Comparison of S, Pt, and Hf adsorption on NiAl(110)

Carling, Karin M.; Glover, William J.; Günaydın, Hakan; Mitchell, Tracy A.; Carter, Emily A.

doi:10.1016/j.susc.2006.02.047

Cited by 28 publications

(39 citation statements)

References 60 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Separating the binding of the representative elements of interest (e.g., Hf, Pt, and S) to the BC from their bonds to the TGO can tell us exactly why they improve (or reduce, in the case of S) adhesion: Is it because they increase binding to the BC, to the TGO, or to both? To answer this question, we compared the interface results above to our theoretical studies of adsorption of these atoms on the NiAl(110) surface (29) …”

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

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

show abstract

“…Electrons localize between the elements with the largest electronegativity difference, creating polar covalent bonds. [2] The binary NiAl(110) surface is a bcc(110) surface with two components with high-symmetry sites as possible adsorption sites, as shown in Fig. 1.…”

Section: Resultsmentioning

confidence: 99%

“…The NiAl surfaces are also used as a substrate in experimental studies of different surface phenomena such as adsorption, oxidation and formation of more complex systems. [2] Besides, the NiAl surfaces play an important role in the development of the new materials showing strong chemical reactivity against oxygen exposure. In addition, NiAl surfaces are able to form a protective oxide layer, and therefore, are used as a coating for other intermetallic alloys.…”

Section: Introductionmentioning

confidence: 99%

First‐principle studies of dissociative adsorption of H₂O on NiAl(110)‐(2 × 2) surface

Evecen

Çakmak

2010

Surface & Interface Analysis

View full text Add to dashboard Cite

show abstract

“…The design principles we have proposed may help increase the stability and hence the lifetime of TBC's in the future. We continue to explore several other dopants (Hf, Pt) and impurities (S) that are known players in the evolution of TBC's during use [5,9]. Their precise roles are unclear at present; we hope to uncover the mechanisms of their actions as part of the next phase of this research.…”

Section: Discussionmentioning

confidence: 99%

“…Thus all three elements Hf, Pt, and S are elements of interest to characterize from the standpoint of optimizing TBCs. We have undertaken a comparison of the adsorption of these three elements on NiAl(llO) [5,9]. In brief, we find that Pt and Hf prefer to bind to Ni-Ni two-fold bridge sites, consistent with STM studies by Ho and -9-coworkers, who have examined metal atom adsorption on NiAl(llO) and found that other metal atoms (they did not examine Pt or Hf) adsorb onto the Ni-Ni bridges.…”

Section: Adsorption Ofs Impurities and Hfand Pt Dopants On The Nial(1mentioning

confidence: 99%

First Principles and Multi-Scale Modeling of the Roles of Impurities and Dopants on Thermal Barrier Coating Failure

Carter¹

2007

Self Cite

View full text Add to dashboard Cite

SPONSORING / MONITORING AGENCY NAME(S) AND ADDRESS(ES)Air Force SPONSOR/MONITOR'S ACRONYM{S)APOSR/NL SPONSOR/MONITOR'S REPORT NUMBER(S)13. SUPPLEMENTARY NOTES 14. ABSTRACT Prevention or at least delay of thermal barrier coating failure is the main objective of this research, in order to increase the service lifetimes of aircraft engines. To this end, it is critical to first understand mechanisms of failure, and then use that insight to design materials countermeasures. This grant supported the following research efforts in those directions:• Developments of a new pseudopotential theory and a solid state transition path search algorithm.• Applications of first principles density functional theory to:• metal-ceramic, silicon-ceramic, and ceramic-ceramic interfaces • dopants placed between alumina and late transition metals, with implications for catalysis • fatigue in silicon and alumina • temperature hysteresis in the monoclinic-to-tetragonal phase transformation pathway for zirconia • dopants and impurities on a NiAl alloy • understanding the stability of early-late transition metal intermetallics Metal jet turbine engine components are protected by a multilayer, multi-component material known as a thermal barrier coating (TBC), comprised of a NiAl-based "bond

show abstract

Comparison of S, Pt, and Hf adsorption on NiAl(110)

Cited by 28 publications

References 60 publications

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

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

First‐principle studies of dissociative adsorption of H₂O on NiAl(110)‐(2 × 2) surface

First Principles and Multi-Scale Modeling of the Roles of Impurities and Dopants on Thermal Barrier Coating Failure

Contact Info

Product

Resources

About

Comparison of S, Pt, and Hf adsorption on NiAl(110)

Cited by 28 publications

References 60 publications

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

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

First‐principle studies of dissociative adsorption of H2O on NiAl(110)‐(2 × 2) surface

First Principles and Multi-Scale Modeling of the Roles of Impurities and Dopants on Thermal Barrier Coating Failure

Contact Info

Product

Resources

About

First‐principle studies of dissociative adsorption of H₂O on NiAl(110)‐(2 × 2) surface