Assessment of Boron Diffusivities in Nickel Borides by Two Mathematical Approaches

Mourad Keddam; Peter Jurči

doi:10.3390/ma15020555

Assessment of Boron Diffusivities in Nickel Borides by Two Mathematical Approaches

Materials (Basel). 2022 Jan 12;15(2):555. doi: 10.3390/ma15020555.

Authors

Mourad Keddam¹, Peter Jurči²

Affiliations

¹ Laboratoire de Technologie des Matériaux, Faculté de Génie Mécanique et Génie des Procédés, Université des Sciences et de la Technologie Houari-Boumediene, B.P N°32, El-Alia, Bab-Ezzouar, Algiers 16111, Algeria.
² Department of Materials Science, Faculty of Material Sciences and Technology in Trnava, Slovak University of Technology, J. Bottu 25, 91724 Trnava, Slovakia.

Abstract

In the work of this contribution, two kinetics models have been employed to assess the boron diffusivities in nickel borides in case of Inconel 718 alloy. The first approach, named the alternative diffusion model (ADM), used the modified version of mass conservation equations for a three-phase system whilst the second one employed the mean diffusion coefficient (MDC) method. The boron diffusivities in nickel borides were firstly evaluated in the interval of 1123 to 1223 K for an upper boron concentration of 11.654 wt% in Ni₄B₃. The boron activation energies in the three phases (Ni₄B₃, Ni₂B and Ni₃B) were secondly deduced by fitting the values of boron diffusivities with Arrhenius relations. Finally, these values of energy were compared with the results from the literature for their experimental validation.

Keywords: MDC method; activation energy; alternative diffusion model (ADM); boronizing; kinetics; nickel borides.