Kinetic competitivity between ordering and solute segregation to dislocations in Cu-20% at. Mn

Abstract

By using differential scanning calorimetry (DSC), energetic measurements associated with the different peaks displayed during linear heating of Cu-20 % at. Mn were made, employing quenched and cold-worked materials. Unlike to the situation observed in the quenched alloy in which disperse order is developed, in the deformed alloy such process is inhibited by the segregation of solute atoms to partial dislocations. An appropriate model for calculating the energy evolved during the pinning process was applied in order to determine the dislocation density from the exothermic peak designated as stage 4. The computed value, which is in excellent agreement with the one obtained from expressions governing the energy release accompanying recrystallization, allows to verify together with microhardness measurements and kinetic analysis that the first observed thermal effect in the deformed material effectively corresponds to a solute segregation process.