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<p>Reaction-bonded silicon carbide (RB-SiC) ceramics are highly hard and brittle materials with an inherently heterogeneous microstructure comprising SiC matrix, free silicon, and interfacial phases. Conventional finite element models based on homogeneous material assumptions are inadequate for capturing the complex deformation and removal mechanisms in RB-SiC machining. This study develops a two-dimensional single-grit cutting model incorporating zero-thickness cohesive elements to explicitly represent the multiphase structure (SiC matrix, free silicon and phase boundary) of the RB-SiC workpiece, which is validated through nano-scratch tests. Subsequently, the model is employed to investigate material removal mechanisms and cutting force characteristics of RB-SiC ceramics in elliptical ultrasonic vibration-assisted cutting (EUVAC). Simulation results identify three primary material removal modes: friction-induced plastic deformation, pulverization via pore–crack interaction, and brittle fracture dominated by interfacial debonding and crack propagation-with brittle fracture being the predominant mechanism. Cracks initiate preferentially within the low-toughness SiC matrix and propagate along phase boundaries. Furthermore, cutting forces are effectively suppressed around 40&#xa0;kHz, with no substantial further reduction beyond this frequency. Increased cutting depth elevates cutting forces and accelerates the occurrence of peak forces due to enhanced material deformation resistance. Therefore, high-frequency and low-amplitude machining is recommended for RB-SiC ceramics. These findings provide a theoretical basis for high-quality processing of RB-SiC ceramics.</p>

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Material removal in ultrasonic vibration-assisted cutting of RB-SiC ceramics: a cohesive zone model approach

  • 期刊论文

  • 发表日期：

    2026年3月18日

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  • Zhiwen Jiang,
  • Dongju Chen,
  • Chao Gao,
  • Kun Sun,
  • Ri Pan,
  • Jinwei Fan

摘要

Reaction-bonded silicon carbide (RB-SiC) ceramics are highly hard and brittle materials with an inherently heterogeneous microstructure comprising SiC matrix, free silicon, and interfacial phases. Conventional finite element models based on homogeneous material assumptions are inadequate for capturing the complex deformation and removal mechanisms in RB-SiC machining. This study develops a two-dimensional single-grit cutting model incorporating zero-thickness cohesive elements to explicitly represent the multiphase structure (SiC matrix, free silicon and phase boundary) of the RB-SiC workpiece, which is validated through nano-scratch tests. Subsequently, the model is employed to investigate material removal mechanisms and cutting force characteristics of RB-SiC ceramics in elliptical ultrasonic vibration-assisted cutting (EUVAC). Simulation results identify three primary material removal modes: friction-induced plastic deformation, pulverization via pore–crack interaction, and brittle fracture dominated by interfacial debonding and crack propagation-with brittle fracture being the predominant mechanism. Cracks initiate preferentially within the low-toughness SiC matrix and propagate along phase boundaries. Furthermore, cutting forces are effectively suppressed around 40 kHz, with no substantial further reduction beyond this frequency. Increased cutting depth elevates cutting forces and accelerates the occurrence of peak forces due to enhanced material deformation resistance. Therefore, high-frequency and low-amplitude machining is recommended for RB-SiC ceramics. These findings provide a theoretical basis for high-quality processing of RB-SiC ceramics.