Fabrication Of Sensitive Film On A Carbon Steel Fiber Optics Corrosion Sensor And Study On The Sensing Capability

In recent years as a new technique of corrosion detection FiberOptics Corrosion Sensors(FOCS) have been widly concerned in bigbuildings , aircraft and many other fields. But there are still somedeficiency in actual application of these FOCS. This paper fabricates aFe-C alloy sensing film on a carbon steel FOCS by groping for arts andcrafts, which can predigest the technics and reduce the cost ofmanufacturing the sensor. And then it establishes the basis for realizingthe appliance in practical engineering. Many methods, such as PVD (Physical Vacuum Deposit),electroplating, etc, have been explored on quartz glass in order to form aFe-C alloy film with better quality. The metallic transformation onsurface of quartz glass is the key craft including PVD carbon steel,magnetic controlled spatter nickel (Ni) and vacuum deposit aurum (Au).The better technical parameters such as disposal on surface of quartzglass, metallic transformation, parameters of electroplating, etc, havebeen ascertaind through a large number of experiments. Then thethickness of Fe-C alloy film made by different methods was measured,the surface morphologie of that was investigated and the structure ofthat was studied. Electrochemical method was used to evaluate thecorrosive resistance of the Fe-C alloy film in NaCl (sodium chloride)solution of different concentration. Two crafts that PVD associated withelectroplating and vacuum deposit Au associated with electroplating canbe used onto a fiber core, thereinto the Fe-C alloy film fabricated by thesecond method has more effect on a fiber core. To evaluate the sensing performance of the carbon steel FOCS, asystem was designed to test the sensing capability of Fe-C alloy film.The changing disciplinarian of light output power in the process of thesensitive film corrosion and influence factors of that were pilot studiedusing optical means. And then the sensing capability of Fe-C alloy filmfabricated by electroplating on PVD film and on Au film was been testedrespectively. The results show that the sensing capability of these ＩＩsensitive films made by the two methods accord with sensing principle;the middle metallic layer (viz. PVD film and Au film) has some negativeeffects on light output power. This minus influence brought from Au filmis more than that produced by PVD film. But after the Fe-C alloy whichis fabricated by electroplating on Au film corroded, the variety range ofthe light output power is more larger. It means that the sensingperformance and applicable foreground of the sensing film electroplatedon aurum film are greater. It can be believed that the quantitativerelation between the changing disciplinarian of light output power andthe corrosion course of sensing film will be found with the sequentiallucubration, and which also can contribute to the veracity of the carbonsteel FOCS in corrosion detection.