Wetting, densification and phase transformation of La2O3/A2O3/B2O3-based glass–ceramics

A lead-free, non-alkali La2O3–Al2O3–B2O3 (LAB) glass with Al2O3 filler had been investigated for low temperature co-firing ceramic (LTCC) application. The glass forming window and several physical properties of the LAB systems were investigated by ICP, TMA, XRD, DSC, and SEM/EDS. The results show that the densification and crystallization temperatures of LAB/Al2O3 were between 700 °C and 950 °C and depended greatly on the formulation. Crystalline phase LaBO3 (LB) and LaAl2B3O9 (L2A3B) crystallized starting at 825 °C and 925 °C, respectively. High degree of densification and crystallization of one glass–Al2O3 composition (L30A) was observed with the microstructure composed of tabular L2A3B grains interlocking with submicron Al2O3 and LB grains.