Copper-tin multicomponent bronze containing hard phases, production process and use

Abstract

The invention relates to a copper-tin multicomponent bronze consisting of (in % by weight): 0.5 to 14.0% Sn, 0.01 to 8.0% Zn, 0.01 to 0.8% Cr, 0.05 to 2.0% Al, 0.01 to 2.0% Si, optionally in addition up to a maximum of 0.1 to 3.0% Mn and optionally in addition up to a maximum of 0.08% P and optionally in addition up to a maximum of 0.08% S, remainder copper and unavoidable impurities, wherein, in the structure, silicides and/or chromium particles are deposited, which are surrounded by a tin film in the form of a highly tin-containing accumulation. A further aspect of the invention relates to a process for producing strips, plates, bolts, wires, rods, tubes and profiles of the copper-tin multicomponent bronze according to the invention, and also to a use.

1 . Copper-tin multicomponent bronze consisting of (in % by weight):
 0.5 to 14.0% Sn,   0.01 to 8.0% Zn,   0.01 to 0.8% Cr,   0.05 to 2.0% Al,   0.01 to 2.0% Si,   optionally in addition up to a maximum of 0.1 to 3.0% Mn and   optionally in addition up to a maximum of 0.08% P and   optionally in addition up to a maximum of 0.08% S,   remainder copper and unavoidable impurities,   wherein, in the structure, silicides and/or chromium particles are deposited, which are surrounded by a tin film in the form of a highly tin-containing accumulation.   
     
     
         2 . Copper-tin multicomponent bronze according to  claim 1 , characterized by:
 4.0 to 12.0% Sn,   2.0 to 7.0% Zn,   0.1 to 0.6% Cr,   0.2 to 1.3% Al,   0.1 to 0.6% Si,   optionally in addition up to a maximum of 0.08% P and   optionally in addition up to a maximum of 0.08% S,   remainder copper and unavoidable impurities.   
     
     
         3 . Copper-tin multicomponent bronze according to  claim 2 , characterized by:
 4.0 to 8.0% Sn,   2.0 to 4.0% Zn,   0.1 to 0.5% Cr,   0.1 to 0.8% Al,   0.1 to 0.5% Si,   optionally in addition up to a maximum of 0.08% P and   optionally in addition up to a maximum of 0.08% S,   remainder copper and unavoidable impurities.   
     
     
         4 . Copper-tin multicomponent bronze according to  claim 1 , characterized by:
 2.0 to 10.0% Sn,   1.0 to 7.0% Zn,   0.1 to 0.6 9 6 Cr,   0.3 to 2.5% Mn,   0.2 to 1.8% Al,   0.1 to 1.5% Si,   optionally in addition up to a maximum of 0.08% P and   optionally in addition up to a maximum of 0.08% S,   remainder copper and unavoidable impurities.   
     
     
         5 . Copper-tin multicomponent bronze according to  claim 4 , characterized by:
 2.0 to 6.0% Sn,   1.5 to 4.0% Zn,   0.1 to 0.5% Cr,   0.3 to 2.0% Mn,   0.2 to 1.3% Al,   0.1 to 1.3% Si,   optionally in addition up to a maximum of 0.08% P and   optionally in addition up to a maximum of 0.08% S,   remainder copper and unavoidable impurities.   
     
     
         6 . Copper-tin multicomponent bronze according to  claim 1 , characterized in that the matrix of the structure in the as-cast condition, with increasing Sn content of the alloy, consists of increasing proportions of δ phase (Sn-rich) in otherwise α phase (Sn-poor) of the zinc-containing Cu—Sn mixed crystal types. 
     
     
         7 . Copper-tin multicomponent bronze according to  claim 1 , characterized in that Cr silicides, Al-containing Cr silicides and Cr particles are incorporated into the matrix of the as-cast condition. 
     
     
         8 . Copper-tin multicomponent bronze according to  claim 4 , characterized in that Cr silicides, Al-containing Cr silicides, Mn-containing Cr mixed silicides, Mn—Al-containing Cr mixed silicides, Mn silicides, Al-containing Mn silicides and Cr particles are incorporated into the matrix of the as-cast condition. 
     
     
         9 . Copper-tin multicomponent bronze according to  claim 1 , characterized in that, after a further processing which comprises at least one hotforming or at least one coldforming or at least one hotforming and a coldforming and also optionally further annealing steps, the structure is present having a content of the δ phase up to 60% by volume, of the silicides and the Cr particles up to 20% by volume, and also a remainder α phase. 
     
     
         10 . Process for producing strips, plates, bolts, wires, rods, tubes and profiles of a copper-tin multicomponent bronze according to  claim 1  using the diecasting process or the continuous or semicontinuous extrusion casting process. 
     
     
         11 . Process according to  claim 10 , characterized in that the further processing of the as-cast condition comprises carrying out at least one hotforming in the temperature range from 600 to 880° C. 
     
     
         12 . Process according to  claim 10 , characterized in that at least one annealing treatment is carried out in a temperature range from 200 to 880° C. 
     
     
         13 . Process according to  claim 10 , characterized in that the further processing of the as-cast condition or of the hot-formed condition or of the annealed as-cast condition or of the annealed hot-formed condition comprises carrying out at least one coldforming. 
     
     
         14 . Process according to  claim 13 , characterized in that at least one annealing treatment is carried out in a temperature range from 400 to 850° C. 
     
     
         15 . Process according to  claim 13 , characterized in that a stress-relief annealing/ageing annealing is carried out in a temperature range from 200 to 650° C. 
     
     
         16 . Use of the copper-tin multicomponent bronze according to  claim 1  for sliding-bearing surfaces in composite components, for slide elements in internal combustion engines, gears, exhaust gas after-treatment systems, lever and joint systems, hydraulic units or in machines and systems of general mechanical engineering. 
     
     
         17 . Use of the copper-tin multicomponent bronze according to  claim 1  for construction elements in electronics/electrical engineering. 
     
     
         18 . Use of the copper-tin multicomponent bronze according to  claim 1  for metallic articles in the culture of organisms living in seawater.