摘要
Recent investigations indicated that metals can be effectively strengthened by numerous twin boundaries (TBs) with twin/matrix lamellar thicknesses in the nanometer regime.Superior strength-ductility synergies have been achieved with the nano-twin strengthening mechanism.In this talk,the novel nano-twin strengthening will be applied to austenite steels including 316L stainless steel and a Fe-Mn steel in order to optimize their strength-ductility combinations.The steels are processed by means of dynamic plastic deformation(DPD,i.e.,plastic deformation at high strain rates).Single-phased(austenite) bulk nanostructured steel specimens were prepared,consisting of nano-sized grains embedded with nano-scale twin bundles.The as-prepared nanostructured samples were annealed at various conditions,resulting in partial recrystallization of the nanostructures and forming a mixture structure of coarse-grains embedded with nano-twin bundles.Strength and ductility of the austenite steels with different amount of nano-twin bundles are analyzed.Measurements showed the nano-twin strengthen austenite steels can be superstrong (with yield strength above 1 GPa) together with a considerable ductility(elongation-to-failure >20%).
Recent investigations indicated that metals can be effectively strengthened by numerous twin boundaries (TBs) with twin/matrix lamellar thicknesses in the nanometer regime.Superior strength-ductility synergies have been achieved with the nano-twin strengthening mechanism.In this talk,the novel nano-twin strengthening will be applied to austenite steels including 316L stainless steel and a Fe-Mn steel in order to optimize their strength-ductility combinations.The steels are processed by means of dynamic plastic deformation(DPD,i.e.,plastic deformation at high strain rates).Single-phased(austenite) bulk nanostructured steel specimens were prepared,consisting of nano-sized grains embedded with nano-scale twin bundles.The as-prepared nanostructured samples were annealed at various conditions,resulting in partial recrystallization of the nanostructures and forming a mixture structure of coarse-grains embedded with nano-twin bundles.Strength and ductility of the austenite steels with different amount of nano-twin bundles are analyzed.Measurements showed the nano-twin strengthen austenite steels can be superstrong (with yield strength above 1 GPa) together with a considerable ductility(elongation-to-failure >20%).
