Conceptual Protection Model for Especially Heat-Proof Materials in Hypersonic Oxidizing Gas Flows

Terentieva, V. S.; Астапов, А. Н.

doi:10.3103/s1067821218060172

Cited by 13 publications

(14 citation statements)

References 9 publications

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“…As a reference, we used samples of a C f /C-SiC composite with a base coating in the Si-TiSi 2 -MoSi 2 -TiB 2 system [11,27], for which the rate constant of heterogeneous recombination was determined earlier [30].…”

Section: Methodsmentioning

confidence: 99%

“…The presence of eutectics between components in the composition of the coatings improves the adhesion between the layers and to the substrate, accelerates the regeneration of the oxide film, and also to some extent compensates for the differences in the coefficients of thermal expansion of coatings and protected materials. The effectiveness of the protective action of coatings was confirmed under static oxidation conditions in air at 1650 • C [13,25], in an oxidizing gas flow at 1900 • C [22], in high-speed high-enthalpy air plasma flows at 1850 • C [11,24], 1950 • C [23], 2000 • C [26], and 2200 • C [13], as well as under the conditions of an ablation fire experiment at 2400 • C [25].…”

Section: Introductionmentioning

confidence: 99%

“…When designing coatings for extreme operating conditions, the concept of self-healing has become widespread [9,[11][12][13], based on the use in the structure of coatings of a glass phase or components capable of glass formation during operation. The glass phase encapsulates the underlying layers and heals microdefects, ensuring the operability of the composition until the nominal supply of glass-forming components is exhausted.…”

Section: Introductionmentioning

confidence: 99%

“…The role of the healing phase in the inner layers of coatings of the MoSi 2 -Mo 5 Si 3 -HfSi 2 /TaSi 2 /TaC and WSi 2 -W 5 Si 3 -HfSi 2 /TaSi 2 /TaC systems [22], Si-TiSi 2 -MoSi 2 -TiB 2 [11,23], Si-TiSi 2 -MoSi 2 -TiB 2 -SiC w [24], ZrSi 2 /Si-ZrSi 2 /SiC [25] and ZrSi 2 -MoSi 2 -ZrB 2 [13,26] perform eutectics between silicides [22] or between silicon and silicides [11,13,[23][24][25][26]. The presence of eutectics between components in the composition of the coatings improves the adhesion between the layers and to the substrate, accelerates the regeneration of the oxide film, and also to some extent compensates for the differences in the coefficients of thermal expansion of coatings and protected materials.…”

Section: Introductionmentioning

confidence: 99%

“…Special attention should be paid to heat-resistant self-healing coatings based on the Si-TiSi 2 -MoSi 2 -TiB 2 system, including [11,23,27], wt%: titanium 15-40, molybdenum 5-30, boron 0.5-2.5 and silicon-the remainder. In the process of obtaining coatings, a dendritic-cellular structure is formed from disilicide phases (Ti x Mo 1−x Si 2 (0.1 < x < 0.87), TiSi 2 , MoSi 2 ).…”

Section: Introductionmentioning

confidence: 99%

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Oxidation Resistance of a Si–TiSi2–MoSi2–TiB2–CaSi2 Coating on a Cf/C–SiC Substrate in High-Speed High-Enthalpy Air Plasma Flows

2021

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The results of a study on the development and testing of a heat-resistant coating in a Si–TiSi2–MoSi2–TiB2–CaSi2 system to protect Cf/C–SiC composites from oxidation and erosional entrainment in high-speed flows are presented here. The coating was formed using firing fusion technology on the powder composition. Oxidation resistance tests were carried out under static conditions in air at 1650 °C and under conditions of interaction with high-speed air plasma flows, with Mach numbers M = 5.5–6.0 and enthalpy 40–50 MJ/kg. The effectiveness of the protective action of the coating was confirmed at surface temperatures of Tw = 1810–1820 °C for at least 920–930 s, at Tw = 1850–1860 °C for not less than 510–520 s, at Tw = 1900–1920 °C for not less than 280–290 s, and at Tw = 1940–1960 °C for not less than 100–110 s. The values of the rate of loss of the coating mass and the rate constant of heterogeneous recombination of atoms and ions of air plasma on its surface were estimated. The performance of the coating was ensured by the structural-phase state of its main layer, and the formation and evolution on its surface during operation of a passivating heterogeneous oxide film. This film, in turn, is composed of borosilicate glass with titanium and calcium liquation inhomogeneities, reinforcing TiO2 microneedles and in situ Si2ON2 fibers. It was shown that at Tw≥ 1850–1860 °C, the generation of volatile silicon monoxide was observed at the “oxide layer–coating” interface, followed by the effects of boiling and breakdown degradation of the oxide film, which significantly reduced the lifespan of the protective action of the coating.

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Section: Methodsmentioning

confidence: 99%