Process for pretreating aluminium or aluminium alloy surfaces to be welded and accordingly pretreated parts

摘要

Process for surface pretreatment of aluminum (Al) and Al alloy welded parts where before welding the parts are polished and then treated in an acidic aqueous solution of boron (B) and/or silicon (Si) and/or titanium (Ti) and/or zirconium (Zr) and/or hafnium (Hf) ions. An independent claim is included for a welded Al or Al alloy part (claimed).