Axial cutting force prediction model of titanium matrix composites TiBw/TC4 in ultrasonic vibration–assisted drilling

Ultrasonic vibration–assisted drilling (UVAD) can significantly improve the quality of the hole while reducing the axial force of drilling, which has important application prospects. In order to reveal the variation law of drilling force under the joint action of ultrasonic vibration and cutting heat, and to guide the optimization of high-efficiency UVAD process, titanium matrix composites TiBw/TC4 (TiB whisker volume fraction of 8.5%) is taken as the research object. Firstly, based on the theory of fracture indentation and the theory of ordinary drilling (OD), the comprehensive softening coefficient of the material under the action of ultrasonic impact and cutting temperature is introduced, and the model of axial drilling force considering the softening effect is established. Secondly, the experiment of UVAD was carried out, and the interaction mechanism about drilling force and vibration impact and drilling temperature was analyzed. Finally, the experimental data was used to establish the softening coefficient response surface, which described visually the variation law of the softening coefficient. The feasibility of the drilling force model was verified, and the trend between the drilling parameters and the drilling force was analyzed. The results show that the error between experimental axial drilling force value and prediction value of UVAD is less than 10%, and the maximum axial drilling force is about 23.1% lower than OD.