Internal Oxidation of Some Pd-40Ag-1RE Alloys

The internal oxidation behavior of Pd-40Ag-1RE(RE=Sin,Eu,Gd,Y)alloy wires has been studied in air at 800～1200℃The dependence of internal oxidation depth ξ on reaction time t can be expressed asξ=Kt~n,the reaction index n=0.50～0.75.The higher the oxidation temperature is.the larger the n value is.It means that the internal oxidation of wire sampls at high tem-perature deviates from parabola rule observed on plate sample.The activation energies of the studied alloys range over 120～160kJ/mol.The internal,oxidation process is controlled by the bulk diffusion of oxygen.