Design of long-term ablation protective Zr_0.92Ta_0.04Si_0.04O₂ coating via large lattice distortion and limited phase precipitation

Thermally sprayed Zr-Ta-Si-O coatings were investigated to overcome the oxygen blocking limitations of traditionally self-derived porous ZrO₂ layer. The individual solid solution of Ta and Si into ZrO₂ lattice was respectively found trapped in the rapid phase precipitation and volatile loss, thus exhibiting insufficient ablation property. The as-designed Zr_0.92Ta_0.04Si_0.04O₂ coating successfully acquired a near-zero linear recession rate (-0.10 μm/s) after 900 s cyclic ablation (2.4 MW/m², 15 cycles). Key reasons can be attributed to a continuous sintering promotion and secondary phase precipitation limitation via large lattice distortion, where that of Zr_7/8Ta_1/16Si_1/16O₂ lattice exhibits over 200 % increase than Zr_7/8Ta_1/8O₂ lattice.