Study On Hot Deformation Behavior And Hot Extrusion Process Of Cu6Ni6Sn Alloy

Cu6Ni6Sn alloy is an ideal material for connecting rod bushing because of its characteristics of high strength,wear resistance,corrosion resistance and good thermal stability.Meanwhile,hot extrusion is an important processing method for manufacturing connecting rod bushing.However,the hot extrusion process is affected by a variety of factors,among which extrusion temperature,extrusion speed and extrusion ratio and other extrusion forming process parameters will affect the macroscopic deformation and microstructure changes of the extrusion products,thus determining the final product performance.Therefore,it is very important to master the thermal deformation behavior of Cu6Ni6Sn alloy under different deformation conditions to provide a reference for hot extrusion processing,and then optimize the technological parameters of hot extrusion,which is essential to improve the quality and performance of connecting rod bushing products.This paper mainly studies the hot deformation behavior and hot extrusion forming process of Cu6Ni6Sn alloy.The main contents include:(1)Using Gleeble-3800 thermal simulation machine for Cu6Ni6Sn alloy hot compression test,the true stress-true strain situation during the thermal deformation of this alloy was analyzed,and the thermal deformation behavior under different deformation conditions was investigated in conjunction with its microstructure.(2)The microstructure evolution of Cu6Ni6Sn alloy during thermal deformation was mastered.The kinetic model and the grain size model for Cu6Ni6Sn alloy were developed from the results of hot compression tests to provide predictions for this behavior of the alloy.(3)The finite element analysis of the hot extrusion process of Cu6Ni6Sn alloy cylindrical parts was carried out by having the software of DEFORM-3D.The dynamic recrystallization model was input in DEFORM-3D software for the the numerical simulation of the hot extrusion process,and the distribution patterns of macroscopic aspects such as strain field and temperature field,microscopic aspects such as dynamic recrystallization volume fraction and average grain size,and the influence of hot extrusion process parameters on them were obtained.(4)Hot extrusion process parameter optimization using Response Surface Method and experimental verification.Setting extrusion temperature,extrusion speed and extrusion ratio as optimization parameters,and average grain size and standard deviation of average grain size as optimization objectives,Design-Expert software was used to optimize extrusion parameters,and the optimal combination of parameters was obtained as extrusion temperature 776?,extrusion speed 0.5mm/s,and extrusion ratio 2.0.The effectiveness of numerical simulation and optimization results was verified by the the trial productions and microstructure tests of Cu6Ni6Sn alloy Cylindrical parts.