The Research On Structure And Thermal Properties Of Zr-In,Zr-Si And Zr-Cu Intermetallic Compounds:A First-principle Calculations

In this paper,the first-principle calculations were applied to investigate the structures and properties of Zr-In,Zr-Si and ZrCu-based intermetallic compounds.(1)The mechanical properties,including bulk modulus(B),shear modulus(G),Young’s modulus(E)and hardness(H),thermal properties arid electronic structures of the InZr3,InZr,In2Zr,α-In3Zr intermetallic compound have been investigated using a first principle calculation.The connection between the concentration of the In atom and the mechanical and thermal properties has been further explored.(2)The mechanical and thermal properties of a-ZrSi,Zr5Si3,Zr3Si2,β-ZrSi,Zr2Si and ZrSi2 compounds were carefully discussed and analyzed.Anisotropy of elasticity and thermal conductivity were discussed.The research shows that all the Zr-Si compounds in this paper display the anisotropy.The bulk anisotropy and the shear anisotropy are weak for all the compounds.The shear anisotropy strongly depends on the direction.(3)The influence of the TM(TM=Ru,Rh,Pd)elements on B2-ZrCu parent has been investigated using a first-principle calculation.The results of the formation enthalpies show that the TM(TM=Ru,Rh,Pd)elements prefer to occupy the Cu atom sites.The calculated results of the substitutional formation energy indicate that the distribution trend of the dopants in B2-ZrCu phase is Ru>Rh>Pd below the dopant concentration 9 at.%and the distribution trend is Rh>Pd>Ru from 9 at.%to 12.5 at.%.The influence of TM(TM=Ru,Rh,Pd)elements on mechanical properties,thermal properties and martensitic transformation were discussed.The addition of Ru and Rh elements is able to improve the bulk modulus(B)and shear modulus(G)but weaken the ductility.Compared with Rh and Pd element,the Ru element is of the best strengthen effect.The prediction for martensitic transformation temperature suggests that the addition of 6.25 at.%Pd is able to improve the martensitic transformation temperature.The other transition metal elements(Ru and Rh)and higher concentration of Pd incorporation will cause the martensitic transformation temperature to decline.The addition of TM elements improves the melting point.(4)A first-principle calculation was applied to investigate the distribution mode of the light B atoms at B2-ZrCu systems.When the B concentration is lower than 5.882 at.%,the B atoms either locate in the octahedral interstices in the<110>direction to form corresponding interstitial compounds or replace the Cu atoms to form the relevant substitution solid solution.When the B content is higher than 5.882 at.%,it can only replace the Cu atoms and form the substitution solid solution.The effect of the B atoms on mechanical properties and thermal properties has been analyzed.The analysis of electronic structure reveal the nature of the changing of mechanical properties.