Copper alloy containing tin, method for producing same, and use of same

Abstract

The invention relates to a high-strength as-cast copper alloy containing tin, with excellent hot-workability and cold-workability properties, high resistance to abrasive wear, adhesive wear and fretting wear, and improved corrosion resistance and stress relaxation resistance, consisting (in wt. %) of: 4.0 to 23.0% Sn, 0.05 to 2.0% Si, 0.01 to 1.0% Al, 0.005 to 0.6% B, 0.001 to 0.08% P, optionally up to a maximum of 2.0% Zn, optionally up to a maximum of 0.6% Fe, optionally up to a maximum of 0.5% Mg, optionally up to a maximum of 0.25% Pb, with the remainder being copper and inevitable impurities, characterised in that the ratio of Si/B of the element content of the elements silicon and boron lies between 0.3 and 10. The invention also relates to a casting variant and a further-processed variant of the tin-containing copper alloy, a production method, and the use of the alloy.

1 . A high-strength tin-containing copper alloy having excellent hot formability and cold formability, high resistance to abrasive wear, adhesive wear and fretting wear and improved corrosion resistance and stress relaxation resistance, consisting of (in % by weight):
 4.0% to 23.0% Sn,   0.05% to 2.0% Si,   0.01% to 1.0% Al,   0.005% to 0.6% B,   0.001% to 0.08% P,   with or without up to a maximum of 2.0% Zn,   with or without up to a maximum of 0.6% Fe,   with or without up to a maximum of 0.5% Mg,   with or without up to a maximum of 0.25% Pb,   the balance being copper and unavoidable impurities, characterized in that
 the Si/B ratio of the element contents of the elements silicon and boron is between 0.3 and 10. 
   
     
     
         2 . A high-strength tin-containing copper alloy having excellent hot formability and cold formability, high resistance to abrasive wear, adhesive wear and fretting wear and improved corrosion resistance and stress relaxation resistance, consisting of (in % by weight):
 4.0% to 23.0% Sn,   0.05% to 2.0% Si,   0.01% to 1.0% Al,   0.005% to 0.6% B,   0.001% to 0.08% P,   with or without up to a maximum of 2.0% Zn,   with or without up to a maximum of 0.6% Fe,   with or without up to a maximum of 0.5% Mg,   with or without up to a maximum of 0.25% Pb,   the balance being copper and unavoidable impurities, characterized in that
 the Si/B ratio of the element contents of the elements silicon and boron is between 0.3 and 10; 
 after casting, the following microstructure constituents are present in the alloy: 
 a) 1% up to 98% by volume of Sn-rich δ phase ( 1 ), 
 b) 1% up to 20% by volume of Al- and B-containing phases, Si-containing and B-containing phases and/or addition compounds and/or mixed compounds composed of the two phases ( 2 ), 
 c) balance: solid solution of copper, consisting of low-tin α phase ( 3 ), wherein the Al-containing and B-containing phases, Si-containing and B-containing phases and/or addition compounds and/or mixed compounds composed of the two phases ( 2 ) are ensheathed by tin and/or the Sn-rich δ phase ( 1 ); 
 in the casting, the Al-containing and B-containing phases, Si-containing and B-containing phases and/or addition compounds and/or mixed compounds composed of the two phases ( 2 ) which are in the form of aluminum borides and silicon borides and/or in the form of addition compounds and/or mixed compounds of the aluminum borides and silicon borides constitute seeds for homogeneous crystallization during the solidification/cooling of the melt, such that the Sn-rich δ phase ( 1 ) is distributed homogeneously in the microstructure in the form of islands and/or a network; 
 the Al-containing and B-containing phases, Si-containing and B-containing phases and/or addition compounds and/or mixed compounds composed of the two phases ( 2 ) which are in the form of boron silicates and/or boron phosphorus silicates and/or aluminum oxide boron silicates and/or aluminum oxide boron phosphorus silicates, together with the phosphorus silicates and aluminum oxides, assume the role of a wear-protective and/or corrosion-protective coating on the semifinished products and components of the alloy. 
   
     
     
         3 . A high-strength tin-containing copper alloy having excellent hot formability and cold formability, high resistance to abrasive wear, adhesive wear and fretting wear and improved corrosion resistance and stress relaxation resistance, consisting of (in % by weight):
 4.0% to 23.0% Sn,   0.05% to 2.0% Si,   0.01% to 1.0% Al,   0.005% to 0.6% B,   0.001% to 0.08% P,   with or without up to a maximum of 2.0% Zn,   with or without up to a maximum of 0.6% Fe,   with or without up to a maximum of 0.5% Mg,   with or without up to a maximum of 0.25% Pb,   the balance being copper and unavoidable impurities, characterized in that
 the Si/B ratio of the element contents of the elements silicon and boron is between 0.3 and 10; 
 after the further processing of the alloy by at least one annealing operation or by at least one hot forming operation and/or cold forming operation in addition to at least one annealing operation, the following microstructure constituents are present in the alloy: 
 a) up to 75% by volume of Sn-rich δ phase ( 1 ), 
 b) 1% up to 25% by volume of Al-containing and B-containing phases, Si-containing and B-containing phases and/or addition compounds and/or mixed compounds composed of the two phases ( 2 ), 
 c) balance: solid solution of copper, consisting of low-tin α phase ( 3 ), wherein the Al-containing and B-containing phases, Si-containing and B-containing phases and/or addition compounds and/or mixed compounds composed of the two phases ( 2 ) are ensheathed by tin and/or the Sn-rich δ phase ( 1 ); 
 the Al-containing and B-containing phases, Si-containing and B-containing phases and/or addition compounds and/or mixed compounds composed of the two phases ( 2 ) present, which are in the form of aluminum borides and silicon borides and/or in the form of addition compounds and/or mixed compounds of the aluminum borides and silicon borides, constitute seeds for static and dynamic recrystallization of the microstructure during the further processing of the alloy, which enables the establishment of a homogeneous and fine-grain microstructure; 
 the Al-containing and B-containing phases, Si-containing and B-containing phases and/or addition compounds and/or mixed compounds composed of the two phases ( 2 ) which are in the form of boron silicates and/or boron phosphorus silicates and/or aluminum oxide boron silicates and/or aluminum oxide boron phosphorus silicates, together with the phosphorus silicates and aluminum oxides, assume the role of a wear-protective and/or corrosion-protective coating on the semifinished products and components of the alloy. 
   
     
     
         4 . The tin-containing copper alloy as claimed in  claim 1 , characterized in that the element silicon is present at from 0.05% to 1.5%. 
     
     
         5 . The tin-containing copper alloy as claimed in  claim 1 , characterized in that the element silicon is present at from 0.5% to 1.5%. 
     
     
         6 . The tin-containing copper alloy as claimed in  claim 1 , characterized in that the element aluminum is present at from 0.1% to 0.8%. 
     
     
         7 . The tin-containing copper alloy as claimed in  claim 1 , characterized in that the element boron is present at from 0.01% to 0.6%. 
     
     
         8 . The tin-containing copper alloy as claimed in  claim 1 , characterized in that the element phosphorus is present at from 0.001% to 0.05%. 
     
     
         9 . The tin-containing copper alloy as claimed in  claim 1 , characterized in that the alloy is free of lead aside from any unavoidable impurities. 
     
     
         10 . A process for producing end products and components having near-end-product form from a tin-containing copper alloy as claimed in  claim 1  with the aid of the sandcasting process, the shell mold casting process, precision casting process, full mold casting process, pressure diecasting process or lost foam process. 
     
     
         11 . A process for producing strips, sheets, plates, bolts, round wires, profile wires, round bars, profile bars, hollow bars, pipes and profiles from a tin-containing copper alloy as claimed in  claim 1  with the aid of the permanent mold casting process or the continuous or semicontinuous strand casting process. 
     
     
         12 . The process as claimed in  claim 11 , characterized in that the further processing of the cast state comprises the performance of at least one hot forming operation within the temperature range from 600 to 880° C. 
     
     
         13 . The process as claimed in  claim 10 , characterized in that at least one annealing treatment is conducted within the temperature range from 200 to 880° C. with the duration of 10 minutes to 6 hours. 
     
     
         14 . The process as claimed in  claim 11 , characterized in that the further processing of the cast state or of the hot-formed state or of the annealed cast state or of the annealed hot-formed state comprises the performance of at least one cold forming operation. 
     
     
         15 . The process as claimed in  claim 14 , characterized in that at least one annealing treatment is conducted within the temperature range from 200 to 880° C. with the duration of 10 minutes to 6 hours. 
     
     
         16 . The process as claimed in  claim 14 , characterized in that a stress relief annealing/age annealing operation is conducted within the temperature range from 200 to 650° C. with the duration of 0.5 to 6 hours. 
     
     
         17 . The use of the tin-containing copper alloy as claimed in  claim 1  for adjustment gibs and sliding gibs, for friction rings and friction disks, for slide bearing faces in composite components, for sliding elements and guide elements in internal combustion engines, valves, turbochargers, gears, exhaust gas aftertreatment systems, lever systems, braking systems and joint systems, hydraulic aggregates, or in machines and installations in mechanical engineering in general. 
     
     
         18 . The use of the tin-containing copper alloy as claimed in  claim 1  for components, wire elements, guiding elements and connection elements in electronics/electrical engineering. 
     
     
         19 . The use of the tin-containing copper alloy as claimed in  claim 1  for metallic articles in the breeding of seawater-dwelling organisms, for percussion instruments, for propellers, wings, marine propellers and hubs for shipbuilding, for housings of water pumps, oil pumps and fuel pumps, for guide wheels, runner wheels and paddle wheels for pumps and water turbines, for gears, worm gears, helical gears and for forcing nuts and spindle nuts, and for pipes, seals and connection bolts in the maritime and chemical industry.