TEM Observations on the Evolution of Grain Structure in Pressurized Al-0.5Cu Thin Films

Abstract

This paper reports the observations of the grain-refining mechanism found in Al-0.5Cu thin films that are subjected to hydrostatic compressive pressure during the annealing process. The films are deposited on Si substrates and subsequently placed under 60 MPa Ar gas pressure at 400°C. Transmission electron microscopy on these films reveals that plastic deformation occurs by dislocation slip and induces a refined grain structure. Polygonization is the primary mechanism for grain refining, resulting in the formation of sub-grain boundaries.