Quality Control Technology for Abrasive Flow Precision Machining of a High-Performance Impeller

The surface quality of high-performance impellers, which feature complex, free-form surfaces and narrow flow channels, is critically important for their performance and efficiency. However, achieving uniform precision polishing on these intricate geometries remains a significant manufacturing challenge, as traditional methods are often inefficient, inaccessible, or cause surface damage. To address this, this study investigates the application of solid-liquid two-phase abrasive flow machining (AFM) as a high-precision finishing solution. Through numerical simulation, we analyzed the polishing effects under two flow channel structures and various machining parameters. The results demonstrate that a gradual flow channel structure significantly enhances processing uniformity and intensity compared to a direct flow channel. Furthermore, increasing the inlet pressure and abrasive viscosity was found to substantially improve both the strength and uniformity of the machining effect across the impeller surface. Experimental validation via an orthogonal test design confirmed that inlet pressure is the most influential factor on the polishing effect, followed by abrasive grain size and the number of processes. The optimized process parameters (6 MPa inlet pressure, 10 process cycles, and 40 µm abrasive grain size) successfully reduced the average surface roughness (Ra) of the high-performance impeller from 0.766 µm to 0.047 µm, representing an improvement of nearly 94%. This study provides a scientifically grounded set of optimal parameters for achieving uniform, high-quality surface finishing of complex impellers using AFM technology.