INVESTIGATION ON SURFACE INTEGRITY IN AXIAL ULTRASONIC VIBRATION-ASSISTED MILLING IN-SITU TIB2/7050AL MMCS

The particle reinforced metal matrix composites (PRMMCs) are a new kind promising materials with attracting attentions due to its superior properties such as improved strength, low density, excellent low-temperature performance and increased wear resistance. However, it was a difficult-to-cut material due to the existence of hard ceramic particles. Ultrasonic vibration-assisted machining method has attracted many attentions in machining difficult-to-cut materials. In this study, an experimental investigation was conducted on the effect of cutting and vibration parameters on the machined surface integrity of ultrasonic vibration-assisted milling in-situ TiB2/7050Al metal matrix composites. After all experiments, surface integrity such as surface roughness, residual stress, hardness and machined defects and so on were comparatively analyzed between conventional and ultrasonic vibration-assisted cutting methods. It was found that the machined surface roughness of ultrasonic vibration-assisted milling was a little larger than that of conventional milling while the compressive residual stress of the former was greater than that of the latter. It could be found that it could obtain better machined performance when vibration frequency is 30 kHz and amplitude is 4 μm in the range of given experimental parameters.