A gas-liquid-solid three-phase abrasive flow processing method based on bubble collapsing

Abstract

Soft abrasive flow (SAF) processing presents advantages in avoiding surface damages and adapting complex workpiece shapes. However, the current SAF method exhibits low processing efficiency for materials. To solve this problem, a gas-liquid-solid three-phase abrasive flow processing method (GLSP) based on bubble collapsing is proposed. Through a surface constrained module, a multi-inlet constrained flow passage for silicon wafer processing is constructed, in which the bubbles are injected into the abrasive flow to strengthen the processing efficiency. On the basis of the Euler multi-phase model and population balance model (PBM), a GLSP fluid mechanic model is set up. Simulation results show that the bubble collapse region can be controlled by designing the flow passage structure and that the near-wall particle turbulent motion can be strengthened by decreasing the fluid viscosity. The observation and processing experiments show that the most violent bubble collapsing occurs in the initial constrained surface region. Bubble collapsing can result in an average particle velocity increase from 12.90 to 15.97 m/s. The proposed GLSP method can increase the processing efficiency by 50% compared with the SAF method, and the average surface roughness can reach 2.84 nm.