锥度球头刀四轴铣削 TC4 残余应力梯度分布反解

The internal and external profilc finishing of the metal reinforcing edges of the leading edge of large composite fan blades for commercial acro-engincs was aecomplished by four-axis milling with a customized taper ball-end cutter, and the machining residual Stresses introduced at this stagc often caused excessive bending and torsional deformations leading to dimensional overshoots of the parts. For the four-axis milling of titanium alloy TC4 with taper ball-end cutter, an inverse identifica-tion method of milling residual stress gradient distribution was proposed based on the deformation tests of thin plate machining herein. The hyperbolic tangent models were used to parametrically char-acterize the milling residual stress gradient distribution, and the Solution of the residual stress gradient distribution was converted into the inverse Solution of two pending coefficients k and co. The modcl coefficient k was determined by testing the residual stress on the machined surfaces of the titanium alloy speeimen blocks, and the model coefficient co was inversely solved by testing the bending deformation deflection of milled titanium alloy thin plates, then the residual stress gradient distribution curve was determined. Four groups of titanium alloy TC4 test block milling Validation experiments were car-ried out, and the test results show that the average prediction aecuraey of the milling residual stress gradient distribution is as high as 99.35%. Compared with the traditional X-ray test method, the proposed method avoids the use of electrolytic corrosion Stripping to test the subsurface residual Stresses, and also takes into füll consideration the non-uniformity of the distribution of milling residual stresses on the machined surfaces, namely the problcm of the dispersion of milling residual stresses.