In situ Al_3Ti and A1_2O_3 nanoparticles reinforced Al composites produced by friction stir processing in an Al-TiO_2 system

摘要

Al and TiO_2 powders were selected to fabricate in situ Al composites via multiple pass friction stir processing (FSP) based on the thermodynamic analysis. The microstructural investigations indicated FSP would induce reaction between Al and TiO_2. Al_3Ti and A1_2O_3 particles were formed after 4 pass FSP with 100% overlapping. The in situ particles were about 80 nm in size at various FSP conditions, and ultrafine matrix grains 602 nm in size were obtained when water cooling was applied during FSP. Tensile tests indicated that the in situ nanocomposites exhibited pronounced work hardening behavior and a good combination of strength and ductility.