Debonding Fiber Damage Mechanism Modeling for Machining Damage Inhibition During Rotary Ultrasonic Face Grinding SiO_2f/SiO₂

The debonding fiber defects on the grinding surface of SiO_2f/SiO₂ ceramic matrix composites deteriorate the service performance of related components. The low-damage process window is the key information to suppress machining damage by controlling grinding parameters. A mechanism model for debonding fiber damage on SiO_2f/SiO₂ surface was first proposed in this paper by the large deformation analysis for SiO₂ fibers during rotary ultrasonic face grinding (RUFG). The established mechanism model built a bridge between grinding parameters and damage inhibition by integrating the ultrasonic stress effect, grinding force calculation, and critical fracture curvature cutting-off criterion of SiO₂ fibers. The modeling mechanism for fiber deformation and fracture in grinding was validated by in situ observation of single abrasive grit scratching experiments. Besides, the low debonding damage process window predicted by the model was verified by experimental results and could be adopted to suppress the debonding fiber damage in grinding. The affected mechanism of fiber orientation, ultrasonic amplitude, and fiber-matrix interface strength on the low debonding damage process window was analyzed based on the theoretical and experimental results. The damage inhibition effect of the RUFG process was limited by the low fiber-matrix interface strength and axial cutter-relieving movement component. The ultrasonic-assisted vibration exerted its auxiliary effects through the ultrasonic stress effect and force reduction effect. The prerequisite for exerting the damage inhibition effect of RUFG was that the fiber-matrix interface strength was sufficient to resist the negative influence of the ultrasonic stress effect.