Composite film formed on magnesium alloy AZ31 by chemical conversion from molybdate/phosphate/fluorinate aqueous solution toward corrosion protection

► Mo-P-F composite films were formed on magnesium alloy AZ31 by chemical conversion. ► The film consists of mixed phases composed mainly of Mg(OH)2, MoO2, MoO3, and MgF2. ► Corrosion resistance of the film was investigated by electrochemical measurements.