Classifications

• • 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
• • 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
  • C22C21/06—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
  • 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 invention relates to a component made of an alloy of the AlMgSi type, with a high absorption capacity for kinetic energy by plastic deformation.
• Crash behavior is an increasingly important aspect in vehicle construction. This applies to road traffic as well as to rail traffic.
• the mechanical properties of the materials and joining zones used are of crucial importance.
• the aim is to absorb as much energy as possible before breaking. This can be achieved by a low ratio of yield strength to strength.
• An important material characteristic is also a high elongation.
• Joining zones, such as the weld seam, should differ as little as possible from the base material in their mechanical properties. In the case of extruded profiles, good elongation in the transverse direction is also of great importance.
• alloys of this type have good conditions for energy-absorbing parts in relation to other alloy systems such as AlZnMg in terms of their elongation and formability, a further optimization of the properties is desirable.
• the alloy AA6005A currently used in wagon construction brings with it a number of problems in production which are related to the tendency to recrystallize grainy. With a coarse grain structure, it is difficult to comply with the prescribed bending radii, which increases the tendency to form grain boundary openings during welding. This leads to a high number of nonconformities in production. If this is to be avoided, production must take place in such a way that the profile cross section predominantly has a fiber structure. This is currently only possible with an alloy composition that leads to higher press forces and significantly lower press speeds. However, this means that large losses in productivity have to be accepted.
• the object of the invention is therefore to provide a material with particularly good deformability and good mechanical properties of the component.
• the material should have a strength level comparable to or lower than that of the AA6005A alloy, but should ensure higher manufacturing reliability and higher productivity. Afford.
• the alloy according to the invention is considerably less sensitive to quenching in terms of strength and elongation than the alloy AA6005A, and even with wall thicknesses of 6 mm, a fine grain still occurs continuously.
• the alloy is therefore basically suitable for use with large profiles.
• the content limits for silicon and magnesium in% by weight are preferably determined as follows:
• alloy composition according to the invention for the production of components with high energy absorption capacity leads to a favorable microstructure of the component structure.
• the smallest possible grain size to improve the deformation properties is achieved with the alloy composition according to the invention.
• a component with particularly good properties with regard to energy absorption with good strength values can be achieved by a special heat treatment. This consists in the generation of an aged or partially hardened state of the alloy, i.e. the alloy is not hardened to maximum strength.
• the aged condition is produced by annealing in the range between 120 and 170 ° C, the annealing time being in the range between 4 and 16 h.
• the desired degree of aging can be determined on the basis of a simple series of experiments, the state T64 being preferred.
• Another preferred heat treatment is achieved by annealing between 190 and 230 ° C. for an annealing period of 1 to 5 hours. With this heat treatment, a slight aging is produced, with state T72 being preferred.
• the components according to the invention are extruded profiles.
• components are also conceivable which, starting from an extruded profile as a preform, are finished by hydroforming.
• the component can also be a forged part.
• a preferred use of the component according to the invention is seen as a safety part in vehicle construction.
• the mechanical properties of the alloys used according to the invention were determined in the tensile test and on the basis of fatigue tests for the heat treatment states T6 (Full curing) and T64 (partial curing) determined.
• This condition is set by aging at 160 ° C for 10 h.
• the heat treatment time is still below the hardness maximum, which is reached at about 20 h at 160 ° C.
• the characteristic values of the tensile test can vary depending on the precise analysis, degree of deformation, profile thickness and cooling conditions. The following minimum values have been established based on previous experience:
• the typical values of the yield strength are around 240 MPa, those of the strength in the base material lengthways around 290 MPa, the elongations A5 around 12%. In the transverse direction, the yield point and strength are approximately the same. A5 drops to 6%.
• press seams due to profile and sample shape were included. In no case was a break found in the immediate vicinity of the press seam, which is due to the particularly fine grain in the press seam area due to the high degree of deformation.
• the hardness is in the range from 94 to 105 HB.
• the characteristics of the welded joint apply to MIG machine welds. In the specified thickness range, the characteristic values differ when using SG-AlMg4, 5Mn-, SG- AlMg5 and SG-AlSi5 filler materials only a little. Errors, such as edge misalignment, which can be attributed to the problems when welding large profiles, have a greater influence on the results.
• the typical values of the welded joint processed are 130 MPa for RpO.2, 210 MPa for Rm and 4% for A100. These are achieved in an inspection approximately 30 days after welding. Cold curing in the heat affected zone is not yet complete after this time. In a test after about 90 days, a further increase in RpO.2 by about 10 MPa is found, while the strength increases only slightly and the elongation remains constant within the scope of the measurement accuracy.
• the value for the base material was determined on sections 3 mm thick. Under comparable conditions, values of ⁇ 100 MPa are generally achieved for AA6005A. The weld joint values were determined on 4 mm thick samples.
• the typical values of the strength in the basic material are 255 MPa, the elongations A5 by 22%. In the transverse direction, the strength drops slightly to 250 MPa. A5 drops to 12%. Press seams are included in all tested transverse samples. In no case was a break in the immediate vicinity of the press seam detected. The hardness is in the range from 74 to 85 HB.
• the typical values of the welded joint processed are 130 MPa for RpO.2, 210 MPa for Rm and 10% for A100. Such a high elongation is exceptional. This has a very favorable effect in the event of a crash. Here, too, higher values for RpO.2 are reached after about 90 days of storage at room temperature.
• Position 1 lies entirely in the weld metal, position 5 in the unaffected basic material.
• Base material (lengthways) 95 Butt joint (MIG) 85 45 with seam reinforcement 95 50 without night reinforcement
• the behavior in the event of a crash essentially depends on the material properties, on the shape and dimension of the crash element used.
• a first prerequisite for the suitability of a material in a specific shape and dimension is folding without premature breakage. Sections of pipes or of hollow profiles of rectangular cross-section which are compressed are used to test the crash behavior. Alloys A, B and C were compared in a first series of experiments, and alloys B, D and E in a second series of experiments with the compositions below.
• the alloy C used according to the invention always achieved the highest values of the absorbed energy in relation to the mass of the crash element. With this alloy, even in the T64 and T6 states, folding with a thin tube was achieved without breakage and higher energy absorption than in the T4 state.
• the alloys D and E used according to the invention always achieved the highest values of the absorbed energy in relation to the mass of the crash element.
• condition T72 was achieved with a heat treatment of 5 hours at 205 ° C.
• condition T6 by annealing for 10 hours at 160 ° C.
• the alloy recrystallizes fine-grained during pressing, with a remnant of a deformation structure remaining in the grains. This is the most important basis for the properties which are better in many aspects compared to the alloy AA6005A.
• the fine-grained recrystallization requires a sufficient degree of deformation in relation to time.
• the alloy according to the invention is easy to weld. In the case of butt joints from profile sections which have been worked out from large profiles and welded with SG-AlMg4.5Mn filler material, significant grain boundary openings have never been observed with wall thicknesses of up to 6 mm. corrosion
• the alloy according to the invention is well suited for use in vehicle construction.
• the characteristic values of the tensile test required for the base material and the welded joint are reliably achieved.
• the alloy can be used for small and large profiles in the same way. It is equally suitable for crash elements and for components that are produced by hydroforming.
• the production reliability is considerably better than that of the AA6005A alloy.
• the pressing speed can generally be increased by more than 50% compared to AA6005A.
• the partially hardened T64 variant in particular is characterized by a slight drop in the characteristics of the welded connection compared to the base material.
• the alloy according to the invention has proven to be an alloy with a good combination of properties of strength, elongation, weldability and production reliability. This applies to both the partially cured and fully cured condition.

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• Chemical & Material Sciences (AREA)
• Organic Chemistry (AREA)
• Mechanical Engineering (AREA)
• Metallurgy (AREA)
• Engineering & Computer Science (AREA)
• Materials Engineering (AREA)
• Physics & Mathematics (AREA)
• Thermal Sciences (AREA)
• Crystallography & Structural Chemistry (AREA)
• Body Structure For Vehicles (AREA)
• Transition And Organic Metals Composition Catalysts For Addition Polymerization (AREA)
• Glass Compositions (AREA)
• Conductive Materials (AREA)
• Extrusion Of Metal (AREA)
• Superconductors And Manufacturing Methods Therefor (AREA)
• Laminated Bodies (AREA)

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• 1996
  • 1996-05-22 EP EP96810325A patent/EP0808911A1/fr not_active Withdrawn
• 1997
  • 1997-05-16 WO PCT/CH1997/000193 patent/WO1997044501A1/fr not_active Ceased
  • 1997-05-16 AT AT97920475T patent/ATE205261T1/de not_active IP Right Cessation
  • 1997-05-16 DE DE59704542T patent/DE59704542D1/de not_active Expired - Lifetime
  • 1997-05-16 ES ES97920475T patent/ES2162285T3/es not_active Expired - Lifetime
  • 1997-05-16 EP EP97920475A patent/EP0902842B2/fr not_active Expired - Lifetime
  • 1997-05-16 AU AU26881/97A patent/AU2688197A/en not_active Abandoned
  • 1997-05-16 US US09/194,294 patent/US6685782B1/en not_active Expired - Lifetime
  • 1997-05-19 ZA ZA9704318A patent/ZA974318B/xx unknown

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