ISO/CD 21746 standard galvanic corrosion testing procedures for CFRP-metal assemblies

Tetsuya Morimoto, Hisaya Katoh, Eiichi Hara, Yutaka Iwahori

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Abstract

Galvanic corrosion in carbon fiber-reinforced plastic (CFRP) metal assemblies is a new and rising issue in aerospace structural design that is hindering the expansion of CFRP applications. The wide gap of galvanic potential between the metallic materials and the CFRPs cause an electrochemical reaction in the cell to occur that results in severe corrosion. Therefore, the evaluation of protection methods such as calking, inhibitor painting, and water sealants using standardized procedures is essential. Present procedures such as ISO 9227 are intended for isolated samples. As such, galvanic paired samples of CFRP-metal assemblies are beyond their scope. As a result, the authors propose a new draft of the standard test ‘ISO/CD 21746 composites and metal assemblies — galvanic corrosion tests,’ which has been approved through a committee draft (CD) vote of the ‘Technical Committee ISO/TC 61, Plastics - Subcommittee SC 13, Composites and reinforcement fibers.’ In this paper, the authors evaluate the procedures through a series of galvanic corrosion tests for CFRP-A1 bolted assemblies of Toray T800S/3900-2B composites and A1 1050P in direct contact with conductive bolts for three cases: no insulation, insulating film interface, and insulating film interface with insulated bolts. The results from the test chamber evaluations show that the proposed CD 21746 standards are excellent for evaluating galvanic corrosion and that they have user-friendly descriptions. In addition, the newly defined pure A1 reference specimens in these standards are relatively inexpensive compared to the CR4 grade steel and pure zinc specimens of the present ISO 9227 standard.

Original languageEnglish
Title of host publicationAIAA/ASCE/AHS/ASC Structures, Structural Dynamics, and Materials
PublisherAmerican Institute of Aeronautics and Astronautics Inc, AIAA
Edition210049
ISBN (Print)9781624105326
DOIs
Publication statusPublished - 1 Jan 2018
EventAIAA/ASCE/AHS/ASC Structures, Structural Dynamics, and Materials Conference, 2018 - Kissimmee, United States
Duration: 8 Jan 201812 Jan 2018

Publication series

NameAIAA/ASCE/AHS/ASC Structures, Structural Dynamics, and Materials Conference, 2018
Number210049

Conference

ConferenceAIAA/ASCE/AHS/ASC Structures, Structural Dynamics, and Materials Conference, 2018
CountryUnited States
CityKissimmee
Period8/01/1812/01/18

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Morimoto, T., Katoh, H., Hara, E., & Iwahori, Y. (2018). ISO/CD 21746 standard galvanic corrosion testing procedures for CFRP-metal assemblies. In AIAA/ASCE/AHS/ASC Structures, Structural Dynamics, and Materials (210049 ed.). (AIAA/ASCE/AHS/ASC Structures, Structural Dynamics, and Materials Conference, 2018; No. 210049). American Institute of Aeronautics and Astronautics Inc, AIAA. https://doi.org/10.2514/6.2018-1372