Surface characteristics investigation of ultrasonic longitudinal-torsional milling of high-volume fraction SiCp/Al

As an advanced aviation material, machining of high-volume fraction SiCp/Al material is a difficult problem caused by the existence of a large number of SiC particles, which has always been one of the key bottlenecks restricting the SiCp/Al material application in the aviation industry. Ultrasonic longitudinal-torsional milling (ULTM) combines the advantages of both ultrasonic longitudinal and torsional milling, enabling to produce a high material removal rate along with high surface quality. This paper dealed with the ULTM cutting edge trajectory, revealing the reason why the surface quality was improved by ULTM. Since machining parameters were closely related to the surface characteristics, the finite element simulation analysis of the SiC particle machining process was conducted to study the influence of different ultrasonic amplitudes on the surface characteristics of SiCp/Al material. A comparative experimental study was performed to verify the correctness of theory and simulation under ULTM and traditional milling. The results indicated that ULTM afforded obvious advantages in improving surface quality, due to the unique tool-workpiece separation characteristics. Moreover, the ultrasonic amplitude had a significant influence on the surface roughness, second only to cutting speed, followed by feed per tooth and cutting depth, which laid the foundation for the application of ULTM to improve the surface quality of SiCp/Al material.