<i>In situ</i> monitoring of initial plasma electrolytic oxidation process on 60 vol. % SiCp/2009 aluminum matrix composite by sound and vibration measurement techniques

The initial discharge process of plasma electrolytic oxidation (PEO) on the 60 vol. % SiCP/2009 aluminum matrix composite in silicate solution was situ monitored by sound and vibration measurement techniques. underwater sound, airborne sample signals were detected 120 s PEO process, their generation mechanism discussed. In terms waveforms spectrograms signals, can be divided into five stages: conventional anodizing stage (I), glow (Ⅱ), tiny spark (Ⅲ), large (Ⅳ), strong (Ⅴ). during are attributed to evolution bubbles, which from discharge, electrochemical reactions, vaporization electrolyte under Joule heat. I, these completely come bubbles produced evaporative reactions. stages Ⅱ–Ⅴ, gradually become main source with increasing intensity. addition, spike peaks at Ⅴ related sparks. These results demonstrate that techniques effectively monitor process.