Research On The Forming And Microstructure Evolution During Cross Wedge Rolling Of TC4 Alloy Shaft

With the progress and development of industrial science and technology,the problem of equipment lightweight is becoming increasingly prominent,especially in the fields of aerospace,Marine science and military manufacturing.TC4 titanium alloy is one of the best materials to achieve lightweight equipment,and the most common parts in many equipment are shaft parts.In this paper,the near-net forming technology of TC4 titanium alloy shaft was studied,and the processing of TC4 titanium alloy shaft by cross wedge rolling forming technology was utilized to effectively avoid many prominent problems such as complex procedures,low production efficiency and low material utilization rate encountered by traditional machining methods.Based on the deform-3D simulation software,the macroscopic and microscopic test simulation of TC4 titanium alloy shaft was carried out,and the research method of the combination of cross wedge rolling experiment and metallographic experiment was carried out.Main research contents of this paper:(1)Study on the forming mechanism of rolled parts in TC4 titanium alloy cross wedge rolling process.Based on deform-3D finite element simulation software,the change of TC4 titanium alloy shaft wedge rolling process was simulated,the flow velocity,the distribution of stress and strain and the changing trend of temperature field of metal in different rolling stages are analyzed.(2)Study on the influence of rolling parameters on the surface forming quality of TC4 titanium alloy shaft.Explain the forming mechanism of TC4 titanium alloy cross wedge rolling,on the basis of three levels orthogonal test design of five factors,explore the rolling process parameters on the axial influence regulation of the neck,to optimize the process parameters,and application data statistical analysis software SPSS25.0,fitting the parameters of rolling(independent variables)and shaft neck(dependent variable)of the linear regression equation.At last,the rolling quality control law is obtained by cross wedge rolling test.(3)Study influence of die parameters and rolling process parameters on microstructure evolution of TC4 titanium alloy shaft.Based on the microstructure constitutive model,dynamic recrystallization model and dislocation model of TC4 titanium alloy,the finite element model of TC4 titanium alloy wedge rolling was established,and the influence of mold parameters and process parameters on the grain shape,grain size,dynamic recrystallization volume fraction and grain distribution uniformity of the rolled part was investigated.The microstructure evolution law of TC4 titanium alloy shaft was obtained by comparison of simulation and metallographic experiment.(4)Mechanical properties of TC4 titanium alloy shaft rolled by cross wedge rolling.The mechanical properties of the rolled TC4 titanium alloy shaft were measured by microhardness test and tensile test.The influence law of process parameters on mechanical properties of rolled parts is analyzed,which provides theoretical basis for practical engineering application.