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Gd_2Zr_2O_7 has been considered as a promising thermal barrier coating candidate,but its toughness and thermal expansion coefficient(TEC) need to be improved.In this study,Gd_(2-x)Zr_(2+x)O_(7+x/2)(x = 0,0.1,0.3,0.5,0.7) compounds were produced to improve the toughness and enlarge the TEC.Gd_2Zr_2O_7 and Gd_(1.9)Zr_(2.1)O_(7.05) exhibited pyrochlore structure,while Gd_(2-x)Zr_(2+x)O_(7+x/2)(x=0.3,0.5,0.7) consisted of pyrochlore and t’-ZrO_2 phases.With increasing ZrO_2 content,the pyrochlore in the compounds had decreased lattice parameter,and its ordering degree decreased when x≤0.3,then it almost kept unchanged with higher ZrO_2 content.Among the Gd_(2-x)Zr_(2+x)O_(7+x/2) ceramics investigated,the toughness of the compounds increased with increasing ZrO_2 content,while Gd_(1.7)Zr_(2.3)O_(7.15) exhibited the largest TEC.The related mechanisms were discussed in detail.
Gd_2Zr_2O_7 has been considered as a promising thermal barrier coating candidate, but its toughness and thermal expansion coefficient (TEC) need to be improved.In this study, Gd_ (2-x) Zr_ (2 + x) O_ (7 + x / 2 (x = 0,0.1,0.3,0.5,0.7) compounds were produced to improve the toughness and enlarge the TEC.Gd_2Zr_2O_7 and Gd_ (1.9) Zr_ (2.1) O_ (7.05) exhibited pyrochlore structure, while Gd_ (2-x (X +0.3, 0.5, 0.7) consisted of pyrochlore and t’-ZrO_2 phases. Increasing ZrO 2 content, the pyrochlore in the compounds had decreased lattice parameter, and its ordered degree decreased when x ≦ 0.3, then it almost kept unchanged with higher ZrO 2 content. Amgong the Gd_ (2-x) Zr_ (2 + x) O_ (7 + x / 2) ceramics investigated, the toughness of the compounds increased with increasing ZrO_2 content, while while Gd_ (1.7) Zr_ (2.3) O_ (7.15) exhibited the largest TEC.The related mechanisms were discussed in detail.