Evaluation of Conversion Coatings Without Hexavalent Chromium for Aerospace and Defense Applications

Conversion coatings containing hexavalent chromium are currently used in aerospace and defense manufacturing on various aluminum alloys to provide corrosion protection and enhanced adhesion of subsequent coatings. However, hexavalent chromium is toxic to humans with negative health effects from acut...

Full description

Bibliographic Details
Main Authors: Gregory Morose, David Pinsky, Chandler Humphrey, Kent DeFranco
Format: Article
Language:English
Published: Instituto de Aeronáutica e Espaço (IAE) 2022-02-01
Series:Journal of Aerospace Technology and Management
Subjects:
Online Access:https://www.jatm.com.br/jatm/article/view/1248
_version_ 1818096509195911168
author Gregory Morose
David Pinsky
Chandler Humphrey
Kent DeFranco
author_facet Gregory Morose
David Pinsky
Chandler Humphrey
Kent DeFranco
author_sort Gregory Morose
collection DOAJ
description Conversion coatings containing hexavalent chromium are currently used in aerospace and defense manufacturing on various aluminum alloys to provide corrosion protection and enhanced adhesion of subsequent coatings. However, hexavalent chromium is toxic to humans with negative health effects from acute and chronic exposure. Regulatory mandates have accelerated a global effort to replace hexavalent chromium-containing materials because of their toxicity. A consortium was established to evaluate safer conversion coating materials, including the chemical processing of the surfaces prior to applying the conversion coatings. Four conversion coatings without hexavalent chromium were compared against a hexavalent chromium-based conversion coating for the following tests: coating weight, electrical contact resistance, paint adhesion, bare and painted neutral salt fog corrosion tests, painted SO2 salt fog corrosion test, and painted outdoor beachfront corrosion test. The test results for the four conversion coatings without hexavalent chromium were encouraging since several candidates exceeded some of the specification requirements or consortium expectations. In particular, the Socosurf TCS/PACS conversion coating performed well in the coating weight, electrical contact resistance, paint adhesion, and corrosion tests. The results of this evaluation provide significant progress toward providing a replacement material for a traditionally hexavalent chromium material application on aluminum.
first_indexed 2024-12-10T23:05:45Z
format Article
id doaj.art-ff805a95e8284a6e85cff0c3fc6620a9
institution Directory Open Access Journal
issn 2175-9146
language English
last_indexed 2024-12-10T23:05:45Z
publishDate 2022-02-01
publisher Instituto de Aeronáutica e Espaço (IAE)
record_format Article
series Journal of Aerospace Technology and Management
spelling doaj.art-ff805a95e8284a6e85cff0c3fc6620a92022-12-22T01:30:03ZengInstituto de Aeronáutica e Espaço (IAE)Journal of Aerospace Technology and Management2175-91462022-02-0114Evaluation of Conversion Coatings Without Hexavalent Chromium for Aerospace and Defense ApplicationsGregory MoroseDavid PinskyChandler HumphreyKent DeFrancoConversion coatings containing hexavalent chromium are currently used in aerospace and defense manufacturing on various aluminum alloys to provide corrosion protection and enhanced adhesion of subsequent coatings. However, hexavalent chromium is toxic to humans with negative health effects from acute and chronic exposure. Regulatory mandates have accelerated a global effort to replace hexavalent chromium-containing materials because of their toxicity. A consortium was established to evaluate safer conversion coating materials, including the chemical processing of the surfaces prior to applying the conversion coatings. Four conversion coatings without hexavalent chromium were compared against a hexavalent chromium-based conversion coating for the following tests: coating weight, electrical contact resistance, paint adhesion, bare and painted neutral salt fog corrosion tests, painted SO2 salt fog corrosion test, and painted outdoor beachfront corrosion test. The test results for the four conversion coatings without hexavalent chromium were encouraging since several candidates exceeded some of the specification requirements or consortium expectations. In particular, the Socosurf TCS/PACS conversion coating performed well in the coating weight, electrical contact resistance, paint adhesion, and corrosion tests. The results of this evaluation provide significant progress toward providing a replacement material for a traditionally hexavalent chromium material application on aluminum.https://www.jatm.com.br/jatm/article/view/1248Conversion coatingHexavalent chromiumCorrosion testPaint adhesionAluminum alloy
spellingShingle Gregory Morose
David Pinsky
Chandler Humphrey
Kent DeFranco
Evaluation of Conversion Coatings Without Hexavalent Chromium for Aerospace and Defense Applications
Journal of Aerospace Technology and Management
Conversion coating
Hexavalent chromium
Corrosion test
Paint adhesion
Aluminum alloy
title Evaluation of Conversion Coatings Without Hexavalent Chromium for Aerospace and Defense Applications
title_full Evaluation of Conversion Coatings Without Hexavalent Chromium for Aerospace and Defense Applications
title_fullStr Evaluation of Conversion Coatings Without Hexavalent Chromium for Aerospace and Defense Applications
title_full_unstemmed Evaluation of Conversion Coatings Without Hexavalent Chromium for Aerospace and Defense Applications
title_short Evaluation of Conversion Coatings Without Hexavalent Chromium for Aerospace and Defense Applications
title_sort evaluation of conversion coatings without hexavalent chromium for aerospace and defense applications
topic Conversion coating
Hexavalent chromium
Corrosion test
Paint adhesion
Aluminum alloy
url https://www.jatm.com.br/jatm/article/view/1248
work_keys_str_mv AT gregorymorose evaluationofconversioncoatingswithouthexavalentchromiumforaerospaceanddefenseapplications
AT davidpinsky evaluationofconversioncoatingswithouthexavalentchromiumforaerospaceanddefenseapplications
AT chandlerhumphrey evaluationofconversioncoatingswithouthexavalentchromiumforaerospaceanddefenseapplications
AT kentdefranco evaluationofconversioncoatingswithouthexavalentchromiumforaerospaceanddefenseapplications