Classifications

• • C—CHEMISTRY; METALLURGY
  • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
  • C22C—ALLOYS
  • C22C9/00—Alloys based on copper
  • C22C9/04—Alloys based on copper with zinc as the next major constituent
• • 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
  • C22F1/08—Changing the physical structure of non-ferrous metals or alloys by heat treatment or by hot or cold working of copper or alloys based thereon

Definitions

• the invention relates to an electrical clamp containing a copper-zinc alloy according to the preamble of claim 1.
• CN103589903A discloses the tubes made of a copper alloy, consisting of (in% by weight): 63.0-66.0% Cu, 0.6-1.2% Al, ⁇ 0.7% Ni, 1.6-2.4% Mn, ⁇ 0.5% Fe, 0.8-1.3% Si , ⁇ 0.1% Pb and balance Cu.
• bronze materials are used, which are characterized by a fine microstructure with a grain size of maximum 3 ⁇ m.
• significantly high mechanical strengths are achieved with greatly improved forming properties.
• processors can achieve correspondingly tight bending radii.
• the improved flexibility also means that the roughness in the forming zones is significantly less than when using standard bronze. Subsequent coatings with a lower layer thickness can thus be carried out, which can result in considerable cost savings in further processing.
• the electrical conductivity is identical to that of standard bronzes and is approximately 7.5 to 12 MS / m.
• Another precipitation-hardening CuNi1CoSi alloy with Ni-Co mixed silicides is also very suitable for economical miniaturization of connectors.
• the material is high-strength, has a comparatively good electrical and thermal conductivity at 29 MS / m and is easy to process.
• the materials described are particularly suitable for processing on punching / bending machines and can only be machined with great effort.
• CuPb1P is another easily machinable machine material that also has a high electrical conductivity of around 50 MS / m. It is particularly suitable for connectors and other electronic applications.
• the range of alloys is rounded off by further precipitation hardening materials.
• These include, for example, CuNi1Pb1P and CuNiPb0.5P as a low-alloy copper material with high strength, good conductivity of at least 32 MS / m and good machinability.
• the Pb component makes the material particularly suitable for machined plug contacts in electrical engineering and electronics.
• the invention has for its object to develop an electrical clamp from a low-lead or lead-free copper alloy.
• iron-nickel-manganese-containing mixed silicides are embedded in the matrix.
• the structure consists of an ⁇ matrix, which contains deposits of 5 to 45% by volume of the ⁇ phase and mixed silicides containing iron-nickel-manganese of up to 20% by volume.
• the structure contains the iron-nickel-manganese-containing mixed silicides with a stem-like form and iron-nickel-enriched mixed silicides with a globular shape.
• alloy composition according to the invention is suitable for electrical terminals. So far, such alloys have been used in accordance with the German published patent application DE 10 2007 029 991 A1 the applicant is only intended for use for sliding elements in internal combustion engines, transmissions or hydraulic units.
• the invention is based on the consideration of providing an electrical clamp with a copper-zinc alloy with embedded iron-nickel-manganese-containing mixed silicides, which can be produced in particular with the aid of the continuous or semi-continuous continuous casting process. Due to the mixed silicide formation and microstructure formation, the copper-zinc alloy has a very high electrical conductivity for this group of materials.
• the alloy also has high hardness and strength values, nevertheless a necessary degree of ductility, expressed by the elongation at break during a tensile test, is guaranteed.
• the subject of the invention proves to be particularly suitable for electrical terminals, optionally also with screw connections.
• iron and nickel-rich mixed silicides are first separated out. With further growth, these precipitates can grow into mixed silicides containing iron-nickel-manganese of considerable size, often in the form of stalks. Furthermore, a considerable proportion remains rather small with a globular shape, which is finely distributed in the matrix. The finely divided silicides are seen as the reason that the ⁇ phase is stabilizing.
• the alloy has a high ductility during cold forming. In the case of electrical clamps, this is particularly important in crimping, in which the material is usually subjected to severe plastic deformation. This enables the material to be flanged, squeezed or folded with almost any degree of deformation, without the formation of cracks in the material.
• the material is also particularly suitable for machined electrical terminals.
• the good machinability is already achieved with a beta phase of 5% by volume. Up to 45 vol.% Of the ⁇ -phase, the chip formation during the machining process also improves at higher contents, by desirably forming short chips. With a ⁇ -phase content of less than 5% by volume, machinability is no longer satisfactory when used as an automatic material for high machining rates. With a ⁇ -phase content of over 45% by volume, it can be seen that the toughness of the material and the temperature resistance of the structure deteriorate. The final state of the alloy from the respective manufacturing process leads to a ⁇ phase, which is embedded in an island structure in an ⁇ matrix. Such ⁇ -phase islands are particularly favorable for the machinability and the corrosion resistance of the alloy.
• the particular advantage of the alloy according to the invention is thus based on a combination of properties optimized for the intended use in the form of an increase in the strength, the temperature resistance of the structure and the electrical conductivity with sufficient toughness properties at the same time.
• the material solution claimed takes into account the need for an environmentally friendly lead-free alloy alternative due to the lead content substituted for conventional alloys.
• this material is predestined for special applications where, despite high demands on hardness and strength, a necessary degree of plasticizability is required.
• the final relaxation annealing is preferably carried out at 300 ° C. to 400 ° C. for 3 to 4 hours.
• the copper-zinc alloy can contain 33.5 to 36.0% Zn. With these higher zinc contents, the toughness properties and good electrical conductivity required for electrical clamps can still be achieved.
• the proportion of further elements, in particular the copper proportion, is correspondingly reduced by the highest possible zinc content. With the consequence that the alloy results in a correspondingly lower metal price due to a higher proportion of cheaper zinc.
• the electrical conductivity of the alloy can advantageously be at least 5.8 MS / m. Particularly preferred conductivities are at least 10 MS / m to over 13 MS / m. These values are not achieved by comparable materials, such as the brass containing lead. Even values above 13 MS / m can be set by suitable further processing steps.
• the structure consisting of an ⁇ matrix, which contains deposits of 5 to 45% by volume in the ⁇ phase and mixed silicides containing iron-nickel-manganese up to 20% by volume after further processing, which includes at least one hot forming and / or cold forming and optionally further annealing steps.
• this alloy ensures an advantageous temperature resistance of the structure with sufficient toughness properties for the manufacture of the electrical clamp.
• the relationship between the level and distribution of the proportion of the ⁇ phase and the temperature resistance of the structure is the relationship between the level and distribution of the proportion of the ⁇ phase and the temperature resistance of the structure.
• this cubic, body-centered type of crystal has an indispensable strength-increasing function in the copper-zinc alloys, the minimization of the ⁇ content should not be the only focus.
• the structure of the copper-zinc alloy can be modified in such a way that, in addition to high strength, it also has sufficient temperature resistance, ductility and good electrical conductivity.
• At least one relaxation annealing in a temperature range from 250 to 450 ° C. and preferably an annealing time of 2 to 5 hours can follow in the further processing after the shaping.
• Cast bolts of the copper-zinc alloy according to the invention were produced by continuous casting or permanent mold casting.
• the chemical composition of the continuous casting of alloy 1 and the die casting of alloys 2 and 3 is shown in Table 1.
• Table 1 Chemical composition of the casting bolts or casting blocks (in% by weight) without indication of possible impurities Cu [%] Zn [%] Si [%] Mn [%] Ni [%] Sn [%] Al [%] Fe [%] Leg. 1 64.0 31.1 1.0 2.0 0.6 ⁇ 0.01 0.9 0.4 Leg. 2 64.0 30.8 1.1 2.1 0.6 - 0.9 0.5 Leg. 3 61.6 34.8 0.7 1.7 0.3 - 0.5 0.4
• Table 2 Structure parameters, electrical conductivity and mechanical properties at two positions of the pipes in the final state (Leg. 1) ⁇ content [%] Grain size [ ⁇ m] Electrical conductivity [MS / m] Rm [MPa] R p0.2 [MPa] Elongation at break A5 [%] Hardness HB 5 15-20 11.4 640 560 14.5 201 15-20 20-25 11.2 647 572 13.2 199
• Table 3 Structure parameters, electrical conductivity and mechanical properties of the round bars in the final state (Leg. 1) Round rod ⁇ [mm] ⁇ content [%] Grain size [ ⁇ m] Electrical conductivity [MS / m] R m [MPa] R p0.2 [MPa] Elongation at break A5 [%] Hardness HB 13.40 5 20-25 11.4 607 512 12.4 191 16.35 15-20 25 10.9 638 549 12.0 199 45.50 10-15 25 10.7 570 420 20.1 172
• the characteristic value for the electrical conductivity can be further increased for the formats of alloys 2 and 3 produced according to production sequence 5 by an additional stress relief annealing carried out at a temperature of 250 to 450 ° C.
• the ⁇ content is between 5-20% in all 5 production sequences. Further investigations show that the ⁇ contents are preferably between 5-30%.
• the island-like formation of the ⁇ phase in the final state of production, embedded in a structure of an ⁇ matrix, can appear in somewhat different forms. With increasingly lower contents of the ⁇ -phase, islands that are isolated from each other appear, which in the limit case can form a kind of gusset filling compared to the crystallites of the ⁇ -matrix.

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• 2014
  • 2014-09-25 DE DE102014014239.6A patent/DE102014014239B4/de active Active
• 2015
  • 2015-08-17 TW TW104126718A patent/TWI651422B/zh active
  • 2015-08-29 WO PCT/EP2015/001759 patent/WO2016045770A1/de active Application Filing
  • 2015-08-29 US US15/326,788 patent/US20170204501A1/en not_active Abandoned
  • 2015-08-29 EP EP15756842.9A patent/EP3198048B1/de active Active
  • 2015-08-29 CN CN201580045155.XA patent/CN106715731A/zh active Pending
  • 2015-08-29 PL PL15756842T patent/PL3198048T3/pl unknown
  • 2015-08-29 JP JP2017504661A patent/JP6514318B2/ja active Active
  • 2015-08-29 KR KR1020177001287A patent/KR20170059436A/ko not_active Application Discontinuation

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