Auger electron spectroscopy study of the kinetics of intergranular and surface segregations in nickel during annealing

Quantitative grain boundary analysis of bulk samples by SIMS

“…The line is the Langmuir-McLean expression with a segregation free energy of À97.8 kJ mol À1 and a saturation grain boundary concentration of 28.0 ng cm À2 . be converted to~0.46 of a monolayer in very good agreement with values determined by Larère et al (X Max = 0.44) [1] and by Lejcek et al (X Max = 0.40). [12]…”

“…We have analysed these data using the well-known Langmuir-McLean formalism and obtained a free energy of equilibrium segregation, ΔG, of À97.8 kJ mol -1 and a saturation level of m Max = 28.0 ng cm À2 , which corresponds to a saturation concentration of sulphur atoms to an average grain boundary N Max = 5.27 Â 10 14 atoms cm À2 . The ΔG value determined in this work is in excellent agreement with the value estimated by Larère et al from AES analysis (À98 kJ mol -1 at 750 C), [1] and the saturation concentration can [1] and by Lejcek et al (X Max = 0.40). [12] …”

“…For example, sulphur is known to strongly embrittle nickel alloys. [1,2] Grain boundary segregation has been extensively studied over the last 40 years, mainly using Auger electron spectroscopy (AES). [3] The conventional route for AES analysis of grain boundaries is to fracture the sample in an ultrahigh vacuum and then to analyse the fracture surface.…”

Microstructural characterization of INCOLOY 903 weldments

“…As can be observed, phosphorus is the dominant segregating element in iron-base alloys containing phosphorus. Similarly, Larere et al [159] have shown that sulphur and phosphorussegregate to free surfaces in nickel, whereas park et al' [160] have shown grain boundary segregation of P and S in 304 stainless steel using Auger spectroscopy.…”

The deuterium-impurity interaction and the grain boundary embrittlement in nickel

“…A comparison of the sulphur, carbon, and hydrogen segregation energies, -138 < -46 < -4.5 kJ/mol confirmed the correctness of the assumption of a stable segregation structure during hydrogen (protonium or deuterium) segregation. It is interesting to compare the obtained data with those described in [2] where grain boundaries of nickel doped with molybdenum were investigated. As molybdenum efficiently stabilizes carbon in the grain bulk, certain discrepancies in the carbon segregation features can be expected in comparison with our work.…”