Elaboration of an optical fibre corrosion sensor for aircraft applications

As the fleet of both civilian and military aircraft ages, the need for understanding the effects of corrosion becomes increasingly important. So, our goal is to develop an optical fibre corrosion sensors (OFCS), fabricated by thermal deposition of an aluminium film onto an optical fibre core within the sensing region in order to follow corrosion in aeronautic structures. The OFCS is tested by two methods: optical and electrochemical methods for different aluminium thickness deposited, in different acid concentration. The mechanisms of corrosion (uniform or in preferential places) can be deduced from the optical signal. The sensitivity of the OFCS is good for the low thickness. Corrosion rates for aluminium and copper are quite different, the effect of oxide layer on aluminium is important and induces corrosion in several stages.