Effect Of Heat Treatment Process On Microstructure And Properties Of Cu-Ni-Sn Alloy

The Cu-Ni-Sn alloy material is a kind of copper alloy material with strong mechanical and corrosion properties.After the Sn atoms are completely dissolved in the Cu-Ni-Sn solid solution,phase transitions such as spinodal decomposition,orderly transition,and discontinuous precipitation occur during the aging period,which can have a great influence on the mechanical properties of alloy materials.As an alternative to early bronze,it has received special attention as a wear-resistant material in recent years.In this paper,we focus on the preparation of Cu-Ni-Sn alloy based on conventional melt-casting method.A series of processes,such as metallographic microscopy,transmission electron microscopy and differential thermal scanning analysis,are used.and mechanical properties of Cu-Ni-Sn metallographic microscope observation alloy are studied.The microstructure of the Cu-Ni-Sn alloy in the casting state,uniform deactivation state and thermal compression state were studied.The results showed that as-cast structure of Cu-Ni-Sn alloy is developed dendritic structure.There are serious dendritic segregation in the alloy.There are not many bony structures between dendrites.The transition layer between dendrites and bony structures is layered.,there was not much osseous tissue between the dendritic and dendritic structures,and the transition layer between the dendritic and osseous tissues was layered.The internal phase of the uniformly annealed Cu-Ni-Sn alloy is distributed in a layered form whose thickness is 150 nm or so.The nanophase particles are uniformly distributed in the layered phase between the matrix.The thermal extrusion alloy is a typical recrystallization structure in which the recrystallized grains of the Cu-Ni-Sn alloy after thermal extrusion are irregular and unevenly distributed in size,and a small amount of Honeycomb structure is precipitated between the inside of the grain and the grain.The rod-shaped phase is precipitated in the alloy.This paper analyzes of the different heat treatment processes on the structure and mechanical properties of homogeneous annealed Cu-Ni-Sn alloys thoroughly and comprehensively.The results show on the microstructure and that for the Cu-Ni-Sn alloy with uniform annealing,the 800/1h solid solution is sufficient to completely dissolve the second phase of the alloy,and the 340/3h aging alloy has the best comprehensive mechanical properties and tensile strength.722 MPa,The yield strength is 640 MPa and the elongation is 9.4%.The effects of different heat treatment processes on the microstructure and mechanical properties of hot extrusion Cu-Ni-Sn alloy were studied.The results show that 840/1h solid treatment can obtain the best solid treatment effect for hot extrusion Cu-Ni-Sn alloy.The tensile strength,yield strength and elongation of the aging alloy were 802.6MPa,472.5MPa and 22.92%,respectively.