Qu, L;
Choy, K-L;
Wheatley, R;
(2020)
Enhanced doping effects of multielement on anisotropic thermal expansion in ZrO2 with new compositions.
Journal Of The American Ceramic Society
, 103
(10)
pp. 5881-5890.
10.1111/jace.17223.
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Abstract
Coefficient of thermal expansion (CTE) of a solid material plays a critical role for a variety of high temperature applications such as thermal barrier coating (TBC) systems during the thermal cycling process. Ceramics contain ionic bonds; hence they tend to exhibit lower CTE values than alloys/metals. Developing new ceramic thermal barrier materials using promising dopants and compositions that have higher CTE values than the conventional 6‐8 wt% Y2O3 stabilized ZrO2(8YSZ) will contribute to the decrease in thermal expansion mismatch between a typical ceramic 8YSZ (10 ~ 11 × 10−6°C−1) top coat and a metal alloy based bond coat such as NiCrAlY (14 ~ 17×10−6°C−1, Padture et al., Science, 2002;296:280–4; Liang et al., J Mater Sci Technol, 2011;27(5):408–14), which is highly desirable. This work reports design, modeling, synthesis, and characterization of promising new compositions based on Dy3+, Al3+, and Ce4+‐doped YSZ that consist of the tetragonal structure and have an enhanced thermal expansion than 8YSZ. The intrinsic CTE at the atomic level has been investigated via molecular dynamics (MD) simulation. The atomic scale analysis provides new insights into the enhanced doping effects of multiple trivalent and tetravalent cations on the lattice structure, lattice energy, and thermal expansion in ZrO2. The calculated lattice energy becomes smaller with the incorporation of Dy3+, Al3+, and Ce4+ions, which corresponds strongly to the increase in CTE. The crystalline size is reduced due to the incorporation of the Al3+ and Ce4+, whereas the sintering resistance is enhanced ascribed to the addition of Dy3+ and Al3+. Doping Dy3+, Al3+, and Ce4+ cations to YSZ increased the CTE value of YSZ and for Dy0.03Y0.075Zr0.895O1.948, the CTE is 12.494 × 10−6°C−1 at 900°C, which has an 11% increase, as compared with that of 8YSZ.
| Type: | Article |
|---|---|
| Title: | Enhanced doping effects of multielement on anisotropic thermal expansion in ZrO2 with new compositions |
| Open access status: | An open access version is available from UCL Discovery |
| DOI: | 10.1111/jace.17223 |
| Publisher version: | https://doi.org/10.1111/jace.17223 |
| Language: | English |
| Additional information: | This version is the author accepted manuscript. For information on re-use, please refer to the publisher’s terms and conditions. |
| Keywords: | Coefficient of thermal expansion; lattice structure; molecular dynamics simulation; new thermal barrier materials |
| UCL classification: | UCL UCL > Provost and Vice Provost Offices > UCL BEAMS UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Maths and Physical Sciences UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Maths and Physical Sciences > MAPS Faculty Office UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Maths and Physical Sciences > MAPS Faculty Office > Institute for Materials Discovery |
| URI: | https://discovery.ucl.ac.uk/id/eprint/10107771 |
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