Microstructure and texture development in oxide-dispersion strengthened silver rods processed by hot-extrusion

The present paper reports on an investigation of the microstructures and textures of different industrially manufactured and commercially available oxide-dispersion strengthened silver alloys upon hot-extrusion at temperatures above 800 degrees C. In all alloys with oxide concentrations of about 12 wt.% but different oxide particle sizes < 001 > fiber textures parallel to the extrusion direction were observed. The observed microstructure strongly depends on the spacing of the oxide particles. With increasing spacing of the oxide particles the grain size and the fraction of Sigma 3 twins increases. Upon further isochronical annealing up to 900 degrees C no significant change of both microstructure and texture could be observed. Hence, it is concluded that the observed microstructures and textures are due to recrystallization during or immediately after the hot-extrusion process.