Comparing the Chatter Characteristic in Milling of Ti6Al4V Alloy with and without Laser Assistance

Laser-assisted machining (LAM) is a promising technique to enhance the machinability of difficult-to-cut materials. However, many challenges remain for its practical engineering application, despite extensive research on the material removal mechanism in LAM. One key challenge is to elucidate how the laser affects the machining dynamics (e.g. cutting forces and chatter characteristics) and machined qualities in realistic machining scenarios. Therefore, this study aims to investigate the relationship between chatter characteristics and laser assistance in milling processes. Two sets of milling experiments with different depths of cut were conducted on wedge-shaped Ti6Al4V alloys with and without laser assistance. The milling forces were measured and analyzed using Short-time Fourier transforms and Wavelet transforms to detect chatter in frequency and time-frequency domains. Moreover, four indicators (i.e., standard deviation, Kurtosis, fuzzy entropy, envelope entropy) were extracted to monitor the milling conditions. The results showed that dry milling experienced a transition from stable machining to slight chatter at an axial depth of cut (ADOC) of 1.75 µm and then to severe chatter at ADOC=4.63 µm under the same cutting parameters, while LAM only exhibited slight chatter at ADOC=4.00 µm, demonstrating the specific effect of laser assistance on suppressing chatter. This was further confirmed by the observed surface morphology and roughness.