Research on a Compensation Correction Algorithm for the Removal Function of Atmospheric-Pressure Plasma Processing

Atmospheric-pressure plasma processing (APPP) is an important method for the fabrication of high-precision optics because it involves highly efficient and nondamaging material removal based on its pure chemical etching mechanism. However, owing to the heat accumulation phenomenon caused by the jet heat flux, the nonlinearity of the material removal rate in APPP is inevitable, making it difficult to achieve deterministic optical surfacing. To bridge this gap, this study focused on analyzing the nonlinear relationship between the material removal rate and heat accumulation. The simulation results indicated that when the sliding distance increased from 10 to 50 mm, the surface temperature of the workpiece increased from 387.3 to 419.5 K, an increase of more than 8%. When the dwell time increased from 0.33 to 2 s, the surface temperature of the workpiece increased from 348.1 to 419.5 K (including the effect of sliding distance), an increase of more than 21%. A novel algorithm that simultaneously considers dwell time and sliding distance was proposed based on the results. A threshold parameter t_q was introduced to determine whether to correct the deviation caused by the sliding distance. With the proposed algorithm, the matching residual surface root-mean-square (RMS) error decreased from 97.5 to 39.6 nm. The RMS deviation error of the matching residual surface error converged from 11.6 to 4.7% after surface-figuring experiments. The proposed algorithm is expected to provide a promising solution for future deterministic optical surfacing.