Modelling solute segregation to partial dislocations for DSC evaluations

Abstract

A general model is discussed for assessing the energy release due to the pinning of solute atoms to partial dislocations. The present approach discloses the influence of dislocation character distributions on the magnitude of this energy. In order to test its validity in ctCu-Al alloys, differential scanning calorimetry (DSC) evaluations associated with the different peaks involved during linear heating were performed employing both cold worked and quenched materials. Dislocation densities were calculated from recrystallization traces. On the basis of this model it was concluded that the observed energy difference between the deformed and the quenched materials during the exothermic peak designated as Stage 2 corresponds to the pinning process. It was also concluded that nearly equal number of edge and screw dislocations are present in the dislocation configuration of deformed alloys. Nevertheless, it is proposed that dislocation-induced order might also occur as a consequence of enhanced solute concentration around the partials.

Correlation between the temperature dependence of yield stress and the nature of solute distribution in Cu–Ni solid solutions

“…This is true for both solid-solution as well as nominally pure element crystals. For instance, solute segregation to partial dislocations [2][3][4][5] and stacking faults [6] as well as local ordering (whether short-range order or clustering) of solute atoms [7][8][9] in single-phase binary and ternary alloys play an important role in this regard. So is the case with the nominally pure metals [10][11][12] in which migration of point defects, e.g.…”

“…The physical, functional, electrical and mechanical properties of crystalline materials are closely linked to the microstructural developments [1][2][3][4][5][6][7][8][9][10][11] which occur in the lattice. This is true for both solid-solution as well as nominally pure element crystals.…”

Efeito do teor residual de Fe no recozimento do latão 70/30.

“…Ressalta-se a amostra CuZn-6Fe, com maior teor de ferro, para a qual o tempo de recozimento não resultou em crescimento de grão para o tratamento a 500ºC. (IZUMI, 1966;DUBLEK et al, 1979, MIGSCHITZ et al, 1996, SPANL et al, 1997, SPANL et al, 1999DONOSO, E., 1997 • foram utilizados dados de módulo de cisalhamento, raios atômicos, parâmetro de rede e vetor de Burgers obtidos à temperatura ambiente.…”