Probing the Activation Migration Enthalpies of Dislocations in 2024 Aircraft Material Using Nuclear and Electrical Techniques

Abstract

Positron annihilation lifetime (PAL) measurement is one of the most important nuclear techniques used in materials science. Electrical measurements are also used in materials science. Both PAL and electrical measurements were used here to determine the activation energy of migration of dislocations in one of the most important engineering aluminum alloys: 2024. Samples of 25% deformed (thickness reduction) material have been used for these studies. The isothermal annealing measurements were performed at 583, 603, 623 and 643K for both techniques. The activation energy of migration of the dislocation was found to be equal to 1.24 ± 0.08eV by using PAL measurements and to 1.35 ± 0.01eV by using the electrical technique.

A Study of the Effect of Natural Aging on Some Plastically Deformed Aluminum Alloys Using Two Different Techniques

“…The potential difference, V and current, I, were determined using a digital multimeter. The electrical resistivity, ρ, of the samples was calculated according to [2][3][4][5][6][7][8][9][10]:…”

Effect of Ageing on Microstructures, Electrical Properties and PALS of Aircraft Al Alloy 2024

“…Characterizing the resistivity of aluminum alloys requires the measurement of very low resistances (and therefore, low voltages) accurately. The techniques described here can also be used in applications involving other small voltage measurements, such as those needed in measuring the resistance of superconductors, nanowires, carbon nanotubes, graphene (a one-atom-thick form of carbon), and other nanomaterials in which applied power must be kept low to prevent material heating [5,6]. Imagine a conductive material sample in the shape of a thin block with thickness t, width w, and some arbitrary length.…”