First-principles characterization of a heteroceramic interface:<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:msub><mml:mrow><mml:mi mathvariant="normal">ZrO</mml:mi></mml:mrow><mml:mrow><mml:mn>2</mml:mn></mml:mrow></mml:msub></mml:mrow><mml:mn /><mml:mo>(</mml:mo><mml:mn>001</mml:mn><mml:mo>)</mml:mo><mml:mn /></mml:math>deposited on an<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mi>α</mml:mi><mml:mo>−</mml:mo><mml:mrow><mml:msub

Christensen, Asbjørn; Carter, Emily A.

doi:10.1103/physrevb.62.16968

Cited by 65 publications

(33 citation statements)

References 68 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Generally the GGA overcorrects the LSDA underestimation of experimental structural energy differences. This was also noted in our previous work on the ZrO 2 (001)/␣-Al 2 O 3 (11 02) interface, 18 using the so-called PB parameterization 35,55,56 of the GGA. As with structural properties, we find that O I ͑soft͒ is just as transferable as O II ͑hard͒ for relative energetics.…”

Section: The Bulk Phases Of Zro 2 and Nisupporting

confidence: 75%

See 1 more Smart Citation

Adhesion of ultrathin ZrO2(111) films on Ni(111) from first principles

Christensen¹,

Carter

2001

The Journal of Chemical Physics

Self Cite

117

View full text Add to dashboard Cite

We have studied the ZrO 2 ͑111͒/Ni͑111͒ interface using the ultrasoft pseudopotential formalism within density functional theory. We find that ZrO 2 (111) adheres relatively strongly at the monolayer level but thicker ceramic films interact weakly with the Ni-substrate. We argue that the cohesion changes character from dominantly image charge interactions for thick ceramic films to more covalent for monolayer ZrO 2 (111) films. We provide an analysis of energetic, structural and electronic aspects of the ZrO 2 /Ni interface as a function of the thickness of the oxide layer. We also address the role of the exchange-correlation density functional parameterization for modeling the oxide and metal/oxide interface and discuss the sensitivity of the supercell approximation for metal/oxide interface properties.

show abstract

Section: The Bulk Phases Of Zro 2 and Nisupporting

confidence: 75%

“…Further, the ceramic system releases the tensile stress by transformation to a pseudo m-ZrO 2 phase. In other recent work, 18 we found that thin c-ZrO 2 (001) films transformed to m-ZrO 2 (001), even without an imposed strain in the ceramic layer.…”

Section: Interface Cohesionsupporting

confidence: 56%

Adhesion of ultrathin ZrO2(111) films on Ni(111) from first principles

Christensen¹,

Carter

2001

The Journal of Chemical Physics

Self Cite

117

View full text Add to dashboard Cite

show abstract

“…In this regard we note that calculations indicate that the zirconia/alumina bond is relatively weak [40], [3]. Further, we note that zirconia has monoclinic, tetragonal, and cubic crystal forms.…”

Section: Interfacial Chemistrymentioning

confidence: 72%

Theory and modeling of active brazing.

Swol¹,

Miller²,

Lechman³

et al. 2013

View full text Add to dashboard Cite

Active brazes have been used for many years to produce bonds between metal and ceramic objects. By including a relatively small of a reactive additive to the braze one seeks to improve the wetting and spreading behavior of the braze. The additive modifies the substrate, either by a chemical surface reaction or possibly by alloying. By its nature, the joining process with active brazes is a complex nonequilibrium non-steady state process that couples chemical reaction, reactant and product diffusion to the rheology and wetting behavior of the braze. Most of the these subprocesses are taking place in the interfacial region, most are difficult to access by experiment. To improve the control over the brazing process, one requires a better understanding of the melting of the active braze, rate of the chemical reaction, reactant and product diffusion rates, nonequilibrium 3 composition-dependent surface tension as well as the viscosity. This report identifies ways in which modeling and theory can assist in improving our understanding. 4 AcknowledgmentThanks to Allen Roach and Carlton Brooks for stimulating discussions of active brazes and surface tensions of metals. The ASC-PEM project is gratefully acknowledged for providing funding. 5This page intentionally left blank.

show abstract

“…Early on we evaluated the work of separation (W sep ) for bulk zirconia phases (13) and α-Al 2 O 3 (14), as well as for models of the relevant heterogeneous interfaces, YSZ/TGO (15) and TGO/BC (16,17). This series of calculations quantified that the weak links are the interfaces, with the latter being weakest of all.…”

Section: Resultsmentioning

confidence: 99%

“…The oxygen anions only destabilized the interface. By contrast, the LDOS of ZrO 2 show significant 4d occupation, which suggests that the O anions in zirconia are more like O − than O 2− , i.e., the oxygen atoms have a partially open 2p shell that permits covalent bonding at interfaces (15). YSZ/Ni superalloy interfaces were also modeled (18); the more covalent zirconia indeed formed stronger bonds to Ni (W sep ∼ 1 J∕m 2 ) than the ionic alumina.…”

Section: Resultsmentioning

confidence: 99%

Atomic-scale insight and design principles for turbine engine thermal barrier coatings from theory

Marino

Hinnemann

Carter

2011

Proc. Natl. Acad. Sci. U.S.A.

Self Cite

View full text Add to dashboard Cite

To maximize energy efficiency, gas turbine engines used in airplanes and for power generation operate at very high temperatures, even above the melting point of the metal alloys from which they are comprised. This feat is accomplished in part via the deposition of a multilayer, multicomponent thermal barrier coating (TBC), which lasts up to approximately 40,000 h before failing. Understanding failure mechanisms can aid in designing circumvention strategies. We review results of quantum mechanics calculations used to test hypotheses about impurities that harm TBCs and transition metal (TM) additives that render TBCs more robust. In particular, we discovered a number of roles that Pt and early TMs such as Hf and Y additives play in extending the lifetime of TBCs. Fundamental insight into the nature of the bonding created by such additives and its effect on high-temperature evolution of the TBCs led to design principles that can be used to create materials for even more efficient engines.A ircraft and power plants share a common source of usable energy: Both employ turbine engines that combust fuel to either propel airplanes or produce electricity. At a time in which efficient use of energy is paramount, improving the efficiency of turbine engines is one means to contribute to this global challenge. Turbine engines operate via the Brayton cycle, which offers lower carbon dioxide emissions and lower cost for power generation than other possible alternatives. Their efficiency can be increased by increasing the inlet temperature, which allows more expansion of gas that creates more pressure to drive the turbine. However, high-temperature operation, under oxidizing conditions, poses serious demands on the materials used to construct jet engine components. Materials must be found that are robust under such harsh operating conditions. Engineers over the past few decades have improved greatly the thermomechanical properties of the metal alloy comprising, e.g., the turbine blades, and have created a multilayer coating for the blades that protects against both heat and corrosion, referred to as a thermal barrier coating (TBC). These materials advances, along with internal component cooling, have been astonishingly successful, allowing the gas temperature to exceed the melting point of the metal alloy from which the engine components are constructed! Despite these advances, more robust TBCs are desired, either to extend TBC service lifetime under present-day operating conditions or to operate at even higher temperatures to achieve more efficient energy conversion. As a result, characterization and optimization of TBC properties have continued to be active areas of research. As is the case for most materials development, the usual path to improve TBCs relies on trial and error. Many materials compositions are fabricated, characterized, and tested. Unfortunately, characterization typically is performed postmortem, as virtually no instruments exist to characterize a TBC in situ during operation. The lack of in situ probes makes...

show abstract

First-principles characterization of a heteroceramic interface:ZrO2(001)deposited on anα−

Cited by 65 publications

References 68 publications

Adhesion of ultrathin ZrO2(111) films on Ni(111) from first principles

Adhesion of ultrathin ZrO2(111) films on Ni(111) from first principles

Theory and modeling of active brazing.

Atomic-scale insight and design principles for turbine engine thermal barrier coatings from theory

Contact Info

Product

Resources

About