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
• • C—CHEMISTRY; METALLURGY
  • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
  • C22C—ALLOYS
  • C22C21/00—Alloys based on aluminium
  • C22C21/06—Alloys based on aluminium with magnesium as the next major constituent
  • C22C21/08—Alloys based on aluminium with magnesium as the next major constituent with silicon
• • 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
• • 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
  • C22F1/05—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 of the Al-Si-Mg type, i.e. containing silicon and magnesium in approximately equal proportions

Definitions

• the present invention relates to an aluminum alloy for thin sheets suitable for obtaining lids and bodies of boxes intended to contain food or carbonated drinks and to a process for manufacturing said sheets.
• Aluminum alloys are now widely used for the manufacture of boxes intended to contain both solid and liquid food as well as carbonated drinks. These boxes are made up of two parts: a body with an integrated bottom, the side wall of which can be printed or not, on which is attached a cover provided with an easy opening system, in particular in the case of boxes for carbonated drinks.
• the covers are generally obtained by cutting a thin sheet of thickness between 200 and 400 ⁇ m and the bodies of neighboring thickness are either by stamping or by stamping followed by re-drawing.
• the sheet should have characteristics adapted to each of these peculiarities.
• the covers with easy opening must have a mechanical resistance higher than that of the other covers so as not to tear during their use;
• the printed or re-stretched bodies must have a relatively low rate of horns to avoid any deformation either of the preprinted characters or of the upper part of the body which receives the cover; bodies subjected to re-stretching should not seize on contact with the tooling to avoid the appearance of scratches or even breaks.
• lids and bodies have very different compositions in particular as regards their magnesium and manganese content. This requires different production lines to develop them and thus strike their cost price. But to these disadvantages is grafted the problem of recycling boxes after use: in fact, given the growing share taken by aluminum alloys on the box market, we realized the significant savings which would result if we recovered said boxes instead of putting them in the landfill. But, like the bodies, which are practically inseparable from the covers, an economic recycling involves the remelting of the whole box. Hence the obtaining of an alloy of intermediate composition between that of the body and the cover which must therefore be divided into two fractions, each of which is then returned to the title by adding pure aluminum and elements d alloys.
• the sheets obtained have the mechanical characteristics with respect to sheet metal for a body 0.2% elastic limit of 250 to 310 MPa, a tensile strength of 260 to 320 MPa and an elongation at break of 1 to 8%; for cover sheets, the values of these characteristics are 310-370 MPa, 320-380 MPa and 1 to 5% respectively.
• the applicant has aimed to increase these characteristics, in particular in the case of sheets for covers. It achieved this by moving towards an alloy more charged with silicon and characterized in that it contains by weight percent: 0.8 ⁇ manganese ⁇ 1.8, 1 ⁇ silicon ⁇ 2, 0.7 ⁇ magnesium ⁇ 3, iron ⁇ 0.5, copper ⁇ 0.5, chromium ⁇ 0.5, aluminum balance.
• the higher silicon content, in combination with magnesium, promotes the formation of Mg2Si which acts as a hardening agent.
• the presence of an amount of manganese on average greater than in the previous patent has the effect of greatly reducing the seizure phenomena during the re-stretching of the can bodies.
• the method consists in developing a melt of given composition and in pouring it into strips for example in a cylinder machine which, thanks to the high cooling rates, makes it possible to keep in solid solution a lot of Mg, Si and Mn, which then makes it easier to dissolve.
• the strip has a thickness of between 6 and 12 mm.
• the strip After casting, the strip is heated to between 500 and 620 ° C for 2 to 20 hours so as to homogenize the metal. Then, after cold rolling to an intermediate thickness, a solution treatment is carried out at a temperature between 500 and 600 ° C. for 0.5 to 10 minutes followed by air quenching allowing characteristics to be obtained superior to those of conventional alloys. Preferably, this dissolution is carried out between 530 and 580 ° C for 1 to 2 minutes. Then laminated to the final thickness and optionally reheats the sheet to 200-220 ° C for 5 to 15 minutes so as to cook the varnishes. It is possible to carry out an annealing of 30 min to 2 hours between 100 and 250 ° C. at a thickness intermediate between the thickness of dissolution - hardening and the final thickness.

Landscapes

• Chemical & Material Sciences (AREA)
• Organic Chemistry (AREA)
• Materials Engineering (AREA)
• Metallurgy (AREA)
• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Crystallography & Structural Chemistry (AREA)
• Thermal Sciences (AREA)
• Physics & Mathematics (AREA)
• Metal Rolling (AREA)
• Continuous Casting (AREA)
• Closures For Containers (AREA)
• Rigid Containers With Two Or More Constituent Elements (AREA)
• Shaping Metal By Deep-Drawing, Or The Like (AREA)
• Coating With Molten Metal (AREA)
• Other Surface Treatments For Metallic Materials (AREA)
• Adornments (AREA)
• Laminated Bodies (AREA)

Applications Claiming Priority (2)

Publications (2)

Family

ID=9351314

Family Applications (1)

Country Status (15)

Cited By (5)

Families Citing this family (16)

Citations (6)

Family Cites Families (4)

• 1987
  • 1987-05-19 FR FR8707170A patent/FR2615530B1/fr not_active Expired - Fee Related
• 1988
  • 1988-04-07 US US07/178,539 patent/US4855107A/en not_active Expired - Lifetime
  • 1988-05-14 CN CN88102846A patent/CN1009374B/zh not_active Expired
  • 1988-05-15 EG EG26788A patent/EG18835A/xx active
  • 1988-05-16 NO NO882130A patent/NO172136C/no unknown
  • 1988-05-16 NZ NZ224639A patent/NZ224639A/xx unknown
  • 1988-05-17 BR BR8802384A patent/BR8802384A/pt active Search and Examination
  • 1988-05-17 JP JP63120393A patent/JPS63317640A/ja active Granted
  • 1988-05-17 DE DE8888420161T patent/DE3865524D1/de not_active Expired - Fee Related
  • 1988-05-17 EP EP88420161A patent/EP0292411B1/de not_active Expired - Lifetime
  • 1988-05-18 KR KR1019880005769A patent/KR910006022B1/ko not_active IP Right Cessation
  • 1988-05-18 CA CA000567087A patent/CA1307141C/fr not_active Expired - Fee Related
  • 1988-05-18 MX MX011530A patent/MX169312B/es unknown
  • 1988-05-18 AU AU16391/88A patent/AU599546B2/en not_active Ceased
• 1991
  • 1991-10-17 GR GR91400444T patent/GR3002901T3/el unknown

Patent Citations (6)

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