Surface finishing additive manufactured internal passages using dynamic cavitation-assisted microparticle flow is becoming popular. The nucleation, growth, and collapse of the cavitation inside complex passages are crucial contributors for surface finishing and call for understanding for process improvement. In this work, we aimed to surface finish linear Direct Metal Laser Sintered (DMLS) AlSi10Mg conformal cooling channels (CCC). First, we surface finished the cooling channels with a square cross-section of width varying from 5 mm to 1 mm and length extending up to 50 mm using various multiphase finishing modes. Second, we characterized the multiphase flow with a high-speed camera and underwater hydrophone measurements, focusing on the cavitation effects, inside the cooling channels. Third, we performed numerical simulations and extracted cavitation and turbulent kinetic energy distributions inside the channels. The surface texture results were supported by cavitation frequency (nf_o), root mean square pressure (P_rms), and acoustic energy (E_A) observations from the hydrophone. Finally, we explained the surface finishing trend by varying the channel size and length using numerical simulation results. The results suggest that the cavitation phase distribution decrease with a decrease in channel size and an increase in the channel length. The method proposed is useful in establishing appropriate process parameters to achieve a uniform surface finish along the entire channel length.

使用动态空化辅助微粒流的表面处理增材制造内部通道正变得流行。复杂通道内空化的成核、生长和坍塌是表面精加工的关键因素，需要了解工艺改进。在这项工作中，我们的目标是对线性直接金属激光烧结 (DMLS) AlSi10Mg 随形冷却通道 (CCC) 进行表面处理。首先，我们使用各种多阶段精加工模式对宽度从 5 毫米到 1 毫米不等、长度最长可达 50 毫米的方形横截面进行表面精加工。其次，我们使用高速相机和水下水听器测量来表征多相流，重点关注冷却通道内的空化效应。第三，我们进行了数值模拟并提取了通道内的空化和湍流动能分布。空化频率支持表面纹理结果（nf _o )、均方根压力 ( P _rms ) 和来自水听器的声能 ( E _A ) 观测值。最后，我们通过使用数值模拟结果改变通道尺寸和长度来解释表面精加工趋势。结果表明，空化相位分布随着通道尺寸的减小和通道长度的增加而减小。所提出的方法有助于建立适当的工艺参数，以实现沿整个通道长度的均匀表面光洁度。