Prediction of double transition metal (Cr_1−xZr_x)₂AlC MAX phases as thermal barrier coatings: Insight from density functional theory

Abstract

Herein, a high purity (Cr 1Àx Zr x ) 2 AlC solid solutions (with x = 0-1) have been investigated intensively using the first principles density functional theory calculations. The optimized structural parameters were founded to be in good agreement with the experimental results, and increased steadily with rising Zr in (Cr 1Àx Zr x ) 2 AlC solid solutions. The elastic constants C ij and enthalpy formation have been calculated and firmly confirmed that these solid solutions were mechanically and thermodynamically stable. Moreover, the mechanical properties show that the compounds possess brittle behavior with covalent bonding signified that they are relatively hard compared to other MAX phases. Further, the electronic band structures were studied and found a metallic behavior for all the investigated concentrations. Consequently, all the compositions of solid solutions were identified as promising materials for thermal barrier coating and high temperature structural materials due to the high value of melting temperatures and low minimum thermal conductivity.

First-principles calculations to investigate physical properties of orthorhombic perovskite YBO3 (B = Ti & Fe) for high energy applications

“…Furthermore, the ground-state physical properties of Pb(Mg 1/ 3 Nb 2/3 )O 3 compounds are predicted to be the most tolerant material for thermal barrier coating. 19 Numerous studies reported the halides and oxides perovskites and MAX phase which possesses the physical, mechanical, and chemical properties because of the potential applications in various elds, [4][5][6][7][20][21][22] and it is observed that our investigated results, show consistency with the available results in the literature. So, this class of materials perovskite oxides promising applications for enlightening properties for various technologically equipped societies.…”

“…For both YTiO 3 and YFeO 3 compounds the T m (melting temperature) is calculated using the following expression. 18,19,21,22,48…”

DFT insights into i-MAB phase, Mo4Y2Al3B6: a potential thermal barrier coating and solar heat reducing material

“…In the above equations, v m is the average sound velocity which is calculated from longitudinal (v l ) and transverse (v t ) sound velocities, respectively, r is the mass density, N A is Avogadro's number, M is the molar mass, n is the number of atoms in the unit cell, K B is the Boltzmann's constant and h is the Planck's constant. The calculated Debye temperature is 627 K which is relatable with other promising compounds [95,96]. Table 6 illustrates that the Θ D value of the compound under study is less than that of the Ti 2 PB 2 compound, possibly because of the lower stiffness constant of Mo 4 Y 2 Al 3 B 6 compared to Ti 2 PB 2 (refer to table 2).…”