Melt spinning induces sub-micrometric/micrometric grained structure and dislocations in 7075 Al alloy

Abstract In an effort to further improve the strength of 7000 series commercial Al alloys relative to that of the solid-solution treated plus aged ones, the microstructure and microhardness of an as-melt spun 7075 Al alloy were studied. Our results indicate that the as-melt spun 7075 Al alloy is characterized by sub-micrometric/micrometric sized grains that contain a density of dislocations 5.7 × 10 13  m −2 , and it exhibits much higher microhardness than that of the solid-solution treated coarse-grained counterpart. The factors that affect grain size and dislocation density were analyzed and discussed. Based on the calculations of the contributions of grain boundary and dislocation strengthening to the overall strength, higher microhardness of as-melt spun 7075 Al was rationalized.