HU Qiguo, GU Xingyong, DONG Weixia, LUO Ting, QIU Boxin
(School of Materials Science and Engineering, Jingdezhen Ceramic Institute, Jingdezhen 333403, Jiangxi, China)
Abstract: In this paper, lightweight and high-strength mullite samples with hollow sphere structure were prepared by in situ solid-phase method using fly ash floating beads and industrial aluminum hydroxide. The influence of fly ash floating beads and industrial aluminum hydroxide formulation on the bulk density and the compressive strength of the samples were investigated. The crystalline phases and microstructure of the samples were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The formation mechanism of mullite hollow spheres was also analyzed. The experimental results show that hollow spheres constructed by needle-like mullite were obtained and exhibited some attractive properties such as the compressive strength of 6.9-14 MPa, and the bulk density lowered to 0.48-0.66 g/cm3, when the mass ratio of fly ash floating beads and industrial aluminum hydroxide changed from 35 : 65 to 55 : 45. These results demonstrate mullite hollow spheres prepared from fly ash floating beads and industrial aluminum hydroxide have potential applications in the manufacture of lightweight materials.
Key words: micro-structure; mullite hollow sphere; fly ash floating beads; lightweight