US4687749A
Expired / Lapsed
US
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Refractory glass-ceramics containing enstatite
Assignee: Corning Glass Works
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Filing: 1986-10-24
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Granted: 1987-08-18
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Expires: 2006-10-24
Abstract
Abstract This invention is concerned with the production of glass-ceramic articles wherein enstatite constitutes the predominant crystal phase. Compositions exhibiting a high modulus of rupture, a use temperature in excess of 1200° C., and a high fracture toughness consist essentially, expressed in terms of weight percent on the oxide basis, of about 20-35% MgO, 2-12% Al 2 O 3 , 40-70% SiO 2 , and at least one metal oxide in the indicated proportions selected from the group consisting of 0-2% Li 2 O, 0-4% CaO, 0-12% SrO, and 0-17% BaO, at least 0.5% Li 2 O being required when present alone and at least 1% SrO and/or BaO being required in the absence of Li 2 O. Compositions exhibiting a use temperature of 1500° C. consist essentially, expressed in terms of weight percent on the oxide basis, of about 30-35% MgO, 53-58% SiO 2 , and 10-14% ZrO 2 .
Inventors
- 👤 George H. Beall
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 17:26
CPC Classifications
C; C04; C04B; C04B35/00; C04B35/01; C04B35/16; C04B35/18; C04B35/195; C03; C03C; C03C10/00; C03C10/0036; C03C10/0045; C04B35/20; C04B2235/00; C04B2235/02; C04B2235/30; C04B2235/32; C04B2235/3201; C04B2235/3203; C04B2235/3205; C04B2235/3206; C04B2235/3208; C04B2235/3213; C04B2235/3215; C04B2235/3217; C04B2235/3231; C04B2235/3232; C04B2235/3244; C04B2235/36; C04B2235/70; C04B2235/80; C04B2235/96
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
162 words
A glass-ceramic article exhibiting a high modulus of rupture, a use temperature of at least 1200° C., a high fracture toughness, and a crystal content of at least 90% by volume, said article containing enstatite as the predominant crystal phase, at least one secondary crystal phase selected from the group consisting of β-spodumene solid solution, Ba-osumilite, celsian, anorthite, cristobalite, and strontium feldspar, and having a composition consisting essentially, expressed in terms of weight percent on the oxide basis, of about 20-35% MgO, 2-12% Al 2 O 3 , 40-70% SiO 2 , and at least one metal oxide in the indicated proportion selected from the group consisting of 0-2% Li 2 O, 0-4% CaO, 0-12% SrO, and 0-17% BaO, at least 0.5% Li 2 O being required when present alone and at least 1% CaO and/or SrO and/or BaO being required in the absence of Li 2 O, said composition being essentially free from Na 2 O, K 2 O, and fluoride.
Claim 2
Dependent Claim
162 words
A glass-ceramic article exhibiting a high modulus of rupture, a use temperature of at least 1200° C., a high fracture toughness, and a crystal content of at least 90% by volume, said article containing enstatite as the predominant crystal phase, at least one secondary crystal phase selected from the group consisting of β-spodumene solid solution, Ba-osumilite, celsian, anorthite, cristobalite, and strontium feldspar, and having a composition consisting essentially, expressed in terms of weight percent on the oxide basis, of about 20-35% MgO, 2-12% Al 2 O 3 , 40-70% SiO 2 , and at least one metal oxide in the indicated proportion selected from the group consisting of 0-2% Li 2 O, 0-4% CaO, 0-12% SrO, and 0-17% BaO, at least 0.5% Li 2 O being required when present alone and at least 1% CaO and/or SrO and/or BaO being required in the absence of Li 2 O, said composition being essentially free from Na 2 O, K 2 O, and fluoride.
Claim 3
Dependent Claim
48 words
A glass-ceramic article according to claim 1 also containing 5-15% TiO 2 +ZrO 2 , consisting of 0-15% TiO 2 and 0-15% ZrO 2 , wherein said secondary crystal phase also contains crystals selected from the group consisting of tetragonal ZrO 2 , rutile, zircon, and mixtures thereof.
Claim 4
Dependent Claim
26 words
A glass-ceramic article according to claim 1 consisting essentially of about 30-34% MgO, 2-6% Al 2 O 3 , 60-66% SiO 2 , and 1-5% BaO.
Claim 5
Dependent Claim
46 words
A glass-ceramic article exhibiting a use temperature of 1500° C., containing enstatite as the predominant crystal phase, and having a composition consisting essentially, expressed in terms of weight percent on the oxide basis, of about 30-35% MgO, 53-58% SiO 2 , and 10-14% ZrO 2 .
Claim 6
Dependent Claim
46 words
A glass-ceramic article exhibiting a use temperature of 1500° C., containing enstatite as the predominant crystal phase, and having a composition consisting essentially, expressed in terms of weight percent on the oxide basis, of about 30-35% MgO, 53-58% SiO 2 , and 10-14% ZrO 2 .
Claim 7
Dependent Claim
62 words
A glass-ceramic article exhibiting a use temperature in excess of 1400° C., containing enstatite as the predominant crystal phase, and having a composition consisting essentially, expressed in terms of weight percent on the oxide basis, of about 30-35% MgO, 53-58% SiO 2 , 10-14% ZrO 2 , and up to 2% B 2 O 3 and/or 5% Al 2 O 3 .
Claim 8
Dependent Claim
62 words
A glass-ceramic article exhibiting a use temperature in excess of 1400° C., containing enstatite as the predominant crystal phase, and having a composition consisting essentially, expressed in terms of weight percent on the oxide basis, of about 30-35% MgO, 53-58% SiO 2 , 10-14% ZrO 2 , and up to 2% B 2 O 3 and/or 5% Al 2 O 3 .
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