Kinetic study of La2O3-Al2O3-SiO2 glass infiltration into spinel preforms

Abstract

Spinel powder having a particle size of 0.9 mm was calcined for 30 min at 1300oC, followed by ball milling for 4 h, to obtain the spinel particle size of 3.29 mm. The die-pressed spinel was presintered at 1100oC for 2 h and then lanthanum aluminosilicate glass was infiltrated at 1080oC for 0~2 h to investigate the penetration kinetics in glass-spinel composite. The infiltration distance is parabolic in time due to capillarity. The strength and the fracture toughness of glassspinel composites were 317 MPa and 3.56 MPa · m1/2, respectively and dual microstructure of column (needle) and polygonal shapes as a result of recrystallization was observed due to the high calcination temperature.$