Refractory articles and methods for forming same

Patent metadata

Field	Value
Publication number	US-9758434-B2
Application number	US-201615167634-A
Country	US
Kind code	B2
Filing date	May 27, 2016
Priority date	Jun 1, 2015
Publication date	Sep 12, 2017
Grant date	Sep 12, 2017

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 first phase and a second phase;
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 wt % for a total weight of the body; and
a third phase comprising composite grains including mullite and zirconia, the third 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 content of zirconia (ZrO 2 ) in the body is within a range including at least 0.1 wt % and less than 1.8 wt %.

3. The refractory article of claim 1 , wherein the first phase comprises alumina.

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

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

6. The refractory article of claim 1 , wherein the second phase comprises mullite including alumina and silica.

7. The refractory article of claim 1 , wherein the second phase comprises mullite grains.

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

9. The refractory article of claim 7 , wherein the mullite grains comprise 3Al 2 O 3 ·2SiO 2 , 2A 1 2 O 3 ·SiO 2 , or a combination thereof.

10. The refractory article of claim 7 , wherein the mullite grains of the second phase are essentially free of zirconia.

11. The refractory article of claim 7 , wherein the mullite grains comprise non-stoichiometric mullite.

12. The refractory article of claim 7 , 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.

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

14. The refractory article of claim 1 , wherein essentially all of the zirconia in the body is contained within the third phase.

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

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

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

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

19. The refractory article of claim 18 , wherein the slot intersects a side surface of the body and extends along a bottom surface of the body.

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

Assignees

• Saint-Gobain Ceram & Plastics Inc

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

• C04B2235/3241

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

• C04B2235/72

  Products characterised by the absence or the low content of specific components, e.g. alkali metal free alumina ceramics · 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

• C04B35/101 Primary

  Refractories from grain sized mixtures · CPC title