Finite Element Simulation Of TC4Titanium Alloy Shot Peening

Because of the high specific strength, good plasticity, toughness, corrosion resistance and biocompatibility, titanium alloys are widely applied in aviation, aerospace, vessel, petrochemical industry, biological health, etc. However, the premature invalidation of titanium alloy products resulted from the low hardness, poor wear resistance and fatigue resistant performance cause great economic loss in the industrial application. It is highly regarded that hardness, wear resistance and fatigue resistant of TC4can be effectively improved by shot peening. In this paper, effects of shot dimension, shot velocity and surface coverage in the shot peening simulation process on surface integrity were investigated by the finite element software ABAQUS. Meanwhile the experimental tests of TC4shot peening were carried out and studied. By the comparative analysis of the experimental results and simulation ones, the validity of the numerical simulation is verified and proven. The results show that:According to the FEM simulation analysis, the depths of maximum residual stress and residual stress field are very sensitive to the shot dimension. As the shot dimension increases, residual stress curves deviate to the right and the surface roughness of the plate increases. The residual stress curves move to the bottom right and four eigenvalues grow along with the increasing of shot velocity. The depth of residual stress field increases from92.2μm to167.3μm, with the increase of shot velocity from40m/s to100m/s. The faster the shot velocity, the more rough the surface. The surface roughness with the velocity of100m/s is23.8μm which is nearly twice as large as that with the velocity of40m/s. When the surface coverage is under200%, the depths of maximum residual stress and residual stress field vary in small scales of51.5-52.7μm and138-149μm, respectively. As the coverage goes up, the maximum residual stress and surface roughness increase with the surface residual stress decreasing.The simulation results with the shot velocity of80m/s agree with the experimental results with the shot peening intensity of0.2mmA except that experimental value of surface residual stress is higher than simulation one. And the experimental value of surface residual stress and the depth of residual stress field are755.8MPa and170μm, respectively. Simulation results of residual stress and surface roughness with different shot velocities have same changing trends as the experimental ones with different shot peening pressures. As the shot peening pressure or shot velocity increases, the experimental value of surface roughness or the simulation one increases almost linearly. Compared with the roughness of14.8μm with the shot peening pressure of0.15MPa, the roughness increases58.5%with shot peening pressure of0.3MPa. Meanwhile, the influences of simulation results of surface coverage on residual stress and roughness are consistent with the experimental ones.