Measurement of Pre-Self-Balanced Surface Residual Stresses Induced by Milling in Titanium Alloys and the FEM Validation

Flank milling was used to machine the titanium alloy workpiece, and high residual stresses were induced by milling in the superficial layers. The stress layers were corroded gradually and the changes of workpiece's bending deflection were measured. The stress values in the upper layers were calculated out based on the values in the bottom layers and the changes of the bending deflection. At last, the stress values got by this method are prior to the self-balanced state, so the result rules out the influence from the size and shape of the workpiece. The deformations of workpieces with different sizes and shapes can be predicted accurately based on these stress values. The correctness of this method has been verified by Finite Element Method (FEM).