Dopant segregation and embrittlement at Mo grain boundaries

Richard Tran and Zihan Xu published their paper on “Computational study of metallic dopant segregation and embrittlement at Molybdenum grain boundaries” in Acta Materialia. Mo and its alloys are important refractory materials for high temperature applications, but suffer from low ductility. In this work, we investigated the segregation and strengthening effects of 29 metallic dopants using DFT and empirical continuum models. We show that dopant chemistry and site preference plays a significant role in segregation behavior and strengthening effects at the GBs that deviate from simple bond-breaking arguments. Ta, Re, Os and W are predicted to have a weak strengthening effect on Mo for the Σ5(310) tilt GB, and Mn, Fe, Co and Nb are predicted to have reasonable strengthening effects for the Σ5(100) twist GB. Check out the paper at our publications page.