Role of Oxide Additives in Stabilizing Zirconia for Coating Applications

Abstract

Zirconium dioxide (Z1O2) is a ceramic with a variety of industrial applications as a refractory material, and it is used in electronic packaging, biomedicine, and advanced engines. Unfortunately, pure zirconia undergoes a destructive phase transformation that severely limits its uses. However, some oxide additives have been found to control this transformation and ultimately lead to significant improvements in the material. This report summarizes the role that oxide additives play in controlling these transformations, and the resulting applications of ZrCVbased coatings are discussed.

Cubic zirconia in >2370 °C impact melt records Earth's hottest crust

“…Therefore, the transformations among zirconia polymorphs that took place after zircon dissociation necessarily also occurred in the melt sheet at post-shock low-pressure conditions, which constrains the stability of cubic zirconia to extremely high temperatures. Impurities, such as REE and Y, can also stabilize cubic zirconia at lower temperatures (Swab, 2001) (Supplementary File item 7). However, the levels of trace elements present in the ZrO 2 are much less than 0.1 wt% ( Supplementary File item 4), and so the effects of impurities on the cubic to tetragonal zirconia transformation temperature were negligible (Swab, 2001) ( Supplementary File item 7).…”

“…Impurities, such as REE and Y, can also stabilize cubic zirconia at lower temperatures (Swab, 2001) (Supplementary File item 7). However, the levels of trace elements present in the ZrO 2 are much less than 0.1 wt% ( Supplementary File item 4), and so the effects of impurities on the cubic to tetragonal zirconia transformation temperature were negligible (Swab, 2001) ( Supplementary File item 7). Therefore, the former presence of cubic zirconia in the Mistastin Lake zircon indicates that the impact melt temperature was in excess of 2370 °C (Fig.…”

Structural evolution in reactive RF magnetron sputtered (Cr,Zr)2O3 coatings during annealing

“…Pure ZrO 2 exists in three different crystal structures: the room temperature stable monoclinic phase and the metastable phases; tetragonal (from ~1170 °C) and cubic fluorite (from ~2300 °C) [17][18][19]. The tetragonal phase can be stabilized at standard temperature and pressure by alloying with different early transition metal oxides, the most common being Y 2 O 3 [20,21].…”

Physical vapor deposition and thermal stability of hard oxide coatings

“…The alloy content marking the boundary between monoclinic, tetragonal and cubic phase for some common, mostly rare earth, alloy element are described in ref [65]. The tetragonal phase is the most commonly used phase and can be stabilized at STP by alloying with different early transition metal oxides, the most common being Y2O3 [66,67]. This phase is often used as a thermal barrier coating in high-temperature applications, coated on, e.g, turbine components [68].…”