Study On Chloride Ion Monitoring Technology Of Micro-Liquid Membrane In Salt Spray Corrosion Environment Of Aviation Equipment

With the worsening service environment of naval aviation equipment in our country,the corrosion maintenance cost of marine atmospheric environment to aviation equipment becomes larger and the maintenance procedure of aircraft is complex.The corrosion problem of aviation equipment has been studied at home and abroad.Because of the diffic?Lty in checking and maintaining the internal structure of aviation equipment,some foreign airlines and domestic research institutions have put forward the demand of online monitoring for the corrosion environment of salt spray in aviation equipment.Based on the above situation,three kinds of micro-liquid membrane chloride ion sensors with different measuring principles were studied,and real-time monitoring of chloride ion concentration in salt spray corrosion environment was realized.The main contents of this paper are as follows:Firstly,aiming at the corrosion problem faced by aircraft in coastal service,the urgency and existing problems of environmental monitoring for internal equipment of aircraft are s?mmarized.The chloride concentration is selected as the representative monitoring parameter of corrosion environment,in order to realize the real-time monitoring of chloride concentration in corrosion environment of aircraft.Secondly,based on the principle of electrochemistry,a liquid-filled double-electrode chloride ion sensor was developed to measure chloride ion concentration in micro-liquid membrane according to Nernst equation.The res?Lts show that the linearity of calibration curve is 0.9816-0.9936,the sensitivity is 30.14-31.7 mV/lnCl-,and the drift rate is 1.8-1.9 mV/h,which meets the requirements of application.Aiming at the temperature drift of the sensor,a temperature compensation method for chloride ion sensor is proposed.The chloride ion concentration of each temperature gradient can be measured completely by calibrating a small n?mber of temperature points.Thirdly,a chloride ion sensor based on screen printing technology is studied.The bare silver/silver chloride electrode was prepared by screen printing technology.The pHEMA hydrogel was modified on the surface of the reference electrode by Sol-Gel method,and the sensor was f?Lly solid-state.The experimental res?Lts show that the linearity of the calibration curve is 0.996,the sensitivity is 24.27-25.89mV/lnCl-,the lifetime is longer than two weeks,and the drift rate is 0.9-1.6mV/h.Finally,based on Fick diffusion theory and chronopotentiometry theory,a four-electrode solid-state interdigital chloride ion sensor is proposed.The calibration curve linearity of the sensor is about 0.9725 in the range of 0.1-1 mol/L NaCl micro-liquid film.The sensitivity of the sensor is 2.38s1/2/(mol/L).The error of chloride concentration measurement within 72 hours is less than 4.2%.It shows that the sensor has good stability and sensing ability.The experimental res?Lts of pH interference show that the measurement error of the sensor is less than 7% in the range of pH 1-9,which indicates that the sensor has strong anti-interference ability.