Publication Date:
2017-09-26
Description:
By means of first principles calculations, Zr-Al-C nanolaminates have been studied in the aspects of chemical bonding, elastic properties, mechanical properties, electronic structures, and vacancy stabilities. Although the investigated Zr-Al-C nanolaminates show crystallographic similarities, their predicated properties are very different. For (ZrC) n Al 3 C 2 ( n = 2, 3, 4), the Zr-C bond adjacent to the Al-C slab with the C atom intercalated in the Zr layers is the strongest, but the one with the C atom intercalated between the Zr layer and Al layer is the weakest. In contrast, the situation for (ZrC) n Al 4 C 3 ( n = 2, 3) is just the opposite. For Zr-Al-C nanolaminates, the calculated bulk, shear and Young's modulus increase in the sequence of Zr 2 AlC 〈 Zr 3 AlC 2 〈 Zr 2 Al 4 C 5 〈 Zr 3 Al 4 C 6 〈 Zr 2 Al 3 C 4 〈 Zr 3 Al 3 C 5 〈 Zr 4 Al 3 C 6 . The (ZrC) n Al 3 C 2 ( n = 2, 3, 4) series exhibit the most outstanding elastic properties. In the presence of the external pressure, the bulk and shear moduli exhibit a linear response to the pressure, except for Zr 2 AlC and Zr 3 AlC 2 , both of which belong to the so-called MAX phases. The two materials also exhibit very distinct properties in the strain-stress relationship, electronic structures and vacancy stabilities. As the intercalated Al layers increase, the formation energy of V Zr and V Al increases, while the formation energy of V C decreases. This article is protected by copyright. All rights reserved.
Print ISSN:
0002-7820
Electronic ISSN:
1551-2916
Topics:
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
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