REACh will ban chromium VI, the sunset date approaches

ESA (European Space Agency) contracted ISQ to conduct a comparative study to find alternatives to hexavalent chromate conversion coatings.

The aim of this independent study was to test various solutions:

  • baseline for all test: BONDERITE M-CR 1200 (Alodine 1200) 
  • products tried: SOCOSURF TCS / SOCOSURF PACS, SURTEC 650V and BONDERITE M-NT 65000 
  • challenge: protection on different aluminium alloy substrates (2024 T3, 2024 T81, 7075 T73, 6061 T6 and 5083 H111)

A solution for aluminium conversion coating with good SST performances

This independent study ranks SOCOSURF TCS / SOCOSURF PACS as Nº1 solution.

  1. Phase 1 of the evaluation
    SOCOSURF TCS / SOCOSURF PACS is one of the most promising chemical conversion alternatives for all the aluminium alloys, including AA2024.”
  2. Phase 2 – extended testing
    SOCOSURF TCS / SOCOSURF PACS is the only alternative to BONDERITE M-CR 1200 that passed 336 hrs neutral salt spray with less than 5 pits on all alloys.
  3. More testing were done:
    such as resistivity checks MIL DTL 81706, humidity testing ASTM D2247 and thermal cycling
  4. Last phase of the evaluation – “Long Term Environmental Test Programme”
    SOCOSURF TCS / SOCOSURF PACS was selected as a stand-alone protection and with primers & topcoats.

SOCOSURF TCS and SOCOSURF PACS are an alternative process to chromium VI for conversion treatments and for sealing after anodizing. On aluminium alloys, the corrosion protection provided is comparable to the hexavalent chromium effect.

Reference: European Space Agency – Clean Space industrial days (27 Oct 2017)
Alternative pre-treatments to aluminium Replacements for Hexavalent Chromate Conversion Coatings

To know more about Aluminium Surface Treatment, download the brochure: