Published online by Cambridge University Press: 01 January 1992
Equilibrium grain boundary segregation at symmetrical <110> tilt grain boundaries of Ni3AI bicrystals containing 0.17 at% B and traces of S has been studied by Auger electron spectroscopy and compared directly to surface segregation by applying a special specimen geometry. From the experimentally determined interfacial concentrations after annealing at different temperatures, segregation free energies for B and S at both types of interfaces have been determined using the Langmuir-McLean equation. The effect of B and S segregation on the grain boundary cohesive energy has been calculated.