Accession Number : ADA295000

Title :   Infrared Detection of Chemical Corrosion on Metal Surface.

Descriptive Note : Final rept. 15 Jun 94-15 Mar 95,

Corporate Author : AERODYNE RESEARCH INC BILLERICA MA

Personal Author(s) : Dai, Qing ; Freeman, Andrew ; Robinson, Gary N.

PDF Url : ADA295000

Report Date : 15 MAR 1995

Pagination or Media Count : 35

Abstract : The sulfuric acid-induced corrosion of smooth (20 A average roughness) aluminum surfaces has been studied in real time using an in situ Fourier transform infrared reflection absorption spectrometer (IRAS) and a quartz crystal microbalance. Submicron-thick, 35 - 55 wt% (5- 12 molal), sulfuric acid films were formed on room temperature metal surfaces by the reaction of gas phase SO3 and H2O vapor in a flowing gas system at a total pressure of approx. 200 Torr. Using changes in spectral features that are linked to the production of Al(3+) as indicators of corrosion, we conclude the rate of corrosion of the metal is strongly enhanced by both higher relative humidities and increased rates of sulfuric acid deposition. Ex situ IRAS measurements on aluminum foils indicated that this technique is suitable for the detection of corrosion on metal surfaces. jg

Descriptors :   *INFRARED DETECTION, *METALS, *CORROSION, *CHEMICALS, *SURFACES, DETECTION, PRODUCTION, REAL TIME, FILMS, CRYSTALS, REFLECTION, PHASE, ROOM TEMPERATURE, SPECTRA, QUARTZ, ALUMINUM, FOILS(MATERIALS), ABSORPTION, INDICATORS, HUMIDITY, SPECTROMETERS, GAS FLOW, SULFURIC ACID, FOURIER SPECTROSCOPY, ACID DEPOSITION, MICROBALANCES.

Subject Categories : Inorganic Chemistry
      Physical Chemistry
      Properties of Metals and Alloys
      Optics

Distribution Statement : APPROVED FOR PUBLIC RELEASE