J. Mater. Sci. Technol. ›› 2021, Vol. 67: 197-210.DOI: 10.1016/j.jmst.2020.06.038

• Research article • Previous Articles     Next Articles

Influence of LDH conversion coatings on the adhesion and corrosion protection of friction spot-joined AA2024-T3/CF-PPS

A.C. Boualia,*(), N.M. Andréb, M.R. Silva Camposa, M. Serdechnovaa, J.F. dos Santosb, S.T. Amancio-Filhoc, M.L. Zheludkevicha,d   

  1. a Institute of Materials Research, Helmholtz-Zentrum Geesthacht, Magnesium Innovation Centre, Corrosion and Surface Technology, Max-Planck-Straße 1, 21502 Geesthacht, Germany
    b Institute of Materials Research, Helmholtz-Zentrum Geesthacht, Materials Mechanics, Solid State Joining Processes, Max-Planck-Straße 1, 21502 Geesthacht, Germany
    c Graz University of Technology - TU Graz, Institute of Materials Science, Joining and Forming, BMK Endowed Professorship for Aviation, Kopernikusgasse 24/1, 8010 Graz, Austria
    d Faculty of Engineering, University of Kiel, Kaiserstrasse 2, 24143 Kiel, Germany
  • Received:2020-05-09 Revised:2020-06-29 Accepted:2020-06-30 Published:2021-03-20 Online:2021-04-15
  • Contact: A.C. Bouali
  • About author:* E-mail address: anissa.bouali@hzg.de (A.C. Bouali).

Abstract:

Layered double hydroxide (LDH) conversion coatings loaded with corrosion inhibitors were suggested for the surface treatment of the aluminum alloy 2024-T3, prior to friction spot joining with carbon-fiber reinforced polyphenylene sulfide (AA2024-T3/CF-PPS). Vanadate was used as a model corrosion inhibitor. Lap shear testing method revealed an increase of approx. 20% of the joint’s adhesion performance when treated with LDH and before exposure to salt spray. The evaluation of the joints after exposure to salt spray demonstrated a significant difference in the corrosion behavior of the joints when the AA2024-T3 is treated with LDH loaded with nitrate and vanadate species. The LDH intercalated with nitrate revealed a clear improvement in the mechanical and corrosion resistance performance of the joints, even after 6 weeks of salt spray. However, the LDH intercalated with vanadate failed in providing protection against corrosion as well as preserving the mechanical properties of the joints. The effect of the galvanic corrosion was further investigated by zero resistance ammeter (ZRA) measurements as well as localized scanning vibrating electrode technique (SVET).

Key words: Friction spot joining, Layered double hydroxide, Galvanic couple, Corrosion protection, Adhesion