Sazol Kumar Das

Erratum to: Anisotropic Diffusion Behavior of Al in Mg: Diffusion Couple Study Using Mg Single Crystal

IN the calculation of the interdiffusion coefficients of two intermediate phases and the impurity diffusion coefficients ofAl in hcpMg, a small numerical errorwas found. The error does not change the main conclusions of the work but can lead to small errors in the diffusion calculations. The following is a revision of the interdiffusion coefficients and impurity diffusion coefficient. The numbering of figures, tables and references used in this erratum are the same as the original paper for convenience. Interdiffusion coefficients for two intermediate phases (Mg17Al12 and Mg2Al3) were calculated using the Heuman-Matano method by identifying the Matano plane from Al concentration profile throughout the whole diffusion zone quantified by Electron Probe Micro Analyzer (EPMA). For example, the position of the Matano plane for the sample annealed after 72 hours at 693 K (420 C) is marked in Figure 1. The revised interdiffusion coefficients for the Mg17Al12 and Mg2Al3 intermediate phases are presented in Table III and in Figure 4 with comparison to previous studies. Our results are in good agreement with Brennan et al. The revised values for the Al impurity diffusion coefficient in hcp Mg from the multiphase diffusion calculation used in the original paper are plotted in Figure 7(a). In order to confirm the impurity diffusion, a Gaussian solution of Fick’s second law is also applied to analytically calculate impurity diffusion coefficient in this erratum. In the analytical method, the impurity diffusion coefficient for each sample was calculated from the slope of ln (Al concentration) vs square of penetration distance in dilute Al concentration region of hcp Mg solid solution. As can be seen in Figure 7(a), the analytical results are in good agreement with the results obtained from multiphase diffusion simulation. The revised Al impurity diffusion coefficients, depending on the orientation of hcp Mg, were plotted in Figure 7(b) and compared with previous studies. The revised optimized mobilities of Al in hcp Mg along the aand c-axis of Mg crystal are

Anisotropic Diffusion Behaviour of Al and Zn in HCP Mg: Diffusion Couple Experiment Using Mg Single Crystal

Diffusion couple experiments for Mg-Al and Mg-Zn were carried out with Mg single crystal to determine the anisotropic diffusion coefficients of Al and Zn in hcp Mg at the temperature range between 553 and 693 K. Based on the experimental results, anisotropic diffusion coefficients of Al and Zn were calculated using multiphase diffusion simulations. Al diffusion in hcp Mg is slightly faster than Mg self-diffusion itself, but the diffusion of Zn is slightly slower than Mg self-diffusion. The diffusion coefficients of Al and Zn along the a-axis (basal plane) of hcp Mg is slightly higher (1.1-1.4 times) than those along the c-axis (normal to the basal plane), which is also similar to Mg self-diffusion behaviour.

Multiphase Diffusion Study for Mg-Al Binary Alloy System

Multiphase diffusion simulation and annealing experiments have been performed for Mg-Al binary alloys at various temperatures. Annealing experiments of Mg-3wt% Al and Mg-6wt% Al alloys were carried out at 330 and 400 °C for various times and the change of concentration profiles of Al in grains were measured by Electron Probe Micro Analyzer (EPMA). In order to simulate this annealing process and understand the diffusion of Mg-Al alloys, diffusion model was developed by using Finite Difference Method (FDM) coded in FORTRAN. In the diffusion simulations, composition-independent inter-diffusion coefficients were used and the intermetallic phases were assumed to have equilibrium compositions.