EP0195341A1 - Aluminiumlegierungen mit hoher Korrosionsbeständigkeit und hoher Festigkeit - Google Patents

Aluminiumlegierungen mit hoher Korrosionsbeständigkeit und hoher Festigkeit Download PDF

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Publication number
EP0195341A1
EP0195341A1 EP86103164A EP86103164A EP0195341A1 EP 0195341 A1 EP0195341 A1 EP 0195341A1 EP 86103164 A EP86103164 A EP 86103164A EP 86103164 A EP86103164 A EP 86103164A EP 0195341 A1 EP0195341 A1 EP 0195341A1
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EP
European Patent Office
Prior art keywords
alloys
present
alloy
phase
aluminum
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.)
Withdrawn
Application number
EP86103164A
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English (en)
French (fr)
Inventor
Koji Hashimoto
Asahi Kawashima
Katsuhiko Asami
Shin-Ichirou Yoshida
Hideaki Yoshioka
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YKK Corp
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Yoshida Kogyo KK
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Priority claimed from JP60046497A external-priority patent/JPS61207541A/ja
Priority claimed from JP60174091A external-priority patent/JPS6237335A/ja
Application filed by Yoshida Kogyo KK filed Critical Yoshida Kogyo KK
Publication of EP0195341A1 publication Critical patent/EP0195341A1/de
Withdrawn legal-status Critical Current

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    • 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
    • C22C45/00—Amorphous alloys
    • C22C45/08—Amorphous alloys with aluminium as the major constituent

Definitions

  • the present invention relates to highly corrosion-resistant and high strength aluminum alloys produced by solidification through rapid quenching.
  • Aluminum is an important metal material which is light and inexpensive, and is easily processed and extensively used both in the elemental form and after being produced and fabricated by a variety of methods as an alloy.
  • aluminum and its alloys are highly susceptible to pitting corrosion under exposure to chloride-containing environments. Therefore, aluminum alloys, typically used as light alloys or sometimes as high strength light alloys depending on the composition, are not suitable for use in applications that require high corrosion resistance.
  • the low resistance to corrosion of aluminum alloys may be explained by the accelerated corrosion that occurs due to the inclusion and/or the secondary phases formed by impurity elements present in the alloys.
  • the addition of alloying elements effective in enhancing the corrosion resistance is impractical because they generally have narrow ranges for the formation of solid solutions.
  • the present inventors found that rapid solidification of molten alloys extended their solid solubility and sometimes led to the formation of amorphous alloys containing greater amounts of various elements than alloys produced by conventional methods, and that these amorphous alloys possessed extremely high corrosion resistance due to the chemically homogeneous nature of amorphous alloys and the addition of effective elements enhancing the corrosion resistance.
  • the present inventors found by further investigations that vitrification of aluminum alloys is difficult but rapid solidification of molten alloys containing prescribed amounts of appropriate elements results in the formation of highly corrosion-resistant, high strength alloys having high hardness and very high pitting potential which are characteristics of supersaturated solid solutions of very fine grains.
  • the present invention has been accomplished on the basis of this finding.
  • the present invention provides a highly corrosion-resistant and high strength aluminum alloy produced by rapid solidification of a melt that contains no less than 0.2 atomic% and no more than 15 atomic% of at least one element selected from the group consisting of Si, Ti, Zr, Nb, Ni, Cu and Mn and the balance of which is substantially composed of Al.
  • An aluminum melt having the composition specified above may be solidified by any of the rapid quenching techniques commonly employed in the production of amorphous alloys, which include the rotating wheel method wherein a molten metal is injected on to the outer surface of a rotating wheel, the centrifugal quenching method wherein the melt is impinged against the inner surface of the rotating cylinder, the double-roll method wherein a liquid metal is quenched by passage between two closely positioned rolls, - the gas method for making rapidly solidified flakes, the piston-anvil method, injecting a molten metal into a revolving chill medium for making a powder by rapid quenching, and other methods such as spraying and cavitation.
  • rapid quenching techniques commonly employed in the production of amorphous alloys, which include the rotating wheel method wherein a molten metal is injected on to the outer surface of a rotating wheel, the centrifugal quenching method wherein the melt is impinged against the inner surface of the rotating cylinder, the double-roll
  • the aluminum alloys of the present invention that are produced by rapid solidification of the compositions specified above have appreciably higher pitting potentials than the conventionally processed aluminum alloys. tn addition to this high corrosion-resistance, the aluminum alloys of the present invention exhibit high mechanical strength resulting from the formation of supersaturated solid solutions.
  • Fig. 1 is a diagrammatic view of the layout of the apparatus that may be used for the production of the rapidly solidified alloy of the present invention.
  • a suitable preparation method of rapidly solidified alloys of the present invention so called the rotating wheel method is as follows:
  • a quartz tube (2) has a nozzle (3) at its lower end in the vertical direction, and raw materials (4) and an inert gas for a jet of the raw materials melted are fed from the inlet (1).
  • a heater (5) is placed around the quartz tube (2) so as to heat the raw materials (4).
  • a high speed wheel (7) of 300 mm diameter is placed below the nozzle (3) and is rotated by a motor (6).
  • the apparatus is previously evacuated down to about 10- 5 torr and then exposed to an inert gas atmosphere such as argon or nitrogen.
  • the raw materials (4) having the specific compositions required are melted by the heater (5) in the quartz tube under an inert gas atmosphere.
  • the molten alloys impinge under the pressure of the inert gas of 0.4 -2 kg/cm 2 onto the outer surface of the wheel (7) which is rotated at a speed of 500 to 10,000 rpm whereby the rapidly solidified alloys are formed as long thin plates.
  • which may, for example, have thicknesses of 0.01 -0.1 mm, widths of 1 -10 mm and lengths of several to several tens of meters.
  • the criticality of each of the components in the aluminum alloy in accordance with the present invention is hereunder described.
  • the aforementioned elements Si, Ti, Zr, Nb, Ni, Cu and Mn are alloying elements which provide high corrosion resistance and mechanical strength by supersaturatedly dissolving in the a-AI phase which is the softest phase having the lowest corrosion resistance among phases in the aluminum alloys.
  • the corrosion resistance of the aluminum alloy prepared by rapid solidification is not sufficiently high and is not much different from that of rapidly solidified aluminum metal. If, on the other hand, the amount of at least one element selected from among Si, Ti, Zr, Nb, Ni, Cu and Mn exceeds 15 atomic%, the rapidly solidified alloy is too brittle to be used for practical purposes, except for the case where only Mn is added.
  • the amount of at least one element selected from among Si, Ti, Zr, Nb, Ni, Cu and Mn must be within the range of 0.2 - 1 5 atomic%.
  • the rapidly solidified aluminum alloy described above may contain no more than 4 atomic% of another element such as Mg, V, Cr, Fe, Co or Zn without sacrificing the objects of the present invention.
  • the elements added will be finely distributed along the boundaries of fine grains formed within the alloy as a result of rapid solidification and, hence, will prevent growth of these grains in subsequent heat treatments. Therefore, the aluminum alloy of the present invention may, after rapid solidification, be processed into a desired shape by extrusion, compression, press-forming or sintering under the processing conditions selected properly so that the objects of the present invention will not be impaired.
  • the alloying elements When a liquid alloy having one of the compositions described above is rapidly solidified, the alloying elements will dissolve in the a-AI matrix to form a supersaturated solid solution, and impart remarkably high corrosion resistance and strength to the matrix. Additionally, all other phases that will result from the addition of the alloying elements have high corrosion resistance and strength, thereby producing an aluminum alloy that exhibits very high corrosion resistance and strength features.
  • the conventionally processed AI-5 at.% Si alloy was comprised of an ⁇ -Al phase and a eutectoid of a-Al and cubic Si.
  • the amount of the cubic Si in the eutectoid was reduced to about one third of the amount in the conventionally processed counterpart and the resulting ⁇ -Al phase had at least 3 at% of Si dissolved therein.
  • the structure of the rapidly solidified alloy was uniform and comprised of fine grains not larger than 0.5 ⁇ m in size.
  • the rapidly solidified AI-5 at% Si alloy sample processed in accordance with the present ' invention had a pitting corrosion potential 175 mV higher than that of conventionally processed 99.999% pure aluminum, and 75 mV higher than that of the conventionally processed AI- 5 at.% Si alloy sample.
  • the alloy of the present invention had a very high hardness that contributed to its high strength property.
  • the Al-Ti-Si alloys were composed of three phases, i.e., ⁇ -Al, Al 3 Ti, and a eutectoid consisting of ⁇ -Al and cubic Si, and rapid solidification reduced the amount of the Al 2 Ti phase to about one fifth and the cubic Si in the eutectoid to about one third as a result of dissolution of substantial amounts of Ti and Si in the ⁇ -Al phase.
  • the ⁇ -Al phase in the Al-6% Ti-5% Si alloy sample prepared by rapid solidification in accordance with the present invention contained about 5 at% of Ti and about 3 at% of Si.
  • Each of the alloys prepared by the present invention had a uniform structure comprising fine grains no larger than 0.5 m. Their pitting potentials in deaerated 0.5N NaCl solution and Vickers hardness were measured. The results are shown in Table 3 for comparison with the data for conventionally processed samples.
  • the AI-Ti alloy and the Al-Ti-Si alloys rapidly solidified in accordance with the present invention contained sufficiently large amounts of Ti and Si in the ⁇ -Al phase to provide a highly protective passive film that could prevent the pitting corrosion by passivity breakdown. Therefore, the rapidly quenched alloys of the present invention had the pitting potentials 150 -250 mV higher than that of the 99.999% pure aluminum processed conventionally.
  • the alloys of the present invention were also characterized by fine grained phases containing the finely dispersed very hard Al 3 Ti phase and the ⁇ Al matrix supersaturated with alloying elements. As a result, the hardness of the alloys was even higher than the maximum value attainable by the conventional aluminum alloys.
  • Al-6 at% Zr Al-6 at% Zr
  • AI-2 at% Zr-5 at% Si Al- 4 at% Zr-5 at% Si
  • AI-6 at% Zr-5 at% Si were prepared by rapid solidification in accordance with the present invention using the rotating wheel method.
  • Each of the rapidly solidified samples had a fine-grained structure comprising particles no larger than 0.5 ⁇ m.
  • An Al-Zr-Si alloy processed conventionally was composed of three phases, i.e., ⁇ -Al, a eutectoid consisting of ⁇ -Al and cubic Si, and Al 0.45 Zr 0.33 Si 0.22 .
  • the Al-Zr-Si alloys solidified rapidly in accordance with the present invention were comprised of the ⁇ -A1 phase, Al 3 Zr phase and a eutectoid consisting of ⁇ -Al and cubic Si, with a smaller content of the Si in the eutectoid than in the conventionally processed counterparts.
  • the high-melting point Al 3 Zr phase precipitated before dissolving Si and then the eutectoid and ⁇ -Al phases rapidly formed. Therefore, the ⁇ -Al phase was supersaturated with Si and Zr.
  • the alloy samples prepared in accordance with the present invention were subjected to the measurements of the pitting potential in deaerated 0.5N NaCl solution and Vickers hardness. The results are shown in Table 4 for comparison with the data for samples solidified conventionally.
  • the alloys of the present invention formed a highly protective passive film over the a-AI phase that could prevent the pitting corrosion resulting from the passivity breakdown of the ⁇ -Al phase. Therefore, the rapidly quenched alloys of the present invention had the pitting potentials 160 -220 mV higher than the value for the 99.999% pure aluminum processed conventionally. In addi- ion to this feature of high corrosion resistance, the alloys had a significantly improved hardness because of the dispersion of the fine-grained Al 3 Zr phase.
  • Two molten samples of aluminum alloy viz., AI-2 at% Nb-5 at% Si and Al-6 at% Nb- 5 at% Si, were solidified by rapid quenching by means of the rotating wheel method.
  • Each of the solidified samples had a fine-grained structure comprising particles no larger than 0. 5 um.
  • An Al-Nb-Si alloy processed conventionally was composed of three phases, i.e., ⁇ -Al, Al 3 Nb and a eutectoid consisting of ⁇ -Al and cubic Si.
  • the AI,Nb phase having high corrosion resistance and hardness was dispersed as a fine-grained structure, -and the solutes formed supersaturated solid solutions of the ⁇ -Al phase. Therefore, the alloys had significantly high pitting potentials and improved hardness.
  • the aluminum alloys prepared by rapid solidification in accordance with the present invention had the pitting potentials 50 -330 mV higher than the value for the 99.999% pure aluminum solidified conventionally, and they also exhibited very high hardness levels.
  • the aluminum alloys prepared by rapid solidification in accordance with the present invention are characterized in that the elements added in order to enhance the corrosion resistance and strength are dissolved supersaturatedly in the ⁇ -Al phase, and form the eutectoid and intermetallic compounds having high corrosion resistance and high mechanical strength. Because of these features, the alloys of the present invention are possessed of the high degree of corrosion resistance and strength that has been unattainable with the prior art techniques.
  • the rapid quenching necessary for producing the alloys of the present invention can be realized by any of the methods that are well established in the art for rapid quenching from the liquid state. Therefore, the alloys of the present invention can be produced without using any special apparatus and, hence, will find great utility in practical applications.

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  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Materials Engineering (AREA)
  • Mechanical Engineering (AREA)
  • Metallurgy (AREA)
  • Organic Chemistry (AREA)
  • Continuous Casting (AREA)
  • Manufacture And Refinement Of Metals (AREA)
  • Resistance Heating (AREA)
EP86103164A 1985-03-11 1986-03-10 Aluminiumlegierungen mit hoher Korrosionsbeständigkeit und hoher Festigkeit Withdrawn EP0195341A1 (de)

Applications Claiming Priority (4)

Application Number Priority Date Filing Date Title
JP60046497A JPS61207541A (ja) 1985-03-11 1985-03-11 高耐食高強度アルミニウム合金
JP46497/85 1985-03-11
JP174091/85 1985-08-09
JP60174091A JPS6237335A (ja) 1985-08-09 1985-08-09 高耐食高強度アルミニウム合金

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EP0195341A1 true EP0195341A1 (de) 1986-09-24

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EP86103164A Withdrawn EP0195341A1 (de) 1985-03-11 1986-03-10 Aluminiumlegierungen mit hoher Korrosionsbeständigkeit und hoher Festigkeit

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EP (1) EP0195341A1 (de)
KR (1) KR900006612B1 (de)
AU (1) AU582834B2 (de)
BR (1) BR8601251A (de)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0445684A1 (de) * 1990-03-06 1991-09-11 Ykk Corporation Hochfeste, warmfeste Legierungen auf Aluminiumbasis
EP0819778A2 (de) * 1996-07-18 1998-01-21 Ykk Corporation Hochfeste Aluminiumlegierung
CN102343433A (zh) * 2011-09-21 2012-02-08 镇江忆诺唯记忆合金有限公司 一种铝铜合金定向凝固参数温度梯度t0和凝固速率v0的确定
WO2012110788A3 (en) * 2011-02-18 2012-10-26 Brunel University Method of refining metal alloys

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4347076A (en) * 1980-10-03 1982-08-31 Marko Materials, Inc. Aluminum-transition metal alloys made using rapidly solidified powers and method
EP0100287A1 (de) * 1982-07-06 1984-02-08 CNRS, Centre National de la Recherche Scientifique Amorphe oder mikrokristalline Legierungen auf Aluminiumbasis
EP0170963A2 (de) * 1984-08-10 1986-02-12 AlliedSignal Inc. Durch rasche Erstarrung hergestellte Legierungen aus Aluminium-Übergangsmetall-Silicium

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4347076A (en) * 1980-10-03 1982-08-31 Marko Materials, Inc. Aluminum-transition metal alloys made using rapidly solidified powers and method
EP0100287A1 (de) * 1982-07-06 1984-02-08 CNRS, Centre National de la Recherche Scientifique Amorphe oder mikrokristalline Legierungen auf Aluminiumbasis
EP0170963A2 (de) * 1984-08-10 1986-02-12 AlliedSignal Inc. Durch rasche Erstarrung hergestellte Legierungen aus Aluminium-Übergangsmetall-Silicium

Non-Patent Citations (9)

* Cited by examiner, † Cited by third party
Title
CHEMICAL ABSTRACTS, vol. 102, no. 14, 8th April 1985, page 271, no. 117802d, Columbus, Ohio, US; I. YAMAUCHI et al.: "Production and structure of rapidly solidified aluminum-silicon alloy powder by rotating-water-atomization process", & NIPPON KINZOKU GAKKAISHI 1985, 49(1), 72-7 *
CHEMICAL ABSTRACTS, vol. 102, no. 14, 8th April 1985, page 277, no. 117895m, Columbus, Ohio, US; R.D. FIELD et al.: "Precipitates possessing icosahedral symmetry in a rapidly solidified aluminum-manganese alloy", & MATER. SCI. ENG. 1985, 68(2), L17-L21 *
CHEMICAL ABSTRACTS, vol. 102, no. 14, 8th April 1985, page 278, no. 117905q, Columbus, Ohio, US; K.F- KOBAYASHI et al.: "Rapid solidification of aluminum-silicon alloys by the single-roll method", & NIPPON KINZOKU GAKKAISHI 1985, 49(1), 59-63 *
CHEMICAL ABSTRACTS, vol. 102, no. 8, 25th February 1985, page 239, no. 65937e, Columbus, Ohio, US; V.Y. PROKHOVSKII et al.: "Eutectic structure in a rapidly solidified aluminum-1.62 at. % manganese alloy", & FIZ. MET. METALLOVED. 1984, 58(5), 1026-9 *
CHEMICAL ABSTRACTS, vol. 96, no. 18, 3rd May 1982, page 315, no. 147603q, Columbus, Ohio, US; H.G. PARIS et al.: "The influence of particulate morphology and the thermal history in consolidation and metal working on mechanical properties of aluminum-iron-nickel-cobalt and aluminum-manganese-silicon alloys", & RAPID SOLIDIF. PROCESS.: PRINC. TECHNOL., PROC. INT. CONF., 2nd 1980, 331-41 *
CHEMICAL ABSTRACTS, vol. 96, no. 24, 14th June 1982, page 259, no. 203721r, Columbus, Ohio, US; M.C. FLEMINGS: "Segregation and structure in rapidly solidified cast metals", & METALL. TREATISES 1981, 291-300 *
CHEMICAL ABSTRACTS, vol. 98, no. 10, 7th March 1983, page 250, no. 76647k, Columbus, Ohio, US; I. PONTIKAKOS et al:: "Coarsening of intermetallic particles in rapidly solidified aluminum-transition metal alloys", & MET. SCI. 1982, 16(1), 27-30 *
CHEMICAL ABSTRACTS, vol. 99, no. 10, 5th September 1983, page 263, no. 75202v, Columbus, Ohio, US; S. HORI et al.: "Structure of rapidly solidified aluminum-zirconium alloys and its thermal stability", & PROC. INT. CONF. RAPIDLY QUENCHED MET., 4th 1981 (Pub. 1982), 2, 1545-8 *
CHEMICAL ABSTRACTS, vol. 99, no. 12, 19th September 1983, page 248, no. 92167e, Columbus, Ohio, US; S. HORI et al.: "Rapidly solidified structure and grain refinement of aluminum containing titanium", & KEIKINZOKU 1982, 32(11), 596-603 *

Cited By (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0445684A1 (de) * 1990-03-06 1991-09-11 Ykk Corporation Hochfeste, warmfeste Legierungen auf Aluminiumbasis
EP0819778A2 (de) * 1996-07-18 1998-01-21 Ykk Corporation Hochfeste Aluminiumlegierung
EP0819778A3 (de) * 1996-07-18 1998-02-11 Ykk Corporation Hochfeste Aluminiumlegierung
US6056802A (en) * 1996-07-18 2000-05-02 Ykk Corporation High-strength aluminum-based alloy
WO2012110788A3 (en) * 2011-02-18 2012-10-26 Brunel University Method of refining metal alloys
CN103370429A (zh) * 2011-02-18 2013-10-23 布鲁内尔大学 细化金属合金的方法
CN103370429B (zh) * 2011-02-18 2016-11-23 布鲁内尔大学 细化金属合金的方法
US10329651B2 (en) 2011-02-18 2019-06-25 Brunel University London Method of refining metal alloys
CN102343433A (zh) * 2011-09-21 2012-02-08 镇江忆诺唯记忆合金有限公司 一种铝铜合金定向凝固参数温度梯度t0和凝固速率v0的确定

Also Published As

Publication number Publication date
AU5436086A (en) 1986-09-18
KR900006612B1 (ko) 1990-09-13
KR870002289A (ko) 1987-03-30
BR8601251A (pt) 1986-12-02
AU582834B2 (en) 1989-04-13

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