Abstract The instant invention is directed to the production of highly crystalline glass-ceramic articles demonstrating high intrinsic mechanical strength and toughness containing crystals of canasite and/or agrellite and/or fedorite as the predominant crystal phase. The articles have overall compositions consisting essentially, expressed in terms of weight percent on the oxide basis, of about ______________________________________ SiO 2 45-75
CaO 8-30
F 3.5-12
Na 2 O 3-15
K 2 O 0-20
Na 2 O + K 2 O 5-25
B 2 O 3 0-6
Al 2 O 3 0-7
ZrO 2 0-12
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Inventors
👤 George H. Beall
Bibliographic Details
Application Number—
JurisdictionUS
Data Sourcegoogle_patents
Last Synchronized2026-10-24 15:01
CPC Classifications
C; C03; C03C; C03C10/00; C03C10/16
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
76 words
A highly crystalline glass-ceramic article exhibiting high toughness and a modulus of rupture in excess of 20,000 psi, wherein the predominant crystal phase is canasite and/or agrellite and/or fedorite, and having an overall composition consisting essentially, expressed in terms of weight percent on the oxide basis, of about ______________________________________
SiO.sub.2 45-75
CaO 8-30
F 3.5-12
Na.sub.2 O 3-15
K.sub.2 O 0-20
Na.sub.2 O + K.sub.2 O 5-25
B.sub.2 O.sub.3
0-6
Al.sub.2 O.sub.3
0-7
ZrO.sub.2 0-12
______________________________________
Claim 2
Dependent Claim
76 words
A highly crystalline glass-ceramic article exhibiting high toughness and a modulus of rupture in excess of 20,000 psi, wherein the predominant crystal phase is canasite and/or agrellite and/or fedorite, and having an overall composition consisting essentially, expressed in terms of weight percent on the oxide basis, of about ______________________________________
SiO.sub.2 45-75
CaO 8-30
F 3.5-12
Na.sub.2 O 3-15
K.sub.2 O 0-20
Na.sub.2 O + K.sub.2 O 5-25
B.sub.2 O.sub.3
0-6
Al.sub.2 O.sub.3
0-7
ZrO.sub.2 0-12
______________________________________
Claim 3
Dependent Claim
42 words
A glass-ceramic article according to claim 1 wherein said composition consists essentially of about ______________________________________
SiO.sub.2 50-65
CaO 15-24
F 5-9
Na.sub.2 O 3-13
K.sub.2 O 3-15
Na.sub.2 O + K.sub.2 O 11-22
B.sub.2 O.sub.3
0--3
Al.sub.2 O.sub.3
0-3
ZrO.sub.2 0-8
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