Effect Of Grain Size Effect On Deformation Behavior Of Pure Titanium Micro-stamping And Finite Element Simulation

As the demand for fine parts in various industries increases year by year,the production process and theoretical research in the field of small-sized parts processing are more important.During the micro-forming process,a deformation law different from the conventional macroscopic size caused by the change of the material size may occur,that is,the size effect.In this paper,the industrial pure titanium materials with different grain sizes of 0.05 mm were micro-stamped on the micro-punching machine.At the same time,finite element simulation analysis of micro-stamping process was carried out by ABAQUS software.The main research results are as follows:(1)As the annealing temperature increases,the grain size of the material increases.When the annealing temperature is 400 ° C and 500 ° C,the grain size is not much different.When the annealing temperature is 600 ° C,the grain size grows rapidly.As the grain size increases,the tensile strength and elongation of the material decrease.As the grain size increases,the fracture mechanism of the material changes from microporous polymerization fracture to cleavage fracture.(2)Micro-stamping test on industrial pure titanium TA1 material with thickness of 0.05 mm,when the grain size is 23?m,when the punching speed is 1mm/s,there is no obvious dark pit and surface distortion on the surface of the sample,and the wrinkle depth is shallow.Compared with stamping samples of other grain sizes and process conditions,better quality stamping samples can be obtained under this condition.(3)For the stamping conditions with grain size of 23?m and stamping speed of 1mm/s,homogeneous and heterogeneous finite element simulation analysis is carried out respectively.Compared with homogeneous finite element simulation results of pure titanium micro-stamping,Voronoi model is introduced.The heterogeneous finite element simulation results are more consistent with the actual experimental results.(4)Using the Voronoi model,the stamping process with a thickness of 0.02 mm was simulated.The simulation results showed that when the thickness was 0.02 mm,the grain size was 23 ?m,and the punching speed was 1 mm/s,the bottom of the stamped sample showed obvious cracking.