Published online by Cambridge University Press: 26 February 2011
A computer calorimetry technique employing molecular dynamics simulation has been used to calculate formation free energies for a copper impurity atom in a perfect nickel crystal in which the atoms are interacting through embedded-atom potentials. The method has also been used to calculate segregation free energies for a copper impurity at different site of a Σ=5 (031)[100] symmetical tilt boundary in nickel. Comparison of energetic and entropic contributions to segregation free energies indicate that knowledge of the entropic contribution is essential for prediciton of impurity site selection at grain boundaries above room temperatures.