Research On Mechanism Of Spark Assisted Chemical Engraving Based On High-Speed Camera Technology

With the development of aviation technology,in order to meet the requirements for better aero engine propulsion capabilities,the requirements for cooling and heat dissipation effects of engine turbine blades have gradually increased.In order to achieve this goal,the surface thermal barrier layer of turbine blades is gradually replaced by zirconium dioxide composite materials with better thermal insulation properties.However,zirconia itself has good heat resistance and high hardness,and it is impossible to process the air film holes on the blade surface through traditional processing methods.Spark Assisted Chemical Engraving(SACE)is a potential new type of processing technology for the non-damage processing of air film holes.This article mainly studies and discusses the processing mechanism and process optimization methods of SACE.This article first studies and analyzes the microscopic phenomena of SACE.Through the processing method of transparent workpiece sidewall processing and the observation method of high-speed camera,the whole process of SACE is summarized as three stages of rapid electrolysis,gas film formation,and gas discharge.The cyclical repeating process,and the quantitative analysis of the time distribution and gas-liquid morphology changes in different stages.Based on the further understanding of the gas-liquid mixing environment change law in the SACE process,this article focuses on the discharge process of SACE,and establishes a physical model of the discharge on the bottom surface of the electrode and the sidewall of the electrode based on the principle of tip discharge,and the spatial position distribution of the discharge point and the transfer of the discharge point The rules are summarized and explained.Using the image algorithm threshold recognition technology,a comprehensive evaluation index system for the discharge effect is established,and the processing voltage and the processing gap are used as variables to explore the change law of the discharge effect under different conditions.Finally,based on the characteristics of the gas-liquid mixing environment in the SACE process and the variation of the discharge effect with the processing conditions,an optimization plan for the SACE tool electrode is proposed,and the optimized electrode and the ordinary electrode are compared from the two dimensions of the discharge effect and the actual processing effect.Conducted a comparative experiment.It is verified that the optimized electrode has advantages in terms of discharge energy utilization efficiency and processing efficiency,but there are still shortcomings in the flatness of the processed surface.