LAUSR

In-situ-grown $$\upbeta \!\hbox {-Si}_{3}\hbox {N}_{4}$$β-Si3N4-reinforced $$\hbox {SiO}_{2}\textendash \hbox {Al}_{2}\hbox {O}_{3}\textendash \hbox {Y}_{2}\hbox {O}_{3}$$SiO2–Al2O3–Y2O3$$(\hbox {La}_{2}\hbox {O}_{3})$$(La2O3) self-reinforced glass–ceramic composites were obtained without any $$\upbeta \!\hbox {-Si}_{3}\hbox {N}_{4}$$β-Si3N4 seed crystal. These composites with different compositions were prepared in a nitrogen atmosphere for comparison of phase transformation and mechanical properties. The results showed that $$\hbox {SiO}_{2}\textendash \hbox {Al}_{2}\hbox {O}_{3}\textendash \hbox {Y}_{2}\hbox {O}_{3}$$SiO2–Al2O3–Y2O3$$(\hbox {La}_{2}\hbox {O}_{3})$$(La2O3) glass can effectively promote $$\upalpha $$α- to $$\upbeta \!\hbox {-Si}_{3}\hbox {N}_{4}$$β-Si3N4 phase transformation. The crystallized $$\hbox {Y}_{2}\hbox {Si}_{2}\hbox {O}_{7}\textendash \hbox {La}_{4.67}\hbox {Si}_{3}\hbox {O}_{13}$$Y2Si2O7–La4.67Si3O13 phases with a high melting point significantly benefited the high-temperature mechanical properties of the composites. The $$\hbox {Si}_{3}\hbox {N}_{4}\textendash \hbox {SiO}_{2}\textendash \hbox {Al}_{2} \hbox {O}_{3}\textendash \hbox {Y}_{2}\hbox {O}_{3}$$Si3N4–SiO2–Al2O3–Y2O3$$(\hbox {La}_{2}\hbox {O}_{3})$$(La2O3) glass–ceramic composites exhibit excellent mechanical properties compared with unreinforced glass–ceramic matrix, which is undoubtedly attributed to the elongated $$\upbeta \!\hbox {-Si}_{3}\hbox {N}_{4}$$β-Si3N4 grains. These glass–ceramic $$\hbox {Si}_{3}\hbox {N}_{4}$$Si3N4 composites with excellent comprehensive properties might be a promising material for high-temperature applications.