Application of pre-stressed cutting to aviation alloy: The effect on residual stress and surface roughness

Abstract

The state of residual stress on the machined surface seriously affects its service performance and service life. Theoretically, pre-stressed technique is an efficient and convenient method to adjust the residual stress during the machining. In this paper, theoretical derivation, numerical simulation, and experiment are combined to study the influence of pre-stress on cutting ring parts. According to the principle of pre-stressed cutting, the elastic mechanics analysis and calculation of the pre-stressed load of ring parts are carried out. The relationship between applied pre-stress and radial deformation of the ring parts is set up. The maximum pre-stress that can be loaded is also deduced. Then, a two-dimensional finite element model (FEM) of pre-stressed cutting titanium alloy is established. Finally, a novel pre-stressed loading device for ring parts is developed to perform pre-stressed cutting experiment. The simulated cutting force, chip morphology, and residual stress are consistent with experimental data, which verify the validity of the FEM. Experimental results demonstrate that with the pre-stress increasing from 0 to 410 MPa, the cutting force does not change significantly. The serrated degree of the serrated chip fluctuates around 0.5. And the residual stress of the machined surface decreases sharply from 207 to −49 MPa. Further, a slight reduction in surface roughness and fewer defects on the surface morphology are observed.