Thermophysical properties of lanthanum zirconate coating prepared by plasma spraying and the influence of post-annealing

Chen, Hongfei; Gao, Yanfeng; Tao, Shunyan; Liu, Yun; Luo, Hongjie

doi:10.1016/j.jallcom.2009.06.162

Cited by 79 publications

(37 citation statements)

References 35 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…[35] reported thermal conductivities of 0.73 to 0.79 W/(m·K) measured by the laser flash method for lanthanum zirconate coatings deposited by APS. The thermal conductivity was further reduced to ~0.42 W/(m·K) by using amorphous feedstock, due to a more uniform microstructure of the coatings and a higher porosity associated with the formation of nanopores [36].…”

Section: Discussionmentioning

confidence: 99%

Thermal and mechanical properties of crack-designed thick lanthanum zirconate coatings

Weber

Lein

Grande

et al. 2014

Journal of the European Ceramic Society

View full text Add to dashboard Cite

Vertical cracks are beneficial in thermal barrier coatings due to enhanced thermomechanical compliance. Accordingly, an aqueous nitrate based precursor solution was atomized on stainless steel substrates by spray pyrolysis to deposit thick crack-designed lanthanum zirconate coatings. Coatings with designed crack patterns were deposited and characterized by electron microscopy, tribology, Vickers indentation, and thermal diffusivity. The crystallization of the coatings was investigated by in situ high temperature X-ray diffraction. The green coatings crystallized from 600 °C and the pyrochlore structure was formed after heat treatment at 1000 °C. Crystalline lanthanum zirconate multilayered coatings with small crack spacing and crack opening exhibited a higher density, a higher hardness, lower thermal diffusivities, and higher thermal conductivities compared to crystalline monolayered coatings of similar thickness with large crack spacing and crack opening. The thermal diffusivity of the coatings, ~28 mm 2 /s at room temperature, was similar to the values reported for yttria-stabilized zirconia plasma sprayed coatings.

show abstract

Section: Discussionmentioning

confidence: 99%

Thermal and mechanical properties of crack-designed thick lanthanum zirconate coatings

Weber

Lein

Grande

et al. 2014

Journal of the European Ceramic Society

View full text Add to dashboard Cite

show abstract

“…9, the thermal conductivities of the LZ coating decrease with the increase of temperature till 1200 K due to lattice scattering, and the conductivities increase again above 1200 K due to radiation contribution. The conductivities also depend on coating porosity [10,31,38,45,46,51]. In Vassen and Zhu's works, the porosities of the LZ samples were very low so the thermal conductivities were much larger than those of the porous coatings in Guo,…”

Section: Thermal Conductivitymentioning

confidence: 97%

“…by Guo [45] Exp. by Chen [46] Calc. by Guo [51] Low thermal conductivity is the primary advantage of LZ coatings over the YSZ coatings.…”

Section: Thermal Conductivitymentioning

confidence: 99%

Lanthanum zirconate based thermal barrier coatings: A review

Zhang

Guo

Jung

et al. 2017

Surface and Coatings Technology

192

View full text Add to dashboard Cite

This review article summarizes the latest information about the manufacturing techniques of lanthanum zirconate (La2Zr2O7, LZ) powder and La2Zr2O7 based thermal barrier coatings (TBCs). Lanthanum zirconate is a promising candidate material for TBC applications, due to its lower thermal conductivity and higher thermal stability compared to other traditional TBC systems. In this work, the physical, thermal, and mechanical properties of the powder and coatings are evaluated. The durability experiments of the TBCs in various thermal, mechanical, and corrosive conditions is also reviewed. In addition, theoretical studies on the powder and coatings properties are presented. Finally, future research directions of lanthanum zirconate as TBC applications are proposed.

show abstract

“…[7] Thermal conductivities of the pyrochlore La 2 Zr 2 O 7 reported in the literature are shown in Figure 6. [18,[44][45][46][47][48][49][50][51][52][53][54][55][56] The conductivities vary significantly, but are in the same range as those of YSZ with 7-8 wt pct Y 2 O 3 from Figure 1. Some of the reported values are lower than those of YSZ and one report [46] has a very different temperature dependence (i.e., increases strongly with increasing temperature) which was attributed to changes in the microstructure during the measurements.…”

Section: Thermal Conductivitymentioning

confidence: 99%

“…[14,23] Changes in microstructures during heat treatment or operation can cause coarsening of the microstructure, which can lead to increases in the thermal conductivity of the coating. Increases in the thermal conductivity after heat treatment or high temperature use of zirconiabased materials [22,38,62,84] and pyrochlores [15,47,62] have been reported. For example, the increases in the thermal conductivities of the materials shown in Figure 14 after various heat treatments are shown in Figure 15.…”

Section: Thermal Conductivitymentioning

confidence: 99%

Zirconia and Pyrochlore Oxides for Thermal Barrier Coatings in Gas Turbine Engines

Fergus

2014

Metallurgical and Materials Transactions E

View full text Add to dashboard Cite

One of the important applications of yttria-stabilized zirconia (YSZ) is as a thermal barrier coating for gas turbine engines. While YSZ performs well in this function, the need for increased operating temperatures to achieve higher energy conversion efficiencies, requires the development of improved materials. To meet this challenge, some rare-earth zirconates that form the cubic fluorite-derived pyrochlore structure are being developed for use in thermal barrier coatings due to their low thermal conductivity, excellent chemical stability, and other suitable properties. In this paper, the thermal conductivities of current and prospective oxides for use in thermal barrier coatings are reviewed. The factors affecting the variations and differences in the thermal conductivities and the degradation behaviors of these materials are discussed.

show abstract

Thermophysical properties of lanthanum zirconate coating prepared by plasma spraying and the influence of post-annealing

Cited by 79 publications

References 35 publications

Thermal and mechanical properties of crack-designed thick lanthanum zirconate coatings

Thermal and mechanical properties of crack-designed thick lanthanum zirconate coatings

Lanthanum zirconate based thermal barrier coatings: A review

Zirconia and Pyrochlore Oxides for Thermal Barrier Coatings in Gas Turbine Engines

Contact Info

Product

Resources

About