Effect of Noble Metal Addition on the Disorder Dynamics of Ni3Al by Means of Monte Carlo Simulation

J.J Ramos-Hernandez,C.D Arrieta-Gonzalez,G.K Pedraza-Basulto,M Sanchez-Carrillo,J.P Flores-De Los Rios,E Porcayo-Palafox,S.E Diaz-Mendez,J.G Chacon-Nava,J Porcayo-Calderon

doi:10.3390/ma13214832

J.J Ramos-Hernandez, C.D Arrieta-Gonzalez + Show 7 more

Open Access

https://doi.org/10.3390/ma13214832

Copy DOI

Abstract

In this work, the effect of the addition of noble metals on the order–order disorder process of the L12 structure corresponding to the intermetallic Ni3Al is analyzed. Stoichiometric, nonstoichiometric, and quasi-binary compositions doped with noble metals such as Ag, Au, Pd, and Pt (1 at%) were analyzed. It was observed that depending on the composition, there is a modification in the activation energies calculated from the two time constants that characterize the disorder process. The statistic of atomic jumps was typified based on the configuration of the window to be crossed and, with this, it was identified that the origin of the negative activation energy of the long disorder process is due to an increase in the corresponding energy of the AlAl-Ni jump through unnatural windows.

Highlights

Nickel aluminides, such as NiAl and Ni3 Al, are potential materials for high-temperature structural applications
This study reports the results of the Monte Carlo simulation of the relaxation mechanism of the L12 superstructure disorder due to the variation in its composition and noble metal doping
Nonstoichiometric and noble metal-doped formulations show a change in activation energy in the short and long disorder processes, which implies a variation in the energy of the jumps that generate disorder

Summary

Introduction

Nickel aluminides, such as NiAl and Ni3 Al, are potential materials for high-temperature structural applications. The Ni3 Al lattice structure can be visualized as four interpenetrated sub-lattices, the atomic distribution of which is such that each atom is surrounded by 12 atoms that make up the first coordination layer commonly called near neighbors (NN). The interpenetrated sub-lattices can be visualized, the atoms corresponding to the Al sub-lattice are identified with the letter A and those of Ni with the letters B, C and D. For Ni atoms, the first coordination layer consists of eight. Ni and four Al atoms, while for Al atoms, the coordination layer consists of only Ni atoms. Another important characteristic is that they form a combination of layers with different compositions, one of

Methods

Results

Conclusion