GRAIN GROWTH AND RECRYSTALLIZATION IN TITANIUM AND ITS ALLOYS PART I Excessive Grain Coarsening PART II Grain Growth and Recrystallization Studies

摘要

Both commercial purity sponge titanium (RC-55) and the 02-N2 alloy (Ti-100A) when cold worked and annealed exhibit excessive grain coarsening in which a maximum average grain size is developed when annealing follows a critical amount of cold work, and prior to deformation grain size are shown to have an extensive influence on final grain size.nThe alpha-beta alloys (Ti-150A and RC-130A0 do not permit a grain size measurement and those minor microstructural changes observed after cold working and annealing appear to be principally of thermal origin and little influenced by the magnitude of prior cold working.nThe large grain size occasioned by annealing RC-55 after a critical amount of cold rolling is attributable to strain induced boundary migration and not to growth of nuclei or sub-structure