Cutting Force Model of SiCp/Al Composites in Ultrasonic Elliptical Vibration Assisted Cutting with Negative Rake Angle

SiCp/Al composites are widely used in many important engineering applications due to their excellent material properties. High-volume fraction SiCp/Al composites are recognised as a typical difficult-to-machining material with significant brittleness, and negative rake angles are more suitable for cutting brittle materials. Ultrasonic elliptical vibration cutting (UEVC) has proven to be a specialised machining method that can improve the machinability of difficult-to-machining materials. Elucidating the influence of the negative rake angle on the dynamic properties of composites during UEVC is therefore particularly important. In this paper, the direction of the combined cutting force is considered separately for negative rake angle tools, as well as UEVC's unique transient cutting thickness, variable cutting angle, transient shear angle and characteristic of friction reversal, a UEVC cutting force model based on negative tool rake angle has been developed. And the deviation of the main cutting force between the experimental value and the theoretical value is less than 15% by systematic turning experiments, which verifies the accuracy of the model. Finally, the influence of different machining parameters on the cutting force is determined using the established model. The results show its effect on the cutting force is more significant when the cutting speed is less than 200 mm/s, other things being equal. In addition, the cutting force tends to decrease significantly as the depth of cut from 5 μm to 20 μm increases. However, the cutting force fluctuated less when the feed was increased. This work provides the benchmark for negative rake angle cutting of SiCp/Al.