The microstructure of deformed nanocrystalline Ag and Ag/Fe alloy

Structures of alloys prepared by an inert-gas condensation and compaction method and subsequently rolled were examined with interest in the deformation mechanism. The initial grain size is found to be smaller in the alloy than in the single component material, but XRD measurements indicate that a normal preferred orientation of rolling is developed in the Ag/Fe alloy slightly but not in the Ag at all. The grain growth occurs more or less but hardness is not increased by deformation in both materials. Strain contrasts along grain boundaries are observed by TEM, but tangled dislocations are found in grain interior of neither of the deformed materials. The observation has indicated that the dominant mechanism of deformation in the examined nanocrystalline materials, especially in the single component material, is considered to be grain boundary sliding accomplished by a diffusional process.