Grain boundary engineering for control of sulfur segregation-induced embrittlement in ultrafine-grained nickel

Control of brittleness associated with segregation of sulfur to grain boundaries in ultrafine-grained nickel was investigated. The brittleness could be successfully improved by controlling the grain boundary microstructure. The specimens with a higher fraction of special boundaries can have higher fracture toughness even in sulfur-bearing condition. It is evident that grain boundary engineering is applicable to controlling segregation-induced embrittlement in ultrafine-grained materials.