<title>Aluminum alloy clad fiber optic corrosion sensor</title>

Abstract

Life extension programs for military metallic aircraft are becoming increasingly important as defense budgets shrink and world economies realign themselves to an uncertain future. For existing military weapon systems, metallic corrosion damage costs an estimated $8 billion per year. One approach to reducing this cost is to develop a reliable method to detect and monitor corrosion in hidden metallic structure with the use of corrosion sensors which would give an early indication of corrosion without significant disassembly, thereby reducing maintenance costs. This presentation describes the development, analysis, and testing of a fiber optic corrosion sensor developed jointly with the Virginia Polytechnic Fiber & Electro-Optics Research Center and sponsored by Wright Laboratory Materials Directorate, contract #F33615-93-C-5368. In the sensor which was researched under this contract, the normal cladding is removed in the sensor region, and replaced with aluminum alloy and allowed to corrode on coupons representative of CIKC-135 body structure in an ASTM B 1 17 salt spray chamber and a Boeing developed Crevice Corrosion Cell. In this approach, the optical signal output of the sensor was originally designed to increase as corrosion takes place, however interaction with the corrosion byproducts yielded different results than anticipated. These test results to determine a correlation between the sensor output and the structural degradation due to corrosion are discussed.

A fibre optic corrosion fuse sensor using stressed metal-coated optical fibres

“…• changes in the transmitted optical power of metal-coated fibres using the evanescent field [4][5][6], • fibre Bragg grating sensors [7][8][9][10][11], • spectroscopic sensors [12][13][14][15], or, • the use of an optical fibre to monitor the failure of a bulk material due to corrosion [16].…”

Effects of chemical modification on fusion splicing strength and optical parameters of optical fiber

“…They can be applied under adverse environmental conditions such as strong electromagnetic fields, high voltage, and nuclear radiation and in explosive or chemically aggressive media as well as at high temperatures. 2,3 Inevitably, fusion splicing techniques are usually employed as a tool in various environments to produce a desired length.…”

Effects of chemical modification on fusion splicing of optical fiber and preparation of fiber corrosion sensor

“…They can be applied under adverse environmental conditions like strong electro-magnetic fields, high voltage, nuclear radiation, in explosive or chemically aggressive media as well as at high temperatures [1,2] .…”