Pore Forming Mechanism of Forsterite Insulation Materials Synthesized by Molten Salt Method

• Published in: Key Engineering Materials 2016-07, Vol.697, p.134-137
• Main Authors: Song, Yun Fei, Zhu, Hong Xi, Deng, Cheng Ji, Ding, Jun
• Format: Article
• Language: English
• Subjects: Decomposition; Forming; Forsterite; Fused salts; Insulation; Porosity; Scanning electron microscopy; Sodium carbonate
• ISSN: 1013-9826; 1662-9795; 1662-9795
• DOI: 10.4028/www.scientific.net/KEM.697.134

The forsterite thermal insulation materials were synthesized by molten salt method with forsterite and NaCl-Na2CO3 salt, sintered at 1000°C, 1050 °C, 1100°C and 1150°C respectively. Studying complex pore structures is the key to understand the mechanism of pore-forming. The mechanism of the variation in the heterogeneous pore structure was analyzed based on differential thermal analysis, thermogravimetry, high-pressure mercury intrusion porosimetry and scanning electron microscope. The results show that the NaCl-Na2CO3 salt play the role of promoting sintering in liquid environment at high temperature as well as forming pore as placeholder. The mechanism of pore-forming contains three parts: the pores < 6.6 μm are mainly formed by sodium carbonate decomposition under high temperature and vapor pressure; the forming way of 6.6~66μm derives from carbonate decomposition and salt evaporate jointly; The salt stay in the slender and curved space shaped by the rearrangement of forsterite particles, forms the pore diameter of > 66 μm after salt dissolves in water.