Accession Number : ADA291315

Title :   MM-Wave Resonant Methods for the Detection of Corrosion. Phase 1.

Descriptive Note : Final rept. 15 Jun-14 Dec 94,

Corporate Author : CONDUCTUS INC SUNNYVALE CA

Personal Author(s) : Martens, J. ; Sachtjen, S.

PDF Url : ADA291315

Report Date : 10 FEB 1995

Pagination or Media Count : 38

Abstract : In this program, a class of mm-wave resonant tools known as surface resistance analyzers were evaluated for their ability to detect corrosion and extract information on corrosion products. The study was performed primarily on aluminum alloys exposed to salt fog conditions although a high temperature material sand steel alloys were also measured. The results on detection were uniformly encouraging. Statistically significant deviations in surface resistance were reported prior to visible corrosion products appearing. Incipient stress-related cracks around rivet holes were also detected on length scales of 0.1 mm. Complex permittivity data was extracted for the corrosion products and was used to estimated thicknesses, impurity levels, and composition changes during different exposure conditions. Incipient corrosion was also detected underneath several varieties of paint. The results suggest that this may be a useful measurement tool for the detection and analysis of corrosion in an aircraft maintenance environment. jg

Descriptors :   *DETECTION, *CORROSION, *MILLIMETER WAVES, *RESONANCE, STRESSES, MEASUREMENT, THICKNESS, ENVIRONMENTS, ALUMINUM ALLOYS, AIRCRAFT MAINTENANCE, EXPOSURE(GENERAL), TOOLS, RESISTANCE, CRACKS, SAND, IMPURITIES, ESTIMATES, SURFACES, DIELECTRIC PROPERTIES, HOLES(OPENINGS), SCALE, FOG, LENGTH, VISIBILITY, RIVETS, LEVEL(QUANTITY), PAINTS, ANALYZERS, SALT WATER.

Subject Categories : Properties of Metals and Alloys
      Inorganic Chemistry
      Physical Chemistry
      Radiofrequency Wave Propagation

Distribution Statement : APPROVED FOR PUBLIC RELEASE