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Sintering, Crystallization, and Properties of B 2 O 3 /P 2 O 5 ‐Doped Li 2 O·Al 2 O 3 ·4SiO 2 Glass‐Ceramics
Author(s) -
Shyu JiinJyh,
Lee HsinHui
Publication year - 1995
Publication title -
journal of the american ceramic society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.9
H-Index - 196
eISSN - 1551-2916
pISSN - 0002-7820
DOI - 10.1111/j.1151-2916.1995.tb08630.x
Subject(s) - crystallization , sintering , materials science , thermal expansion , dopant , doping , quartz , mineralogy , microstructure , phase (matter) , analytical chemistry (journal) , chemical engineering , metallurgy , chemistry , optoelectronics , organic chemistry , chromatography , engineering
Sintering, crystallization, microstructure, and thermal expansion of Li 2 O·Al 2 O 3 ·4SiO 2 glass‐ceramics doped with B 2 O 3 , P 2 O 5 , or (B 2 O 3 + P 2 O 5 ) have been investigated. On heating the glass powder compacts, the glassy phase first crystallized into high‐quartz s.s., which transformed into β‐spodumene after the crystallization process was essentially complete. The effects of dopants on the crystallization of glass to high‐quartz s.s. and the subsequent transformation of high‐quartz s.s. to β‐spodumene were discussed. The major densification occurred only in the early stage of sintering time due to the rapid crystallization. All dopants were found to promote the densification of the glass powders. The effect of doping on the densification can fairly well be explained by the crystallization tendency. All samples heated to 950°C exhibited a negative coefficient of thermal expansion ranging from about −4.7 × 10 ‐6 to −0.1 × 10 ‐6 K ‐1 . Codoping of B 2 O 3 and P 2 O 5 resulted in the highest densification and an extremely low coefficient of thermal expansion.