A polishing method using self-excited oscillation abrasive flow for the inner surface of workpiece

To better polish the inner surface of the pipe fittings and hole parts, this paper proposed a novel polishing method that was based on the self-excited oscillating pulse effect of abrasives flow. Firstly, the basic principle of self-excited oscillating polishing flow was introduced, and then the simulation model and experimental platform of a self-excited oscillating abrasive flow polishing were established. Through fluid simulation and stainless steel inner surface polishing experiments, the relationships between polishing parameters (inlet velocity, inlet initial gauge pressure, abrasive particle concentration, and abrasive particle size), turbulence intensity, and wall shear forces were analyzed. The results of experiments showed that the factors affecting the variation of roughness are sorted from large to small into inlet velocity, inlet initial gauge pressure, abrasive particle concentration, and abrasive particle size. In addition, A polishing comparison experiment was carried out. At the inlet A, the inner surface roughness Ra can reach 46 nm after 14 h of polishing without an oscillation cavity, while in the case of a self-excited oscillation cavity, the inner surface roughness Ra can reach 46 nm after 12 h of polishing. Compared with the non-oscillating abrasive flow polishing, the polishing efficiency with the self-oscillating abrasive flow is 15% higher, and the over-polishing phenomenon can be suppressed.