EP0366134B1 - Aluminum alloy useful in powder metallurgy process - Google Patents

Aluminum alloy useful in powder metallurgy process Download PDF

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Publication number
EP0366134B1
EP0366134B1 EP89119912A EP89119912A EP0366134B1 EP 0366134 B1 EP0366134 B1 EP 0366134B1 EP 89119912 A EP89119912 A EP 89119912A EP 89119912 A EP89119912 A EP 89119912A EP 0366134 B1 EP0366134 B1 EP 0366134B1
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EP
European Patent Office
Prior art keywords
aluminum alloy
weight
extruded
aluminum
resistance
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.)
Expired - Lifetime
Application number
EP89119912A
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German (de)
French (fr)
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EP0366134A1 (en
Inventor
Jun Kusui
Masahiko Kawai
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.)
Toyo Aluminum KK
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Toyo Aluminum KK
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Filing date
Publication date
Priority claimed from JP1265610A external-priority patent/JPH03177530A/en
Application filed by Toyo Aluminum KK filed Critical Toyo Aluminum KK
Publication of EP0366134A1 publication Critical patent/EP0366134A1/en
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Classifications

    • CCHEMISTRY; METALLURGY
    • C22METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22CALLOYS
    • C22C1/00Making non-ferrous alloys
    • C22C1/04Making non-ferrous alloys by powder metallurgy
    • C22C1/0408Light metal alloys
    • C22C1/0416Aluminium-based alloys
    • CCHEMISTRY; METALLURGY
    • C22METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22CALLOYS
    • C22C21/00Alloys based on aluminium
    • C22C21/02Alloys based on aluminium with silicon as the next major constituent

Definitions

  • the present invention relates to an aluminum alloy which provides a product having a highly improved strength at elevated temperatures and remarkable resistance to creep when used in powder metallurgy process.
  • Products of an aluminum alloy prepared by a powder metallurgy process exhibit highly improved heat resistance, wear resistance, and like properties in comparison with the products prepared by an ingot metallurgy process (hereinafter referred to as "IM process") because the products by the P/M process can contain additional elements in larger amounts with no segregation and being more uniformly dispersed in the aluminum matrix than the products prepared by the IM process.
  • P/M aluminum alloy products are usually produced by hot extrusion of a powdery, flaky or ribbon-like quickly solidified material to obtain a billet and processing the billet to the desired shapes or forms.
  • the oxide films on the surfaces of the powder particles, flakes or ribbons are fractured and the exposed inner aluminum portions are pressed against each other to form strong bonding.
  • aluminum oxide films are fractured; however, since the shearing force is relatively small and deformation of each particle is not so large and uniform as in the case of extrusion, the bond between particles is not so strong as in the extruded product.
  • the extrusion ratio in conducting the above extrusion by the P/M process is usually 10 or more, preferably 20 or more to obtain a strong bonding of each particle.
  • the extrusion by the P/M process usually requires much higher forces than the extrusion by the IM process because the aluminum alloy used in the former process contains larger amounts of alloying elements. For these limitations, aluminum alloy materials obtained by the P/M process are difficult to employ for producing large-sized products.
  • aluminum alloys conventionally used in the P/M process give a product which cannot fully meet the severe requirements such as high strengths at elevated temperatures up to 300°C, high resistance to creep, etc.
  • US-A-3325279 relates to aluminum high silicon alloys and discloses an alloy containing 29% Si, 3.6% Fe and 2.7% Ti, with the balance Al.
  • EP-A-0341714 (document in accordance with Article 54(3) EPC) discloses an aluminum alloy containing 25% Si, 3% Fe, 5% Ni and 1% Mo produced by a P/M process and extruded at 450°C at varying extrusion ratios between 3:1 and 20:1.
  • An object of the invention is to provide a P/M aluminum alloy which can be extruded under a low extrusion ratio of 10 or lower.
  • Another object of the invention is to provide a P/M aluminum alloy which can be extruded even under an extremely low extrusion ratio of 2 to 5.
  • Still another object of the invention is to provide a P/M aluminum alloy capable of producing an extruded product excellent in strength at high temperatures and resistance to creep.
  • the powder particles are strongly bonded to each other even at a low extrusion ratio and the extruded material exhibits substantially uniform strength and elongation irrespective of the extrusion ratio. If an aluminum alloy powder with the composition outside the specified range is used, an extruded material with strong bonding cannot be obtained at a low extrusion ratio of 10 or 5 to 2 at a temperature of 400 to 500°C.
  • the amount of Si is less than 5% by weight of the alloy, the bonding strength of the particles is low; whereas the use of Si of more than 30% by weight results in the excess volume of primary Si particles in the matrix which leads to a reduction in the toughness of the alloy.
  • Fe, Ni, Cr and Mn mainly contribute to the improvement of heat resistance and strength.
  • the amount of at least one of Fe, Ni, Cr and Mn in less than 0.5% by weight results in inferior heat resistance and strength of the extruded material whereas the amount thereof in more than 10% by weight results in lower toughness with the formation of coarse intermetallic compounds.
  • the total amount of these alloying elements in excess of 20% by weight also leads to a reduction of toughness of the alloy.
  • Mo, Zr, V and Ti mainly contribute to the improvement of heat resistance and creep resistance.
  • the amount of at least one of Mo, Zr, V and Ti in less than 0.3% by weight does not significantly improve the resistance to heat and creep.
  • the amount thereof exceeds 3% by weight coarse intermetallic compounds are formed to lower the toughness of the alloy.
  • the total amount is up to 5% by weight of the alloy to prevent the formation of coarse intermetallic compounds which lead to reduced toughness.
  • the aluminum alloy of the invention contains 5 to 30% by weight of Si, 2 to 5% by of Fe, 2 to 5% by weight of Ni, 0.5 to 3% by weight of Mo and 0.5 to 3% by weight of Zr provided that the total amount of Mo and Zr is more than 2% by weight and less than 5% by weight.
  • the aluminum alloy of the invention containing alloying elements in the above ranges shows much more balanced properties of the improved strength, toughness and resistance to creep at elevated temperatures.
  • the aluminum alloys with alloying elements in the above range are most useful as the materials for machine components, etc.
  • the extruded product formed from the aluminum alloy of the invention exhibits high resistance to heat and creep.
  • Table 1 Aluminum alloys containing alloying elements as indicated in Table 1 below were air-atomized into particles and sieved to prepare powders by passing through sieve openings of 150 ⁇ m x 100 ⁇ m (powders of minus 100 mesh).
  • Each of the aluminum alloy powders thus prepared was cold pressed to a preform 30 mm in diameter and 80 mm in height and then extruded at 450°C at an extrusion ratio of 3. Test pieces were prepared from the extruded materials, and tensile tests and creep tests were conducted at 300°C.
  • rupture time indicates the period of time required for a test piece to rupture when it is exposed to a stress of 78.4 MPa(8 kg/mm2) at 300°C.
  • Table 2 indicates that the extruded materials obtained from the aluminum alloys of the invention have high tensile strength and elongation and exhibit good resistance to creep. Particularly, the extruded products produced from alloy Nos.13 to 16 are better balanced in resistance to creep, tensile strength at elevated temperatures and toughness.

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  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Materials Engineering (AREA)
  • Mechanical Engineering (AREA)
  • Metallurgy (AREA)
  • Organic Chemistry (AREA)
  • Powder Metallurgy (AREA)

Description

  • The present invention relates to an aluminum alloy which provides a product having a highly improved strength at elevated temperatures and remarkable resistance to creep when used in powder metallurgy process.
  • Products of an aluminum alloy prepared by a powder metallurgy process (hereinafter referred to as "P/M process") exhibit highly improved heat resistance, wear resistance, and like properties in comparison with the products prepared by an ingot metallurgy process (hereinafter referred to as "IM process") because the products by the P/M process can contain additional elements in larger amounts with no segregation and being more uniformly dispersed in the aluminum matrix than the products prepared by the IM process.
  • Conventional P/M aluminum alloy products are usually produced by hot extrusion of a powdery, flaky or ribbon-like quickly solidified material to obtain a billet and processing the billet to the desired shapes or forms. During the hot extrusion step, the oxide films on the surfaces of the powder particles, flakes or ribbons are fractured and the exposed inner aluminum portions are pressed against each other to form strong bonding. In a powder-rolling process and a powder-forging process which also belong to a general category of the P/M process, aluminum oxide films are fractured; however, since the shearing force is relatively small and deformation of each particle is not so large and uniform as in the case of extrusion, the bond between particles is not so strong as in the extruded product.
  • The extrusion ratio in conducting the above extrusion by the P/M process is usually 10 or more, preferably 20 or more to obtain a strong bonding of each particle. The extrusion by the P/M process usually requires much higher forces than the extrusion by the IM process because the aluminum alloy used in the former process contains larger amounts of alloying elements. For these limitations, aluminum alloy materials obtained by the P/M process are difficult to employ for producing large-sized products.
  • Further, aluminum alloys conventionally used in the P/M process give a product which cannot fully meet the severe requirements such as high strengths at elevated temperatures up to 300°C, high resistance to creep, etc.
  • US-A-3325279 relates to aluminum high silicon alloys and discloses an alloy containing 29% Si, 3.6% Fe and 2.7% Ti, with the balance Al.
  • EP-A-0341714 (document in accordance with Article 54(3) EPC) discloses an aluminum alloy containing 25% Si, 3% Fe, 5% Ni and 1% Mo produced by a P/M process and extruded at 450°C at varying extrusion ratios between 3:1 and 20:1.
  • An object of the the invention is to provide a P/M aluminum alloy which can be extruded under a low extrusion ratio of 10 or lower.
  • Another object of the invention is to provide a P/M aluminum alloy which can be extruded even under an extremely low extrusion ratio of 2 to 5.
  • Still another object of the invention is to provide a P/M aluminum alloy capable of producing an extruded product excellent in strength at high temperatures and resistance to creep.
  • These objects are achieved by the aluminum alloy and product according to the claims:
       Other objects and features of the invention will become apparent from the following description.
  • We conducted extensive research to obviate the prior art problems as mentioned above and found that these problems can be markedly alleviated by use of a powdery aluminum alloy comprising specific alloying elements. The present invention has been accomplished on the basis of this novel finding.
  • When the aluminum alloys of the invention comprising specific components are extruded, the powder particles are strongly bonded to each other even at a low extrusion ratio and the extruded material exhibits substantially uniform strength and elongation irrespective of the extrusion ratio. If an aluminum alloy powder with the composition outside the specified range is used, an extruded material with strong bonding cannot be obtained at a low extrusion ratio of 10 or 5 to 2 at a temperature of 400 to 500°C.
  • Stated more specifically, if the amount of Si is less than 5% by weight of the alloy, the bonding strength of the particles is low; whereas the use of Si of more than 30% by weight results in the excess volume of primary Si particles in the matrix which leads to a reduction in the toughness of the alloy.
  • Fe, Ni, Cr and Mn mainly contribute to the improvement of heat resistance and strength. The amount of at least one of Fe, Ni, Cr and Mn in less than 0.5% by weight results in inferior heat resistance and strength of the extruded material whereas the amount thereof in more than 10% by weight results in lower toughness with the formation of coarse intermetallic compounds. The total amount of these alloying elements in excess of 20% by weight also leads to a reduction of toughness of the alloy.
  • Mo, Zr, V and Ti mainly contribute to the improvement of heat resistance and creep resistance. The amount of at least one of Mo, Zr, V and Ti in less than 0.3% by weight does not significantly improve the resistance to heat and creep. On the other hand, when the amount thereof exceeds 3% by weight, coarse intermetallic compounds are formed to lower the toughness of the alloy. When two or more of Mo, Zr, V and Ti are used, the total amount is up to 5% by weight of the alloy to prevent the formation of coarse intermetallic compounds which lead to reduced toughness.
  • The aluminum alloy of the invention contains 5 to 30% by weight of Si, 2 to 5% by of Fe, 2 to 5% by weight of Ni, 0.5 to 3% by weight of Mo and 0.5 to 3% by weight of Zr provided that the total amount of Mo and Zr is more than 2% by weight and less than 5% by weight.
  • The aluminum alloy of the invention containing alloying elements in the above ranges shows much more balanced properties of the improved strength, toughness and resistance to creep at elevated temperatures. Thus, the aluminum alloys with alloying elements in the above range are most useful as the materials for machine components, etc.
  • When the aluminum alloy of the invention is extruded at a temperature between 400 to 500°C, a very strong bond can be produced in an extruded material at a low extrusion ratio of 10 or less, or even at a very low extrusion ratio of 2 to 5.
  • The extruded product formed from the aluminum alloy of the invention exhibits high resistance to heat and creep.
  • EXAMPLES
  • Given below are Examples to clarify the features of the invention in greater detail.
  • Example 1
  • Aluminum alloys containing alloying elements as indicated in Table 1 below were air-atomized into particles and sieved to prepare powders by passing through sieve openings of 150µm x 100µm (powders of minus 100 mesh). Table 1
    No. Alloying Elements (wt.%)
    Si Fe Ni Cr Mn Mo Zr V Ti
    1 6 5 3 2
    2 12 1 1 1 1 2
    3 12 5 3 0.7
    4 12 5 3 2
    5 12 5 3 2
    6 12 5 3 2
    7 12 5 3 2
    8 17 5 3 1
    9 17 5 3 1
    10 20 3 3 2
    11 20 5 3 1
    12 25 4 5 1
    13 12 5 3 2.5
    14 12 5 3 1 1.5
    15 12 5 3 2 1.5
    16 12 5 3 2.5 1.5
    17 12 5 3
    18 17 3 3
    19 12 0.3 0.1 2 2
    20 1.2 1.0 (Cu=2.5 Mg=1.5) 0.1
  • Each of the aluminum alloy powders thus prepared was cold pressed to a preform 30 mm in diameter and 80 mm in height and then extruded at 450°C at an extrusion ratio of 3. Test pieces were prepared from the extruded materials, and tensile tests and creep tests were conducted at 300°C.
  • In Table 2, "rupture time" indicates the period of time required for a test piece to rupture when it is exposed to a stress of 78.4 MPa(8 kg/mm²) at 300°C.
  • Results are given in Table 2 below. Table 2
    No. Tensile strength (MPa) (kg/mm²) Elongation (%) Rupture time (Hr)
    1 198.9 (20.3) 11.0 1020
    2 208.7 (21.3) 13.0 1187
    3 203.8 (20.8) 12.5 258
    4 215.6 (22.0) 10.5 3610
    5 225.4 (23.0) 4.2 105
    6 217.6 (22.2) 2.3 421
    7 220.5 (22.5) 1.5 358
    8 245.0 (25.0) 1.8 2563
    9 208.7 (21.3) 5.9 125
    10 227.4 (23.2) 1.2 2054
    11 243.0 (24.8) 1.8 1823
    12 230.3 (23.5) 1.9 435
    13 240.1 (24.5) 9.1 4350
    14 242.1 (24.7) 8.9 2895
    15 255.8 (26.1) 7.1 4568
    16 265,6 (27.1) 4.5 5015
    17 191.1 (19.5) 15.7 2.6
    18 198.9 (20.3) 15.3 2.2
    19 139.2 (14.2) 17.9 0.3
    20 96.0 (9.8) 22.7 1.3
  • Table 2 indicates that the extruded materials obtained from the aluminum alloys of the invention have high tensile strength and elongation and exhibit good resistance to creep. Particularly, the extruded products produced from alloy Nos.13 to 16 are better balanced in resistance to creep, tensile strength at elevated temperatures and toughness.
  • In contrast, aluminum alloys containing alloying elements in amounts outside the range of the invention give products low in tensile strength at 300°C and short in rupture time. It is noted that the alloy No.20 which is known to be highly resistant to heat among conventional IM materials is extremely inferior to the alloys of the invention in the strength and resistance to creep at 300°C.

Claims (4)

  1. An aluminum alloy comprising 5 to 30% by weight of Si, 2 to 5% by weight of Fe, 2 to 5% by weight of Ni, 0.5 to 3% by weight of Mo, 0.5 to 3% by weight of Zr and aluminum in a remaining amount provided that the total amount of Mo and Zr is in the range of more than 2% by weight and less than 5% by weight.
  2. An aluminum alloy product produced by extruding an aluminum alloy material in powdery form, the aluminum alloy having a composition according to claim 1.
  3. An aluminum alloy product according to claim 2 wherein the aluminum alloy material is extruded at a temperature between 400 to 500°C and at an extrusion ratio of 2 to 10.
  4. An aluminum alloy product according to claim 3 wherein the aluminum alloy material is extruded at an extrusion ratio of 2 to 5.
EP89119912A 1988-10-27 1989-10-26 Aluminum alloy useful in powder metallurgy process Expired - Lifetime EP0366134B1 (en)

Applications Claiming Priority (6)

Application Number Priority Date Filing Date Title
JP272167/88 1988-10-27
JP27216788 1988-10-27
JP25432489 1989-09-28
JP254324/89U 1989-09-28
JP1265610A JPH03177530A (en) 1988-10-27 1989-10-11 Heat-resistant and creep-resistant aluminum alloy
JP265610/89U 1989-10-11

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EP0366134A1 EP0366134A1 (en) 1990-05-02
EP0366134B1 true EP0366134B1 (en) 1994-01-19

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Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN111051549A (en) * 2017-04-05 2020-04-21 阿马格铸造公司 Raw material, application thereof and additive manufacturing method using raw material
CN111534727A (en) * 2020-05-07 2020-08-14 江苏兆铝金属制品有限公司 Special aluminum alloy material for high-strength car lamp and preparation method thereof

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* Cited by examiner, † Cited by third party
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JPH05311302A (en) * 1991-10-22 1993-11-22 Toyota Motor Corp Aluminum alloy excellent in strength at high temperature and wear resistance and reduced in friction
DE69311412T2 (en) * 1992-03-04 1998-01-02 Toyota Motor Co Ltd Heat-resistant aluminum alloy powder, heat-resistant aluminum alloy and heat-resistant and wear-resistant composite material based on aluminum alloy
EP0566098B1 (en) * 1992-04-16 1997-01-22 Toyota Jidosha Kabushiki Kaisha Heat resistant aluminum alloy powder, heat resistant aluminum alloy and heat and wear resistant aluminum alloy-based composite material
FR2690927B1 (en) * 1992-05-06 1995-06-16 Pechiney Aluminium ALUMINUM-BASED MOLDING ALLOYS HAVING GOOD RESISTANCE TO HOT CREAM.
DE69307848T2 (en) * 1992-12-03 1997-08-21 Toyota Motor Co Ltd Highly heat-resistant and wear-resistant aluminum alloy
DE19532253C2 (en) * 1995-09-01 1998-07-02 Peak Werkstoff Gmbh Process for the production of thin-walled pipes (II)
DE19532252C2 (en) * 1995-09-01 1999-12-02 Erbsloeh Ag Method of manufacturing bushings
DE19532244C2 (en) * 1995-09-01 1998-07-02 Peak Werkstoff Gmbh Process for the production of thin-walled tubes (I)
DE102004050484A1 (en) * 2004-10-15 2006-04-20 Peak Werkstoff Gmbh Alloy based on aluminum and molded part of this alloy
CN107034391B (en) * 2017-03-28 2018-12-25 龙口市大川活塞有限公司 A kind of aluminium alloys for pistons and preparation method thereof

Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0341714A1 (en) * 1988-05-12 1989-11-15 Sumitomo Electric Industries, Ltd. Method of forming large-sized aluminum alloy product

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* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3325279A (en) * 1965-12-03 1967-06-13 Dow Chemical Co Aluminum-high silicon alloys
US4135922A (en) * 1976-12-17 1979-01-23 Aluminum Company Of America Metal article and powder alloy and method for producing metal article from aluminum base powder alloy containing silicon and manganese
CA1230761A (en) * 1982-07-12 1987-12-29 Fumio Kiyota Heat-resistant, wear-resistant, and high-strength aluminum alloy powder and body shaped therefrom
FR2537656B1 (en) * 1982-12-08 1987-12-24 Pechiney Aluminium PISTON INSERTS OF DIESEL ENGINES OF ALUMINUM-SILICON ALLOYS HAVING IMPROVED HOT RESISTANCE AND WORKABILITY
FR2604186A1 (en) * 1986-09-22 1988-03-25 Peugeot PROCESS FOR MANUFACTURING HYPERSILICALLY ALUMINUM ALLOY PARTS OBTAINED FROM COOLED COOLED POWDERS AT HIGH SPEED

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0341714A1 (en) * 1988-05-12 1989-11-15 Sumitomo Electric Industries, Ltd. Method of forming large-sized aluminum alloy product

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN111051549A (en) * 2017-04-05 2020-04-21 阿马格铸造公司 Raw material, application thereof and additive manufacturing method using raw material
CN111051549B (en) * 2017-04-05 2022-02-22 阿马格铸造公司 Raw material, application thereof and additive manufacturing method using raw material
CN111534727A (en) * 2020-05-07 2020-08-14 江苏兆铝金属制品有限公司 Special aluminum alloy material for high-strength car lamp and preparation method thereof

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