Research On Preparation And Property Of Fiber Bragg Grating Sensor For Corrosion Based On Aluminum Film

Aluminum and aluminum alloys are very important light metal materials and have become an economic competitor in engineering applications. Aluminum offers a wide range of properties that can be engineered precisely to the demands of specific application. The properties of alumimun and its alloys which give rise to their widespread usage include high thermal and electrical conductivity, high strength, ease of fabrication and inexpensive price. Aluminum is used extensively in aerospace, transportation, construction, communications and electronics industry. Great destructive effects of corrosion in modern industry bring about enormous economic loss and social harm to humans. Hence, to monitor aluminum corrosion in-situ and online provides critical data of materials for structural assessment and maintenance measures, the need to maintain national product protection.The fiber bragg grating(FBG) sensors are a group of advanced, non-destructive, real-time and efficient optic sensors for structural evaluations. In recent years, there has been developed a series of methods for monitoring corrosions of aluminum alloy. The fiber optic sensors have become a new research hotspot in monitoring corrosion for its advantages of high reliability, stability, built-in transmission and sensing function and high accuracy.The preparation of a fiber bragg grating sensor for monitoring aluminum corrosion is proposed in this thesis, at the same time, characteristics of the sensor in different environments are also discussed. The sensor can be used to establish distributed sensing system for non-destructive and real-time monitoring of aluminum corrosion status and to provides alert signals of severe aluminum corrosion. The main research work and findings in this thesis are concluded as:1. A fiber bragg grating sensor for aluminum corrosion based on aluminum film is designed. The analysis of aluminum corrosion morphology and curve of FBG center wavelength drift in simulate corrosion solution showed the feasibility of this sensor for aluminum corrosion monitoring. The sensing performances of the FBG corrosion sensor after treatment of annealing or boiling water on the aluminum film are also discussed, and it’s proved that the above treatments can improve the corrosion resistance of aluminum.2. The performance of the new sensor is systematically tested in a constant humidity, acid, alkaline environments and the chloride-contaminated solution. The results turned out that the evolution trend of the wavelength and width is corresponding to the aluminum corrosion status.3. With the corrosion mechanism of iron and aluminum, compared to the different performances of FBG based on Fe-C film and aluminum film. The result proves the effectiveness of the sensor, and provide FBG with a broad exploration space for detecting corrosion of different metals.