THE EFFECT OF ALLOYING ELEMENTS ON THE CORROSION BEHAVIOR OF SPUTTER-DEPOSITED AMORPHOUS MN-TA-CR ALLOYS IN 1M H2SO4

The effect alloying tantalum and chromium on the corrosion resistance of amorphous manganese-base alloys was studied by weight-loss, electro chemical and XPS techniques. Amorphous alloys were formed in a wide co mposition range by the addition of tantalum to manganese-chromium allo ys. The corrosion rates of Mn-Ta-Cr alloys in 1 M H2SO4 open to air at 30 degrees C were about four and six orders of magnitude lower than t hose of MnTa and Mn-Cr alloys containing the same amount of manganese, respectively, and decreased with increasing alloy chromium content. T hus, additions of chromium and tantalum to manganese were synergistica lly effective in enhancing the corrosion resistance of Mn Ta-Cr alloys . The beneficial effect of chromium in the presence of tantalum is exp lained in terms of enhancement passivity and cathodic reactions of the alloys. (C) 1998 Published by Elsevier Science Ltd. All rights reserv ed.