Effects of Ta <sub>2</sub> O <sub>5</sub> content on mechanical properties and high‐temperature performance of Zr <sub>6</sub> Ta <sub>2</sub> O <sub>17</sub> thermal barrier coatings
Qing Liu, Xiaopeng Hu, Wang Zhu, Jinwei Guo, Zhenyu Tan
Abstract
Abstract Zr 6 Ta 2 O 17 /YSZ double ceramic top coat thermal barrier coatings (TBCs) with different Ta 2 O 5 content are prepared by atmospheric plasma spraying (APS). The effects of Ta 2 O 5 content on mechanical properties and high‐temperature performance of Zr 6 Ta 2 O 17 TBCs are investigated. With the decrease in Ta 2 O 5 content, the hardness and fracture toughness of the Zr 6 Ta 2 O 17 coating increases from 12.833 to 15.117 GPa and from 3.3592 to 3.7753 MPa m 1/2 , respectively. The Zr 6 Ta 2 O 17 coating specimens with different Ta 2 O 5 content do not delaminate from the substrate except the edge peeling after 180 h of oxidation or 2000 thermal cycles at 1150°C. The Zr‐12Ta specimen (the molar ratio of ZrO 2 /Ta 2 O 5 of 0.88:0.12) presents the more excellent mechanical properties and high‐temperature performance. The reduction in Ta 2 O 5 content will improve the mechanical properties, high‐temperature oxidation, and thermal cycle performance of Zr 6 Ta 2 O 17 /YSZ double ceramic top coat TBCs.