Chromate free anodising

BSAA, now being called a chromate-free anodising process [35], theoretically uses no chromate salts in the cleaning stages or as the electrolyte. A minor exception to this chromate-free concept does, however, occur as some operators use a tri-acid based deoxidiser which does contain some chromic acid together with sulphuric and hydrofluoric acids. 

Yendall, K. A., Critchlow, G. W., Andrews, F. R., Bahrani, D. (2002). An evaluation of chromate-free anodising processes for aerospace applications. Extended abstracts for Euradh 2002. lOM Communications, London. 

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