SiC-ZrC ultra-ince liflerde çift oksidasyon bariyeri oluşturan Zr türlerinin kendi kendine yönlenen çift yönlü yeniden dağılımı

Özet (abstract)

Silicon carbide (SiC) ultrafine fibers hold great promise for flexible thermal protection systems, yet their service temperature is severely limited by oxidative degradation above 1300 °C. Herein, SiC-ZrC ultrafine fibers (SZF) with linearly tunable Zr content are fabricated by electrospinning, electron-beam curing, and carbothermal pyrolysis. The optimal SZF-20 maintains structural integrity after oxidation at 1600 °C for 30 min and at 1300 °C for 30 h in air. Focused ion beam sectioning and transmission electron microscope reveal temperature-dependent spatial redistribution of Zr species across the oxide scale. During high-temperature oxidation, nonstoichiometric ZrO x C y intermediates redistribute inward along the advancing oxidation front and accumulate at the oxide-matrix interface, forming a linear, high-melting-point inner ZrO 2 barrier. Meanwhile, some ZrO 2 grains segregate outward as the SiO 2 matrix crystallizes into cristobalite, pinning grain boundaries to create an outer passivation layer. This dual-barrier architecture synergistically suppresses oxygen ingress and microcrack formation, thereby enabling reliable short-term high-temperature oxidation tolerance up to 1600 °C. The assembled fiber aerogels demonstrate nearly full shape recovery with residual strain below 1% following 80% compression, good thermal shock stability over repeated rapid cycles between 1600 and 25 °C, and low thermal conductivity, highlighting their great potential as reusable high-temperature thermal protection materials.

Yazarların özeti; kaynağından alınmıştır. Journal of Material Science and Technology, 2026 · DOI ↗