Stress Corrosion Cracking of Silver-Gold Alloys in 1 M Potassium Chloride, Potassium Bromide, and Potassium Iodide Solutions

Abstract

Silver-gold (Ag-Au) alloys (2.2 at% to 60 at% Au) were found susceptible to stress corrosion cracking (SCC) in 1 M potassium chloride (KCl), 1 M potassium bromide (KBr), and 1 M potassium iodide (KI) aqueous solutions. Cracks were mainly intergranular, and there was no evidence of a minimum Au content below which no SCC could be observed. According to the surface-mobility mechanism for up to 15 at% Au, the surface mobility of Ag, induced by the environment, was the rate-controlling step. For higher Au contents, Au surface mobility played an increasing role. Above 40 at%, it became rate controlling.