SiC

f

/SiC composites have high hardness

high brittleness

wear resistance and are difficult to machine. During the cutting process

severe tool wear results in poor and unstable machining quality

which seriously restricts the rapid engineering application of SiC

f

/SiC composites. In this study

ultrasonic vibration-assisted milling and grinding experim

ents of SiC

f

/SiC composites were carried out. The surface roughness under different cooling methods was compared

and the combined cooling method of through-spindle coolant + external cooling was selected. The process parameters were optimized to obtain the suitable parameters for ultrasonic vibration-assisted milling and grinding of SiC

f

/SiC composites

providing a technical basis for the engineering application of such materials. The results show that the combined cooling method of through-spindle coolant and external cooling can provide more comprehensive and effective cooling effect. With the increase of spindle speed

the cutting force and machined surface roughness of SiC

f

/SiC composites generally show a decreasing trend. The increase of feed rate and cutting depth leads to the gradual increase of cutting force and surface roughness. Within the test range

there is an optimal interval of ultrasonic frequency for the machining effect; either too low (20 kHz) or too high (50 kHz) frequency will degrade the machining performance. To achieve good machined surface quality

the optimized combination of process parameters is: Spindle speed 14000 r/min

feed rate 50 mm/min

cutting depth 0.05 mm

ultrasonic frequency 40 kHz

ultrasonic amplitude 2 μm.