zn, each at less than 0.15 wt.% and the balance of Al and incidental impurities
3. A method as claimed in any preceding claim, wherein the dissolved hydrogen in step (iii) is reduced to a level of less than 0.2 mL/100 g melt.
4. A method as claimed in any preceding claim, wherein the grain refiner of step (v) includes up to 3.5 wt.% Α13ΤΪ3Β or Α11ΤΪ3Β.
5. A method as claimed in any preceding claim, wherein the grain refiner of step (v) has a B content from 0.004 to 0.04 wt.%.
6. A method as claimed in any preceding claim, wherein in step (vi) the amount of Sr is from 0.008 to 0.02wt.%.
7. A method as claimed in any preceding claim, wherein the solution heat treatment of step (vii) is carried out at a temperature from 535 °C to 540 °C for a time from 8 h to 10 h.
8. A method as claimed in any preceding claim, wherein the ageing heat treatment of step (viii) is carried out at a temperature of about 170 °C from 7 h to 8 h.
9. A method as claimed in of claims 1 to 7, wherein the ageing heat treatment of step (viii) is carried out at a temperature from 180 to 190 °C from 2 h to 5 h.
10. An aluminium alloy including from 8.5 to 12.5 wt.% Si, from 0.46 to 1.0 wt.% Mg, from 0.1 to 0.2 wt.% Ti, from 0.05 to 0.25 wt.% Mn, and less than 0.05 wt.% Sn, the balance being Al and incidental impurities.
11. An aluminium alloy as claimed in claim 10, further include grain refining additions of Ti, TiB2, A1B2, B, Be, Zr, Y, V, Nb, singly or in combination with one another in the range from 0.001 to 1.0 wt.%, chemical modifiers such as Na and Sr, singly or in combination with one another in the range of from 0.001 to about 0.10 wt.% and phase refiners such as P in the range from 0.01 to 0.30 wt.%.
EP18765965.1A 2017-08-14 2018-07-31 Method of forming a cast aluminium alloy Pending EP3669011A1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
GBGB1713005.5A GB201713005D0 (en) 2017-08-14 2017-08-14 The alloy and manufacturing method of Al-Si-Mg castings for improved mechanical performance
PCT/GB2018/052186 WO2019034837A1 (en) 2017-08-14 2018-07-31 Method of forming a cast aluminium alloy

Publications (1)

Publication Number Publication Date
EP3669011A1 true EP3669011A1 (en) 2020-06-24

Family

ID=59896136

Family Applications (1)

Application Number Title Priority Date Filing Date
EP18765965.1A Pending EP3669011A1 (en) 2017-08-14 2018-07-31 Method of forming a cast aluminium alloy

Country Status (5)

Country Link
US (1) US20200190634A1 (en)
EP (1) EP3669011A1 (en)
CN (1) CN111032897A (en)
GB (1) GB201713005D0 (en)
WO (1) WO2019034837A1 (en)

Families Citing this family (38)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN109943754A (en) * 2019-03-28 2019-06-28 帅翼驰新材料集团有限公司 A kind of preparation method of cast aluminium alloy gold
CN111809083B (en) * 2019-04-12 2022-06-24 通用汽车环球科技运作有限责任公司 Aluminum alloy composition for simplifying semi-solid casting process and semi-solid casting method
CN111719070A (en) * 2020-06-29 2020-09-29 苏州慧金新材料科技有限公司 High-strength die-casting aluminum alloy material for mobile phone middle plate and preparation method thereof
CN113862531A (en) * 2020-06-30 2021-12-31 比亚迪股份有限公司 Aluminum alloy and preparation method thereof
CN111809085A (en) * 2020-07-15 2020-10-23 宣城建永精密金属有限公司 High-voltage electrical system transmission case and casting process thereof
CN111910094A (en) * 2020-07-18 2020-11-10 江苏雷科德轨道交通科技有限公司 Preparation process of aluminum alloy for high-elongation gear box
CN111926222B (en) * 2020-08-25 2021-11-30 肇庆南都再生铝业有限公司 Heat-resistant regenerated die-casting aluminum alloy and preparation method thereof
CN114182141A (en) * 2020-09-14 2022-03-15 济南科为达新材料科技有限公司 Novel high-strength and high-toughness heat-resistant aluminum-silicon casting alloy
CN112725643A (en) * 2020-12-01 2021-04-30 浙江富丽华铝业有限公司 Production process of aluminum profile for automobile collision energy-absorbing component
WO2022220534A1 (en) * 2021-04-13 2022-10-20 Lemon Metal Inc. Aluminum alloys
CN113444929A (en) * 2021-07-16 2021-09-28 合肥工业大学 Microalloying non-heat treatment high-strength and high-toughness die-casting aluminum alloy and preparation process thereof
CN114032426B (en) * 2021-11-04 2022-07-29 山西江淮重工有限责任公司 Secondary modification method for ZL114A alloy and obtained product thereof
CN114318183A (en) * 2021-12-30 2022-04-12 上海耀鸿科技股份有限公司 High-plasticity aluminum alloy part and preparation method thereof
CN114427054A (en) * 2022-01-20 2022-05-03 大连理工大学宁波研究院 A kind of aluminum alloy for high-speed train gear transmission system and its manufacturing method
CN114560019A (en) * 2022-02-25 2022-05-31 蔚来汽车科技(安徽)有限公司 Aluminum alloys and parts made therefrom
CN114672674B (en) * 2022-02-28 2024-03-15 中国第一汽车股份有限公司 Casting-rolling high-strength high-toughness aluminum-silicon alloy and preparation method thereof
CN114807651A (en) * 2022-05-26 2022-07-29 广东省科学院新材料研究所 high-Mg-content eutectic Al-Si alloy and preparation method and structural member thereof
CN114713798B (en) * 2022-06-09 2022-08-30 中国航发北京航空材料研究院 Vacuum mold-filling top-placing chilling pressurized solidification device and method for preparing large aluminum alloy casting
CN115044809B (en) * 2022-06-17 2023-05-05 大连科天新材料有限公司 Cast aluminum-silicon alloy, preparation method thereof and aluminum-silicon alloy for aviation or automobile castings
CN115044810B (en) * 2022-06-17 2023-05-09 大连科天新材料有限公司 A kind of aluminum alloy and preparation method thereof, automobile material
CN115141960B (en) * 2022-06-17 2023-05-23 中南大学 High-strength and high-toughness cast aluminum alloy with low Si content and preparation method thereof
CN114774812B (en) * 2022-06-22 2022-09-02 河北钢研德凯科技有限公司北京分公司 Hot isostatic pressing method for complex special-shaped aluminum alloy casting
CN115522103B (en) * 2022-10-31 2023-06-16 合肥工业大学 Novel refining modifier for hypoeutectic aluminum-silicon alloy and preparation and application methods thereof
CN115786786A (en) * 2022-11-17 2023-03-14 大连科天新材料有限公司 A kind of cast aluminum-copper alloy, its preparation method and application
CN115927922A (en) * 2022-11-25 2023-04-07 东莞理工学院 Aluminum alloy material and preparation and application thereof
CN115896560B (en) * 2022-12-02 2023-06-06 中科力祥科技股份有限公司 High-performance aluminum alloy material and preparation method thereof
CN116103543A (en) * 2022-12-29 2023-05-12 中铝广西有色稀土开发有限公司 A kind of recycled high thermal conductivity die-casting aluminum alloy containing rare earth elements and its preparation method
CN118291787A (en) * 2023-01-05 2024-07-05 通用汽车环球科技运作有限责任公司 Aluminum wheel and method for casting aluminum wheel using high scrap aluminum content
CN116240417A (en) * 2023-03-17 2023-06-09 昆明冶金研究院有限公司 Method for improving performance of cast aluminum-silicon alloy
CN116676513A (en) * 2023-04-27 2023-09-01 重庆大学 Preparation method of cast aluminum-silicon alloy
CN116555639A (en) * 2023-04-28 2023-08-08 山东大学 High-strength and high-toughness cast aluminum alloy and preparation method thereof
CN116970847B (en) * 2023-07-24 2024-05-28 东莞理工学院 A high-strength, low-defect Al-Si alloy and its preparation method and application
CN117165820A (en) * 2023-10-17 2023-12-05 南通众福新材料科技有限公司 Liquid casting aluminum alloy for high-vacuum die casting and method
CN117448634B (en) * 2023-10-30 2024-05-14 河北新立中有色金属集团有限公司 Renewable high-strength and high-toughness heat-treatment-free aluminum alloy and preparation method and die casting process thereof
CN117845105B (en) * 2023-12-06 2024-12-10 苏州大学 A high-strength and tough cast aluminum alloy and its preparation method and application
CN117904497B (en) * 2024-01-19 2025-01-21 哈尔滨工业大学 A high-strength and tough cast aluminum alloy with low copper content and preparation method thereof
CN118256783B (en) * 2024-04-12 2025-08-26 西安工业大学 A high-strength and tough cast Al-Cu alloy material and its preparation method
CN118703841B (en) * 2024-08-30 2025-01-07 包头盛泰汽车零部件制造有限公司 Rare earth modified aluminum alloy and preparation method and application thereof

Family Cites Families (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2001123239A (en) 1999-10-21 2001-05-08 Daiki Aluminium Industry Co Ltd Aluminum alloy and cast aluminum alloy for high strength casting
DE10323741B3 (en) 2003-05-24 2004-10-14 Daimlerchrysler Ag Aluminum casting alloy for the production of e.g. pistons of IC engines contains alloying additions of silicon, magnesium, zirconium, hafnium and titanium
US6921512B2 (en) * 2003-06-24 2005-07-26 General Motors Corporation Aluminum alloy for engine blocks
CN1266297C (en) * 2003-11-20 2006-07-26 上海交通大学 In-situ synthesized TiC-AI composite ultra-fine grain refining agent and process for preparing same
US20050167012A1 (en) * 2004-01-09 2005-08-04 Lin Jen C. Al-Si-Mn-Mg alloy for forming automotive structural parts by casting and T5 heat treatment
EP2298947B1 (en) 2008-07-09 2015-01-28 Guizhou Aluminums Factory High strength casting aluminium alloy material
WO2013041584A2 (en) * 2011-09-19 2013-03-28 Alcoa Gmbh Improved aluminum casting alloys containing vanadium
US9771635B2 (en) * 2012-07-10 2017-09-26 GM Global Technology Operations LLC Cast aluminum alloy for structural components
EP2865772B1 (en) 2013-10-23 2016-04-13 Befesa Aluminio, S.L. Aluminium casting alloy
GB201402323D0 (en) * 2014-02-11 2014-03-26 Univ Brunel A high strength cast aluminium alloy for high pressure die casting
CN105441737A (en) * 2015-12-01 2016-03-30 上海交通大学 High-strength high-corrosion-resistance cast aluminum alloy and gravity casting manufacturing method thereof

Also Published As

Publication number Publication date
GB201713005D0 (en) 2017-09-27
US20200190634A1 (en) 2020-06-18
CN111032897A (en) 2020-04-17
WO2019034837A1 (en) 2019-02-21

Similar Documents

Publication Publication Date Title
US20200190634A1 (en) Method of forming a cast aluminium alloy
EP1897962B1 (en) Creep resistant magnesium alloy with improved ductility and fracture toughness for gravity casting applications
US10458009B2 (en) Free-machining wrought aluminium alloy product and manufacturing process thereof
EP1329530B1 (en) High temperature resistant magnesium alloys
JP7152977B2 (en) aluminum alloy
JP6496809B2 (en) Creep-resistant, ductile magnesium alloy for die casting
US11401586B2 (en) High-strength A356 alloy and preparation method thereof
CN112143945B (en) A kind of high-strength and toughness cast aluminum-silicon alloy with multiple rare earth elements and preparation method thereof
WO2016034857A1 (en) A casting al-mg-zn-si based aluminium alloy for improved mechanical performance
GB2500825A (en) An Al-Mg-Si-Mn alloy and a method of producing such an alloy
CN104073699A (en) Al-Si-Cu-Mg cast aluminum alloy and preparation method thereof
RU2165995C1 (en) Highly string aluminium-based alloy and product made of said alloy
CN116057193B (en) Aluminum Casting Alloy
EP3927861A1 (en) A magnesium alloy, a piston manufactured by said magnesium alloy and a method for manufacturing said piston
KR102589799B1 (en) High-strength aluminum-based alloys and methods for producing articles therefrom
US20030084968A1 (en) High strength creep resistant magnesium alloys
EP1477577B1 (en) Aluminum alloy, cast article of aluminum alloy, and method for producing cast article of aluminum alloy
JP4526768B2 (en) Magnesium alloy
JP2004238678A (en) Magnesium alloy
CN103060644B (en) Aluminum alloy material processed by cyano complex and preparation method of aluminum alloy material
Okamoto et al. Applicability of Mg-Zn-(Y, Gd) alloys for engine pistons
JPH0835030A (en) Aluminum alloy for casting, excellent in strength
EP4596733A1 (en) Aluminium casting alloy
CN108179337B (en) High temperature creep resistant die-casting magnesium alloy and die-casting method thereof
JPH10324938A (en) Zinc / copper / aluminum alloy and its die-cast

Legal Events

Date Code Title Description
STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: UNKNOWN

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: THE INTERNATIONAL PUBLICATION HAS BEEN MADE

PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: REQUEST FOR EXAMINATION WAS MADE

17P Request for examination filed

Effective date: 20200115

AK Designated contracting states

Kind code of ref document: A1

Designated state(s): AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO RS SE SI SK SM TR

AX Request for extension of the european patent

Extension state: BA ME

DAV Request for validation of the european patent (deleted)
DAX Request for extension of the european patent (deleted)
STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: EXAMINATION IS IN PROGRESS

17Q First examination report despatched

Effective date: 20240712