In this study

a cutting force model was established for the side milling conditions of superalloy GH4169

which considered the instantaneous undeformed chip thickness and the real-time changes of the contact angle caused by the geometric characteristics of the workpiece profile and the tool wear during the cutting process. Then considering the effects of cutting force fluctuation and temperature accumulation on the microhardness

a prediction model for the microhardness of workpieces processed by side milling was established based on the dislocation density-based model. By carrying out experiments and comparing the experimental data

the accuracy of the modelis verified. Andit was found in the experiment that when the radius of curvature of the workpiece profile suddenly changed from infinity to about 5 mm

the peak value of cutting force significantly changed

the surface microhardness value and the depth of the hardened layer also increased. Finally

a three-factor and three-level orthogonal simulation is designed to explore the influence of processing parameters on microhardness.The results demonstrate that within the studied machining parameter range

the surface microhardness increases with the increase of the axial depth of cut

while the depth of the hardened layer decreases with the increase of the spindle speed and increases with the increase of the feed speed and the axial depth of cut.