Electrochemical Impedance Pattern Recognition for Detection of Hidden Chemical Corrosion on Aircraft Components. Phase 1.

reportActive / Technical Report | Accession Number: ADA291345 | Open PDF

Abstract:

This investigation addressed the need for diagnostic instrumentation compatible with performing the Nondestructive Evaluation NDE of hidden chemical corrosion with a high degree of accuracy, sensitivity and versatility on both titanium and aluminum alloys currently used in Air Force and commercial aircraft. The overall approach was directed towards development of pattern recognition schemes based upon the on-line data acquisition of Fast Fourier Transform Electrochemical Impedance Spectroscopy FFTEIS instrumentation from the suspect hidden chemical corrosion site. Resulting impedance patterns were then analyzed by application of a Neural Network pattern recognition scheme. The Neural Network Analysis NNA was then trained to both detect and grade the severity of hidden corrosion present on the aircraft metal substrate interface of interest. Nueral Net Analysis of FFTEIS data was verified as a powerful diagnostic strategy for in situ hidden corrosion process identification, quantitative analysis and severity grading. Correlations between impedance measurements and corrosion depth were verified by subsequent SEM and EDX examination of the metal interfacial regions. The approach will also be powerful for gaining fundamental information into the nature of corrosion processes and conditions leading to their inception at hidden sites. jg

Author(s):
Sammells, A. F. ; Bowers, J. S.
Author Organization(s):
ELTRON RESEARCH INC BOULDER CO
Descriptive Note:
Final rept. 15 Jun-15 Dec 94,
Pagination:
0087

Security Markings

DOCUMENT & CONTEXTUAL SUMMARY

Distribution:
Approved For Public Release

RECORD

Collection: TR
Identifying Numbers
Report Number(s):
AFOSR-TR-95-0106
Contract/Grant Number(s):
F49620-94-C-0043
Task Number(s):
SS
Project Number(s):
3005
Monitor Series:
TR-95-0106, AFOSR
 Subject Terms
Joint Capability Areas:
JCA_5_Command and Control; JCA_5.3_Planning; JCA_5.5.2_Task; JCA_5.5_Direct; JCA_5.3.3_Develop Strategy; JCA_5.3.4_Develop Courses of Action; JCA_5.3.5_Analyze Courses of Action; JCA_1.2.1_Training; JCA_1.3.2_Personnel Management; JCA_4.5.4_Requirements Definition; JCA_4.5_Operational Contract Support
Modernization Areas:
Microelectronics
Communities of Interest:
Advanced Electronics
Descriptor(s):
*DETECTION, *CORROSION, *ELECTROCHEMISTRY, *PATTERN RECOGNITION, *AIRCRAFT EQUIPMENT, *IMPEDANCE, METALS, MEASUREMENT, AIR FORCE, SCANNING ELECTRON MICROSCOPES, QUANTITATIVE ANALYSIS, NEURAL NETS, DISPERSING, HIGH RATE, COMMERCIAL AIRCRAFT, NONDESTRUCTIVE TESTING, ALUMINUM ALLOYS, CHEMICALS, INTERFACES, ENERGY, ACCURACY, SUBSTRATES, X RAYS, DEPTH, IDENTIFICATION, DATA ACQUISITION, DIAGNOSIS(GENERAL), DIAGNOSTIC EQUIPMENT, FAST FOURIER TRANSFORMS, TITANIUM, NETWORK ANALYSIS(MANAGEMENT), ONLINE SYSTEMS, FOURIER SPECTROSCOPY
Field(s)/Group(s):
Physical Chemistry, Aircraft, Inorganic Chemistry, Properties of Metals and Alloys
Keyword(s):
FFTEIS(FAST FOURIER TRANSFORM ELECTROCHEMICAL IMPEDANCE SPECTROSCOPY), NNA(NEURAL NETWORK ANALYSIS), NEURAL NETWORK ANALYSIS, EDX(ENERGY DISPERSIVE X RAY), PE65502F, WUAFOSR3005SS
Report Date:
1995 Feb 08