TY - JOUR
T1 - Disorder-induced melting in nickel
T2 - Implication to intergranular sulfur embrittlement
AU - Heuer, J. K.
AU - Okamoto, P. R.
AU - Lam, N. Q.
AU - Stubbins, J. F.
N1 - This work was supported by the US Department of Energy, Office of Science, under contract W-31-109-Eng-38. Ion implantation and backscattering experiments were performed at the HVEM Tandem Accelerator Facility at Argonne National Laboratory with extensive help from P.M. Baldo, L.L. Funk, and A.W. McCormick. Slow-strain-rate tensile tests were performed using the Stress Corrosion Cracking facilities at Argonne National Laboratory with the assistance of H.M. Chung, D.R. Perkins, and W.E. Ruther. Auger electron spectroscopy was performed at the Center for Microanalysis of Materials at the University of Illinois with guidance from N. Finnegan. Special thanks are extended to B.J. Kestel for aid with specimen preparation.
PY - 2002/3
Y1 - 2002/3
N2 - Why and how sulfur segregation leads to intergranular embrittlement of nickel has been investigated by a combination of Auger electron spectroscopy, slow-strain-rate tensile tests, ion-implantation, and Rutherford backscattering spectrometry studies. Grain-boundary sulfur concentrations in dilute Ni-S alloys were systematically varied by time-controlled annealing of specimens at 625 °C. The critical sulfur concentration for 50% intergranular fracture of 15.5±3.4 at.% S was found to be, within experimental error, equal to the critical implant concentration of 14.2±3.3 at.% S required to induce 50% amorphization of single-crystal nickel during S+ implantation at liquid nitrogen temperature. This suggests that segregation-induced intergranular embrittlement, like implantation-induced amorphization, may be a disorder-induced melting process, albeit one occurring locally at grain boundaries. In addition, a kinetic model for segregation-induced embrittlement based on Poisson statistics is introduced, and the synergistic effects of hydrogen-sulfur co-segregation on embrittlement are discussed.
AB - Why and how sulfur segregation leads to intergranular embrittlement of nickel has been investigated by a combination of Auger electron spectroscopy, slow-strain-rate tensile tests, ion-implantation, and Rutherford backscattering spectrometry studies. Grain-boundary sulfur concentrations in dilute Ni-S alloys were systematically varied by time-controlled annealing of specimens at 625 °C. The critical sulfur concentration for 50% intergranular fracture of 15.5±3.4 at.% S was found to be, within experimental error, equal to the critical implant concentration of 14.2±3.3 at.% S required to induce 50% amorphization of single-crystal nickel during S+ implantation at liquid nitrogen temperature. This suggests that segregation-induced intergranular embrittlement, like implantation-induced amorphization, may be a disorder-induced melting process, albeit one occurring locally at grain boundaries. In addition, a kinetic model for segregation-induced embrittlement based on Poisson statistics is introduced, and the synergistic effects of hydrogen-sulfur co-segregation on embrittlement are discussed.
UR - https://www.scopus.com/pages/publications/0036498664
UR - https://www.scopus.com/pages/publications/0036498664#tab=citedBy
U2 - 10.1016/S0022-3115(02)00707-9
DO - 10.1016/S0022-3115(02)00707-9
M3 - Article
AN - SCOPUS:0036498664
SN - 0022-3115
VL - 301
SP - 129
EP - 141
JO - Journal of Nuclear Materials
JF - Journal of Nuclear Materials
IS - 2-3
ER -