The corrosion behavior of sputter-deposited amorphous CrNb and CrTa alloys in 12 M HCl solution

Abstract

Binary CrNb and CrTa alloys containing 29–63 at% niobium and 26–69 at% tantalum, respectively, with a single phase amorphous structure, were formed by a sputtering method. Corrosion rates of amorphous CrNb alloys were about four orders of magnitude lower than that of chromium metal and about one fifth of that of niobium metal in 12 M HCl solution. Corrosion rates of amorphous CrTa alloys were lower than that of tantalum metal and were not detected even after about 1 week immersion in 12 M HCl solution. The CrNb and CrTa alloys were spontaneously passive in 12 M HCl solution, in spite of the fact that chromium dissolved actively in 12 M HCl solution.