Abstract:
The milling process of SiC
f/SiC composites is characterized by high cutting forces and challenging quality assurance, rendering them a typical difficult-to-machine material. In this study, multiple linear regression is adopted to establish predictive models for tangential force
Fx and radial force
Fy in both laser-assisted single-step milling and sequential milling (transition layer/ablation layer). The effects of spindle speed, feed per tooth, and laser power on milling forces are systematically investigated. Experimental validation demonstrates that the average relative error of each model remains below 5%, with coefficients of determination (
R2) exceeding 0.86. Integrating microscopic surface morphology analysis with strain-rate hardening theory and material removal mechanisms, the influence mechanisms of process parameters on milling forces are elucidated. The results reveal that
Fx increases with spindle speed owing to the strain-rate hardening effect; laser power exhibits a positive correlation with
Fx in LAAM(S T) due to the thermal insulation effect of the ablation layer and the phase-transformation gradient within the transition layer, whereas its influence is negligible in LAAM(O) and LAAM(S A). Due to the change of cutting mechanism from "indentation fracture" to "shear slip", the increase of feed rate in LAAM (O) ablation layer will increase the milling force due to the increase of removal volume of indentation fracture. The milling force of the transition layer and the loose powder layer of LAAM (S T) and LAAM (S A) decreases with the increase of feed rate due to the shear slip effect.