Refractory articles and methods for forming same

Patent metadata

Field	Value
Publication number	US-10093580-B2
Application number	US-201715665002-A
Country	US
Kind code	B2
Filing date	Jul 31, 2017
Priority date	Jun 1, 2015
Publication date	Oct 9, 2018
Grant date	Oct 9, 2018

Abstract

A refractory article can include a body including a content of alumina of at least 60 wt %, a content of silica of not greater than 20 wt %, a content of zirconia of not greater than 20 wt % for a total weight of the body. In a particular embodiment, the body includes a third phase including composite grains including mullite and zirconia. The third phase including the composite grains can be present within a range including at least 1 wt % and not greater than 35 wt % for a total weight of the body.

First claim

What is claimed is:

1. A refractory article comprising:
a body including:
a content of alumina (Al 2 O 3 ) within a range including at least 60 wt % and not greater than 95 wt % for a total weight of the body;
a content of silica (SiO 2 ) within a range including at least 2 wt % and not greater than 20 wt % for a total weight of the body;
a content of zirconia (ZrO 2 ) within a range including at least 0.1 wt % and not greater than 2.5 wt % for a total weight of the body;
a phase comprising composite grains including mullite and zirconia, the phase present within a range including at least 1 wt % and not greater than 35 wt % for a total weight of the body.

2. The refractory article of claim 1 , wherein the body comprises a first phase comprising the alumina.

3. The refractory article of claim 1 , wherein the body comprises alumina grains.

4. The refractory article of claim 3 , wherein the alumina grains have an average grain size (D50ag) within a range including at least 1 micron and not greater than 2 mm.

5. The refractory article of claim 2 , wherein the body comprises a second phase comprising mullite including alumina and silica.

6. The refractory article of claim 5 , wherein the second phase comprises mullite grains.

7. The refractory article of claim 6 , wherein the mullite grains comprise stoichiometric mullite.

8. The refractory article of claim 6 , wherein the mullite grains comprise 3Al 2 O 3 .2SiO 2 , 2Al 2 O 3 .SiO 2 , or a combination thereof.

9. The refractory article of claim 6 , wherein the mullite grains of the second phase are essentially free of zirconia.

10. The refractory article of claim 6 , wherein the mullite grains comprise non-stoichiometric mullite.

11. The refractory article of claim 6 , wherein the mullite grains have an average grain size (D50mg) within a range including at least 0.1 mm and not greater than 3 mm.

12. The refractory article of claim 1 , wherein a majority of the zirconia in the body is contained in the phase including the composite grains.

13. The refractory article of claim 1 , wherein essentially all of the zirconia in the body is contained within the phase including the composite grains.

14. The refractory article of claim 1 , wherein the composite grains of the phase have an average grain size (D50cg) within a range including at least 0.1 mm and not greater than 3 mm.

15. The refractory article of claim 1 , wherein the body comprises:
a first phase comprising alumina grains;
a second phase comprising mullite grains; and
the third phase comprising composite grains including mullite and zirconia.

16. The refractory article of claim 1 , wherein the body comprises a thermal shock resistance of at least 55% of an initial MOR.

17. The refractory article of claim 1 , wherein the body comprises at least one slot formed in a major surface of the body.

18. The refractory article of claim 1 , wherein the body is essentially free of chromia (Cr 2 O 3 ).

Assignees

• Saint Gobain Ceramics

Inventors

• Case Allan R
• Cortellini Edmund A
• Huang Hansong
• Kuhn Melanie
• Levoy Nancy F
• Towle Wesley S

Classifications

• C04B2235/80

  Phases present in the sintered or melt-cast ceramic products other than the main phase · CPC title

• C04B2235/725

  Metal content · CPC title

• C04B2235/3418

  Silicon oxide, silicic acids or oxide forming salts thereof, e.g. silica sol, fused silica, silica fume, cristobalite, quartz or flint · CPC title

• C04B2235/78

  Grain sizes and shapes, product microstructures, e.g. acicular grains, equiaxed grains, platelet-structures · CPC title

• C04B2235/3241

  Chromium oxides, chromates, or oxide-forming salts thereof · CPC title