Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
1575247 | Materials Science and Engineering: A | 2014 | 6 Pages |
Abstract
The low fracture toughness of lanthanum zirconate (La2Zr2O7, LZ) greatly impedes its wide application as thermal barrier coatings (TBC). The 3Â mol% Y2O3-stabilized tetragonal zirconia polycrystals (3Y-TZP) have been introduced to toughen the brittle LZ ceramics. The dispersive 3Y-TZP undergoes a simultaneous t-m transformation upon cooling below a critical volume fraction x of 3Y-TZP, above which its tetragonal phases can however be preserved. The different stabilities of 3Y-TZP second phases arise from a variation of residual tensile stress within them. The fracture toughness has been greatly improved by dispersing the tetragonal particulates (t-3YSZ) in the LZ matrix and the primary toughening mechanisms are phase transformations of the dispersive second phases and the residual compressive stress within the matrix. An anticipated increase of fracture toughness from the ferroelastic toughening and the residual compressive stress toughening highlights the great potentials to improve coating durability by depositing tâ²-3YSZ/LZ composite TBCs by the industrial non-equilibrium route.
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Physical Sciences and Engineering
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Authors
Yanfei Wang, Ping Xiao,