Densification and phase development of spodumene-cordierite glass powder mixtures

The sintering and crystallization of spodumene-cordierite glass-ceramics that are made from mixtures of Li2O-Al2O3-SiO2 (LAS) and MgO-Al2O3-SiO2 (MAS) glass powders were investigated. Pure LAS and MAS powders have good sinterability. However, the densification of LAS was drastically reduced when small amounts of MAS were added. When larger amounts of MAS were added, the amount of densification further increased. The decrease in the Li2O content in the LAS glass promoted the densification of the mixed glass samples. The above-mentioned results can be explained by examining the crystallization temperature, which is influenced by the interactions between the LAS and MAS glass particles. The lower the temperature of crystallization, the less sintering occurred. For the sintered samples, the phase that crystallized from the MAS glass was alpha-cordierite, and that which crystallized from the LAS glass was beta-spodumene or high-quartz solid solution, depending on the Li2O content in the LAS glass.