Embrittlement of metal by solute segregation-induced amorphization

Phys Rev Lett. 2010 Apr 16;104(15):155502. doi: 10.1103/PhysRevLett.104.155502. Epub 2010 Apr 16.


Impurities segregated to grain boundaries of a material essentially alter its fracture behavior. A prime example is sulfur segregation-induced embrittlement of nickel, where an observed relation between sulfur-induced amorphization of grain boundaries and embrittlement remains unexplained. Here, 48x10(6)-atom reactive-force-field molecular dynamics simulations provide the missing link. Namely, an order-of-magnitude reduction of grain-boundary shear strength due to amorphization, combined with tensile-strength reduction, allows the crack tip to always find an easy propagation path.