Quartz-enhanced CaO-SiO2 ceramic fiber boards: Enhancement mechanism of mechanical strength and high-temperature dimensional stability

To enhance the mechanical strength and high-temperature dimensional stability of CaO–SiO 2 ceramic fiber boards, composite ceramic fiber boards were fabricated via vacuum filtration with quartz particles of varying content and particle sizes. Results show that moderate quartz addition reinforces the interwoven fiber skeleton, increases bulk density, and significantly improves compressive strength—from 1.41 MPa (without quartz) to 3.53 MPa at 60 wt% quartz. Finer particles (d 50 = 5.8 μm) further enhance strength, reaching 5.68 MPa, due to better pore filling and higher packing density. Quartz also improves thermal stability through high-temperature expansion, effectively mitigating shrinkage. A mathematical model based on composite linear shrinkage was established to predict dimensional changes between 1000–1400 ℃, with good agreement between calculated and experimental values. This study reveals the reinforcement mechanism of quartz in CaO–SiO 2 ceramic fiber composites, offering theoretical and practical guidance for the design of high-performance thermal insulation materials.