X-Ray Studies of Plastically Deformed Silver Alloys - Effects Due to Oxygen, Hydrogen, and Tin Solutes*

Abstract

AbstractSolid specimens of silver were charged at different temperatures in atmospheres of oxygen and of hydrogen. X-ray diffraction line profiles were obtained using powders filed from the treated specimens. Fourier analysis of the diffraction lines was conducted following the method of Warren. The effective particle sizes and root-mean-square strains were obtained from the line shape analysis. Stacking fault and twin fault probabilities were determined from peak-position and center-of gravity displacements, respectively. For the purpose of comparison, two vacuum-melted silver samples and two different silver-tin alloys were studied. The stacking fault and twin fault probabilities were observed to be nearly unaffected by charging in either oxygen or hydrogen. These results are consistent with recent direct determinations of the effect of oxygen on the stacking fault energy of silver. In contrast, the rms strains and particle sizes changed significantly after charging in oxygen. A decrease in the root-mean-square strain and a corresponding increase in the particle size was found. These effects were opposite to those obtained by adding substitutional solute to silver. These findings are interpreted to indicate the effect of oxygen clustered with impurities on the dislocations and stacking faults in silver.