Eur. Phys. J. Plus (2017) 132: 190
https://doi.org/10.1140/epjp/i2017-11474-0

Regular Article

A first-principles study of structural and mechanical properties of Ti₃AlC_xN_1-x alloys

Defence Metallurgical Research Laboratory, Kanchanbagh P.O., 500058, Hyderabad, India

^* e-mail: ashishpathak@dmrl.drdo.in

Received: 1 June 2016
Accepted: 29 March 2017
Published online: 26 April 2017

Abstract

The structural stability, electronic structural and mechanical properties of ( has been investigated using the first-principles pseudopotential plane-wave method. The results for the formation energy of these compounds indicate that all the structures are stable. The equilibrium lattice constant values of Ti₃AlC and Ti₃AlN compounds are in good agreement with the experimental and theoretical data. Bonding behaviour of these alloys has been explained based on Cauchy pressure, electronic density of states and charge density. The Ti₃AlN and alloys show metallic bonding whereas Ti₃AlC and Ti₃Al display directional bonding, judged from Cauchy pressure values. All the structures satisfy the Born stability criteria in terms of elastic constants. Based on the G/B ratios, all structures are associated with ductile behaviour except Ti₃Al and Ti₃AlC which are brittle.