Prediction modeling of surface roughness in milling of carbon fiber reinforced polymers (CFRP)

Owing to the advantages like high specific strength, high heat resistance and excellent wear resistance, carbon fiber reinforced polymers (CFRP) are used widely in the aerospace field. Nevertheless, due to shortcomings such as anisotropy and uneven phase distribution, the cutting failure behavior of CFRP includes a series of complex processes like fiber delamination and matrix fracture, which are thus classified as difficult-to-machine materials. In this study, the models for predicting relationships of cutting force with process parameters and with surface roughness are created by model analysis, in order to explore the effects of process parameters (cutting speed, feed rate and cutting depth) on the cutting force and surface roughness. As the results show, the cutting depth has the greatest influence on the cutting force, and an interaction is present among the process parameters regarding their effects on the magnitude of cutting force. Moreover, the effects of cutting forces in three directions on the roughness are also significantly interactive. Regarding the prediction models, the use of cutting force yields more accurate and stable prediction of roughness than the direct use of process parameters.