Room-temperature-cured MoSi2-phosphate emissivity coating with a self-sealing structure

• Published in: Materials & design Vol. 256; p. 114364
• Main Authors: Cao, Xianqi, Zhao, Kunlong, Liu, Tong, Song, Laiming, Wu, Yize, Zhang, Chunhong, Cao, Wenxin, Bai, Jianwei, Liu, Lijia, Xue, Jinlong, Zhang, Yun, Zhu, Jiaqi
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.08.2025; Elsevier
• Subjects: High-emissivity coating; Phosphate adhesive; Room-temperature forming; Thermal protection material; High-emissivity coating; Phosphate adhesive; Thermal protection material; Room-temperature forming
• ISSN: 0264-1275
• DOI: 10.1016/j.matdes.2025.114364

[Display omitted] •Novel room-temperature-curing phosphate-MoSi2 coating with a self-sealing structure.•Combined phosphate, borosilicate glass powder, and MoSi2 in high-emissivity coating.•Molten borosilicate glass powder occludes pores and blocks oxygen diffusion.•Good stability, oxidation resistance, and impact damage up to 1200 °C.•After calcination at 1200 °C, the emissivity at room temperature reaches a peak of 0.89. While emissivity coatings on thermal insulation materials in aircrafts can help radiate aerodynamic heat flux, traditional high-temperature sintering oxidizes emissive agents, thereby degrading their emissive properties. We present a novel room-temperature-curing phosphate-MoSi2 coating with a self-sealing structure, using low-melting-point borosilicate glass powder (BSP) and MoSi2 as functional fillers. Considering that both the melting of BSP and MoSi2 oxidation occur at similar temperatures, molten BSP occludes pores and blocks oxygen diffusion to protect MoSi2 at medium and high temperatures. After treatment at 1200 ℃, the emissivity at room temperature reaches a peak of 0.89. The slurry infiltrates the porous substrate under capillary action, forming a gradient structure to mitigate interfacial thermal stress, and exhibits excellent interfacial bonding strength. The slurry’s excellent room-temperature formability further allows facile repair of small-area damages of existing coating. Compared to conventional methods, the proposed approach is superior in forming, mechanical strength, and emissivity stability, offering significant potential for emergency repair of thermal materials.