XIAO Hanning ,MA Weiwei ,TAO Meng

(College of Materials Science & Engineering, Hunan Univers ity, Changsha 410082)

Abstract: Al₂O₃-SiO₂-P₂O₅ glas ses were prepared by melting-quenching method and then heat treated for in-situ crystallization.Structure and crystallizing behavior were analysized by IR,DSC,XRD and SEM.The effects of P₂O₅ content on the structure and crystallization of ASP glass were discussed.Results indicate that 35 ~50wt% P₂O₅ can form a stable glass in ASP system at lower P₂O₅ content,P⁵⁺ mainly exists in [PO₄] tetrahedron without P=O bond.With the increase of P₂O₅ content,the P-O-bond become weaker and the P=O bond strengthen,which means that P⁵⁺ exists in [PO₄] tetrahedron with partial P=O bond. At higher P₂O₅ content, the stability of ASP glass decreases and the crystallization tendency enhances . AlPO₄ is the primariy crystal phase in the crystallized sample,although a little Al (PO)₃ phase was observed. When the crystallization temperature elevated from 650℃ to 800℃,the content of crystal phase increased, and YPO₄ phase was observed.

Keyword: Al₂O₃-SiO₂-P₂O₅ glass ,P₂O₅ content,glass structure,crystallization