Classifications

• • C—CHEMISTRY; METALLURGY
  • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
  • C22C—ALLOYS
  • C22C13/00—Alloys based on tin
  • C22C13/02—Alloys based on tin with antimony or bismuth as the next major constituent
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
  • F16C—SHAFTS; FLEXIBLE SHAFTS; ELEMENTS OR CRANKSHAFT MECHANISMS; ROTARY BODIES OTHER THAN GEARING ELEMENTS; BEARINGS
  • F16C33/00—Parts of bearings; Special methods for making bearings or parts thereof
  • F16C33/02—Parts of sliding-contact bearings
  • F16C33/04—Brasses; Bushes; Linings
  • F16C33/06—Sliding surface mainly made of metal
  • F16C33/12—Structural composition; Use of special materials or surface treatments, e.g. for rust-proofing
  • F16C33/121—Use of special materials

Definitions

• the invention relates to a tin-based white metal plain bearing alloy containing antimony as the main alloying element and 1 to 10% by weight of copper.
• Tin-based plain bearing alloys are known (GB 2 146 354 A) containing 2 to 15% by weight of antimony, 1 to 10% by weight of copper, up to 15% by weight of lead and further alloying elements such as cadmium, nickel, silver, tellurium , Cobalt, magnesium, manganese and arsenic, wherein a content of 0.005 to 0.5 wt.% Titanium refine the microstructure of the bearing material and thus improve the carrying capacity of a sliding bearing.
• the invention is therefore an object of the invention to increase the strength of a sliding bearing alloy of tin-based white metal of the type described without having to use polluting alloying elements such as cadmium, lead, arsenic and chromium.
• the cadmium-, lead-, arsenic- and chromium-free white metal apart from unavoidable impurities, contains 4 to 30% by weight of antimony as the main alloying element, at least one element consisting of a cobalt, manganese, scandium and germanium-containing element group a total concentration of between 0.2 and 2.6% by weight, based on the elements used in this group, and at least one element of a magnesium, nickel, zirconium and titanium-containing element group in a total concentration of between 0.05 and 10 based on the elements used in this group 1, 7 wt.%, Wherein the sum content of antimony and copper at a minimum of three times the copper content corresponding antimony content is at most 35 wt.%. In both cases, the minimum content is the efficacy limit, the maximum content prevents extensive, due to their size and number already harmful excretions.
• the alloying of cobalt, manganese, scandium and / or germanium advantageously achieves a refinement and a rounding off of the precipitated intermetallic phases.
• Germanium also forms intermetallic compounds with free copper, which positively influences the strength of the alloy, provided that the size of the individual precipitates is kept low. Due to the primary crystallization of these higher melting elements, solidification of the white metal results in the formation of a large number of crystallization nuclei which considerably reduce the precipitation of the intermetallic phases with copper and antimony, thereby increasing their strength The tin matrix can be significantly improved without significantly affecting the deformability of the white metal.
• the elements of the magnesium, nickel, zirconium and titanium-containing element group bind a part of the antimony in intermetallic phases, in particular at higher antimony contents, which counteracts an otherwise associated with a higher antimony content embrittlement.
• Magnesium also has a strong deoxidizing effect. Excessive levels of magnesium, however, increase the susceptibility to corrosion, especially the pitting occurs.
• Nickel is found in the copper-tin crystals and increases their hardness. However, it has no negative influence on the sliding properties of the alloy according to the invention. Nickel also improves corrosion resistance and reduces susceptibility to segregation. Contents above 5 wt.%, However, lead to embrittlement of the alloy due to the coating of large, hard phases.
• Additions of zirconium in the stated contents have a strengthening effect on the matrix and serve for grain refining. Additions of titanium aid grain refining, thereby improving the bearing capacity of the plain bearing alloy, but its hardness remains almost unchanged.
• An increased copper content solidifies the alloy because an intermetallic phase forms between antimony and copper. However, the copper content must not exceed the stated limit ratio because of the otherwise excessive formation of nadelfömiger copper-tin phases.
• the white metal can additionally 0.6 to 1, 8 wt.%, Preferably 0.7 to 0.9 wt. % Zinc can be added. Zinc serves to refine the copper-tin and tin antimony phases by forming additional nuclei. This prevents growth of these phases to a harmful size.
• Similar effects can be achieved by adding to the white metal at least one element from an elemental group comprising silver, gold, vanadium and iron, the individual parts of these alloying elements not exceeding 4% by weight.
• the total amount must be limited to the top with 8% by weight.
• the white metal may have an aluminum content of 0.05 to 2.5 wt.%.
• the aluminum content must be limited to the top in order not to have to negatively impact the porosity of the white metal.
• Silicon has a similar influence on the white metal. Excess silicon combines with zirconium and scandium to form intermetallic phases, preventing the formation of wave damaging primary silicon crystals. For this reason, silicon and aluminum are preferably added in hypoeutectic composition to avoid the formation of primary silicon crystals. It should therefore the aluminum and the silicon as a heterogeneous phase mixture are present, wherein the aluminum content corresponds to 7 to 45 times the silicon content.
• the white metal In order to increase the strength properties of the white metal by intermetallic compounds, it is also possible to alloy lithium in a proportion of 0.05 to 1.6% by weight.
• the addition of at least one rare earth metal may improve the casting properties of the white metal alloy and reduce the susceptibility to segregation.
• these rare earths have a grain-refining effect.
• the total concentration of the rare earths used may not exceed 1, 3 wt.%, If adverse effects are to be suppressed.
• a plain bearing alloy with 15.4 wt.% Antimony, 4.6 wt.% Copper, 0.3 wt.% Manganese, 0.07 wt.% Cobalt, 0.1 wt.% Magnesium, 0, 05 wt.% Nickel and 0.7 wt.% Zinc, remainder tin.
• This plain bearing alloy had a casting hardness of 36.1 HBW 2.5 / 15.625 / 15. Although the hardness fell off due to cold rolling, it could be increased again to 37.6 HBW 2.5 / 15.625 / 15 by a heat treatment, ie to a hardness above the casting hardness.

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• 2008
  • 2008-03-03 AT AT3442008A patent/AT505664B1/de not_active IP Right Cessation
• 2009
  • 2009-03-02 KR KR1020107016818A patent/KR101566044B1/ko not_active IP Right Cessation
  • 2009-03-02 JP JP2010549994A patent/JP5563489B2/ja not_active Expired - Fee Related
  • 2009-03-02 DE DE112009000194T patent/DE112009000194A5/de not_active Ceased
  • 2009-03-02 CN CN200980107224.XA patent/CN101960029B/zh not_active Expired - Fee Related
  • 2009-03-02 WO PCT/AT2009/000082 patent/WO2009108975A1/de active Application Filing

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