BOUTASSOUNA Djamal University of Laghouat

An Attempt for the Estimation of the Sulfur Segregation Energy for the Grain Boundary Segregation in Nickel

Co-authors LE GALL René, LEFKAIER Ibn Khaldoun

Quantitative AES analysis of sulfur in the grain boundaries of a metallic Nickel based system having composition of 0.8 mass ppm sulfur in the range 650–850°C, unveils that only samples annealed at 650 °C show existence of sulfur in their grain boundaries. The obtained average grain boundary composition at this temperature is calculated approximately to 15.08 % atomic of sulfur. Considering the model of Guttmann, Gibbs’s free energy of segregation is expressed as GS=2+G0, where  is the interaction parameter (negative sign for attractive interaction). For the studied Ni(S) system we estimate GS to – 154.18 kJ/mol, and If we chose the value of =-27 kJ/mol for our calculations, we obtain G0 = -105 kJ/mol which is relatively close to that found in other works.

Back