Study On Preparation Technology And Microalloying Modification Of Copper-tin Alloy

High-performance copper alloys are widely used in automobile manufacturing,shipbuilding,and seawater desalination systems due to their high strength,high hardness,and good corrosion resistance and wear resistance.The ultra-high solid solution copper-tin alloy studied in this subject is an important material for the production of superconducting material Nb₃Sn.Nb₃Sn is a superconducting material that is widely used in the frontiers of basic science and cutting-edge equipment.Current research shows that the solid solubility of Sn in copper-tin alloys needs to reach more than 14 wt.%.According to the Cu-Sn binary phase diagram,the solubility limit of Sn in Cu is only 13.5 wt.%.When the Sn content is greater than 13.5 wt.%,intermetallic compounds such as Cu3Sn,Cu3Sn5,etc.will appear in the alloy.With the increase of Sn content,the content of intermetallic compounds is getting higher and higher.Therefore,based on the current research,this subject adopts the method of adding alloying elements in copper-tin alloy to study its influence mechanism and determine the appropriate addition amount to achieve the purpose of improving alloy performance.On the other hand,through rolling deformation combined with electrical pulse treatment to study the structure and properties of copper-tin alloy,a high solid solubility,high performance copper-tin alloy preparation process was obtained.Research indicates:?1?The structure of the copper-tin alloy prepared by powder metallurgy is not uniform,and some Sn-rich phases are still segregated at the grain boundaries.The matrix is mainly composed of?-phase solid solution.In addition to the?phase,copper-tin alloys prepared with different Sn contents also generate some intermetallic compounds.When the sintering temperature increases at 650-750?,the solid solution of solute atoms in the copper-tin alloy increases with the increase of Sn content.The density,hardness,and electrical conductivity of the alloy also increase with the sintering temperature.?2?The rolling and electrical pulse treatment of the copper-tin alloy can effectively promote the dissolution of solute Sn atoms in the copper-tin alloy into the Cu matrix.The high-energy non-equilibrium grain boundaries generated during the deformation process provide the diffusion of Sn atoms powerful channels,combined with the thermal and non-thermal effects of electrical pulses,provide favorable conditions for Sn atom diffusion in thermodynamics and kinetics and promote the formation of solid solutions.In addition,under the action of electric pulses,it promotes the re-dissolution of intermetallic compounds,that is,both deformation and electric pulse treatment work together to promote Sn solid solution.?3?For copper-tin alloys with different Ti content,as the Ti content increases,the degree of refinement of the primary phase of copper-tin alloy by Ti is greater.A second phase will appear in the copper-tin alloy;the density and density of the alloy and the electrical conductivity will increase.The alloy solid solution increases with increasing Ti content.?4?The white precipitates on the surface of copper-tin alloys with different In contents are dispersed phase distribution,and the alloy surface has metallic luster.With the increase of In content,the alloy structure still only has?phase,and no second phase appears.With the increase of In addition,the density,density and electrical conductivity of the alloy have been significantly improved,and the solid solution increases with the increase of In content.