Phase Stability, Elastic Modulus and Elastic Anisotropy of X Doped (X = Zn, Zr and Ag) Al3Li: Insight from First-Principles Calculations

Jinzhong Tian,Shengjie Ma,Hua Hou,Yuhong Zhao

doi:10.3390/cryst12010007

Jinzhong Tian, Shengjie Ma + Show 2 more

Open Access

https://doi.org/10.3390/cryst12010007

Copy DOI

Abstract

In present work, the effects of alloying elements X (X = Zn, Zr and Ag) doping on the phase stability, elastic properties, anisotropy and Debye temperature of Al3Li were studied by the first-principles method. Results showed that pure and doped Al3Li can exist and be stable at 0 K. Zn and Ag elements preferentially occupy the Al sites and Zr elements tend to occupy the Li sites. All the Cij obey the mechanical stability criteria, indicating the mechanical stability of these compounds. The overall anisotropy decreases in the following order: Al23Li8Ag > Al3Li > Al23Li8Zn > Al24Li7Zr, which shows that the addition of Zn and Zr has a positive effect on reducing the anisotropy of Al3Li. The shear anisotropic factors for Zn and Zr doped Al3Li are very close to one, meaning that elastic moduli do not strongly depend on different shear planes. For pure and doped Al3Li phase, the transverse sound velocities νt1 and νt2 among the three directions are smaller than the longitudinal sound velocity νl. Moreover, only the addition of Zn is beneficial to increasing the ΘD of Al3Li among the three elements.

Highlights

Al-Li alloys have gained widespread attention for their use as lightweight structural materials in the aerospace field due to their low density, high elastic modulus and specific stiffness compared with other alloys [1,2,3,4]
The transverse sound velocities νt1 and νt2 among the three directions are smaller than the longitudinal sound velocity νl
We investigated the effects of alloying elements X (X = Zn, Zr and Ag) on the phase stability, elastic properties, anisotropy and Debye temperature of pure and doped Al3Li phase

Summary

Introduction

Al-Li alloys have gained widespread attention for their use as lightweight structural materials in the aerospace field due to their low density, high elastic modulus and specific stiffness compared with other alloys [1,2,3,4]. Al-Li alloys invariably possess poor ductility due to the planar slip caused by the shear of δ precipitates [8,9]. Given this situation, microalloying can improve the mechanical properties of Al-Li alloys. Our previous work studied the influence of alloying elements on the elastic properties of δ phase at higher doping concentrations [21]. Crystals 2022, 12, 7 elements on the elastic properties of δ′ phase at higher doping concentrations [21]. OOnnllyy oonnee aallllooyyiinngg aattoomm wwaass sseelleecctteedd ttoo ssuubbssttiittuuttee eeiitthheerr oonnee AAll aattoomm oorr oonnee LLii aattoomm,,aannddtthheeddooppiinnggccoonncceennttrraattiioonnooffaallllooyyiinnggeelleemmeennttiiss33.1.12255aatt..%%. TThhee BBrrooyyddeenn––FFlleettcchheerr––GGoollddffaarrbb––SShhaannnnoo ((BBFFGGSS)) wwaass sseelleecctteedd ttoo ooppttiimmiizzee wwAtdtcsprhheeihllaase3sateosspLpctssslsoecieetat,emhrcrnct5ruutoeei0etctcvmsso0nottepeuu.t5en0lserry0nwaceeet0.ttmoeVi.oow0vrp,fsfeeeeaalplpeVsrynmueeu,.dttraphsreteenaeloetadaMBnt5tnoar.hd0odie5Mlndl×.od0kBoo1uhoprn×0iipoeknl−l4rde1hoszÅd0outAo−–r.iAnsPln4F3teLalo–Å3zciProLo,k.faaianF,clmpnoelkaudrcenomrasatfdelhhleclpAeustwcuhhlcalari3eolwtLetchniciuoiAvot2alnheanl6ns3rtv2,digL×o6eteihnra2n×gael6sclne,ope2×ntdy6lhtca2iheaen×n6rlgpeletao2h-lsneway6hrldneieoaanesmlvn9hg-dewdeo×sencla9f9ldutoevs×st×mre-Xomf9c9eofundfkar×tt-xoe-smponip9moXfeaefkirdxun-egdpitmnmyAsooepiwwludrn3egLmiaatdsysiss-,

Results and Discussion

Elastic Properties

Elastic Anisotropy

Debye Temperature and Anisotropic Sound Velocities

Conclusions