Investigation of Cutting Force and the Material Removal Mechanism in the Ultrasonic Vibration-Assisted Scratching of 2D-SiCf/SiC Composites

Abstract

Ultrasonic-assisted grinding (UAG) is widely used in the manufacture of hard and brittle materials. However, the process removal mechanism was never elucidated and its potential is yet to be fully exploited. In this paper, the mechanism of material removal is analyzed by ultrasonic-assisted scratching. Three distinct surfaces (S1, S2, and S3) were selected on the basis of the braided and laminated structure of fiber bundles. The ultrasonic-assisted scratching experiment is carried out under different conditions, and the scratching force (SF) of the tested surface will fluctuate periodically. Under the conditions of different feed speeds, depths, and ultrasonic amplitudes, the normal scratching force (SFn) is greater than the tangential scratching force (SFt), and the average scratching force on the three surfaces is generally S3 > S2 >S1. Among the three processing parameters, the speed has the most significant influence on the scratching force, while the scratching depth has little influence on the scratching force. Under the same conditions and surface cutting mode, the ultrasonic vibration-assisted scratching force is slightly lower than the conventional scratching force. The scratching force decreases first and then increases with the amplitude of ultrasonic vibration. Because the fiber undergoes a brittle fracture in the ultrasonic-assisted scratching process, the matrix is torn, and the surface residues are discharged in time; therefore, the surface roughness is improved.

The Electrostatic Induction Characteristics of SiC/SiC Particles in Aero-Engine Exhaust Gases: A Simulated Experiment and Analysis

“…where A is the sensor area, and x is the distance between the charged particle and the sensor face. Equation (2) shows that the sensitivity to charge is directly proportional to the magnitude of the charge and the area of the sensor face, while it is inversely proportional to the distance between the charge and the sensor. The insulating properties of the conveying medium will impact the retention of charge on the moving particle.…”

“…Due to its high-temperature capability and excellent wear and corrosion resistance [1], silicon carbide-fiber-reinforced silicon carbide (SiC/SiC), a ceramic matrix composite (CMC) material, is regarded by the National Aeronautics and Space Administration (NASA) as the most promising material for the hot-section components of modern aero-engines [2,3] and has been successfully applied to aero-engine components such as turbofans [4], rotor blades [5], and combustion chambers [6]. These SiC/SiC hot-section components usually operate at elevated temperatures and high pressures and in intense mechanical strain environments, which readily predispose these components to mechanical issues, leading to a subsequent deterioration in performance.…”

Comparative Study on Micro-Grinding Performance of 2.5D Cf/SiCs, 2.5D SiCf/SiCs, and SiC Ceramics

“…breakage, fiber pullout, and fiber exposure. Lin et al [21] analyzed the mechanism of material removal in ultrasonic-vibration-assisted scratching of 2D SiCf/SiC composites. In the ultrasonic-assisted scratching process, the surface roughness is improved because the fiber undergoes a bri le fracture, the matrix is torn, and the surface residues are discharged in time.…”

“…They pointed out that the dominant material removal mode of the SiC f /SiC composites was a brittle fracture, and the damage characteristics mainly included natural fiber fracture, matrix breakage, fiber pullout, and fiber exposure. Lin et al [21] analyzed the mechanism of material removal in ultrasonic-vibration-assisted scratching of 2D SiC f /SiC composites. In the ultrasonic-assisted scratching process, the surface roughness is improved because the fiber undergoes a brittle fracture, the matrix is torn, and the surface residues are discharged in time.…”