【摘要】 SiC_f/SiC复合材料硬度高、脆性大、耐磨损、难加工，切削过程中刀具磨损严重，加工质量差且不稳定，严重制约了SiC_f/SiC复合材料快速工程化应用。本研究通过开展SiC_f/SiC复合材料超声振动辅助铣磨试验，对比不同冷却方式下的表面粗糙度，选择中心出水+外部冷却的组合冷却方式，并对工艺参数进行优化，优选出适用于SiC_f/SiC复合材料超声振动辅助铣磨加工的工艺参数，为该类材料的工程化应用提供技术支撑。结果表明，中心出水+外部冷却的组合冷却方式能够提供更全面、更有效的冷却效果。随着主轴转速的增加，SiC_f/SiC复合材料切削力和加工表面粗糙度总体呈现减小的趋势；进给速度和切削深度的增大会导致切削力和表面粗糙度逐渐增大；在测试范围内，超声频率存在最佳区间，频率过低（20 kHz）或过高（50 kHz）均会导致加工效果变差。为了获得良好的加工表面质量，工艺参数优化组合为：主轴转速14000 r/min、进给速度50 mm/min、切削深度0.05 mm、超声频率40kHz、超声振幅2??m。更多还原

【Abstract】 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 experiments 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.更多还原