Raw batch for producing reaction-bonded silicon carbide refractory product

• US 5,563,108 A
• Filed: 05/25/1995
• Issued: 10/08/1996
• Est. Priority Date: 09/14/1994
• Status: Expired due to Term

• Current Assignee: Carborundum Co (Compagnie De Saint-Gobain S.A.)
• Original Assignee: Carborundum Co (Compagnie De Saint-Gobain S.A.)
• Inventors: Kim, Baek H.
• Primary Examiner(s): GROUP, KARL E
• Application Number:
  US08/450,596
• Time in Patent Office: 502 Days
• Field of Search: 501/92, 501/89
• US Class Current: 501/89
• CPC Class Codes: C04B 35/565 based on silicon carbide
• CPC Class Codes: C04B 35/591 obtained by reaction sintering

Abstract

This invention provides a reaction-bonded silicon carbide article having superior abrasion resistance, oxidation resistance and uniformity in which the bond phase comprises appreciable amounts of both silicon oxynitride and alumina. Also provided are a raw batch and a process for producing the reaction-bonded article.

Claims

1. A raw batch for producing a reaction-bonded silicon carbide refractory article, said raw batch comprising between about 88 wt % and about 98.5 wt % solids and between about 1.5 wt % and about 12 wt % vehicle, said solids including about 60 wt % to about 85 wt % silicon carbide, about 5 wt % to about 16 wt % silicon, about 5 wt % to about 14 wt % alumina, and about 1 wt % to about 7 wt % silica.

2. The raw batch of claim 1 wherein said solids include about 65 wt % to about 80 wt % silicon carbide, about 7 wt % to about 14 wt % silicon, about 8 wt % to about 11 wt % alumina, and about 2 wt % to about 4 wt % silica.

3. The raw batch of claim 1 wherein the silicon carbide comprises primarily the alpha polymorph and includes a mixture of silicon carbide grains having different particle sizes, none of which exceed about 5 mm in size.

4. The raw batch of claim 1 wherein the silicon comprises particles having sizes in the range of about 74 μ

m and finer.

5. The raw batch of claim 1 wherein the alumina is reactive alumina having a surface area of at least about 2 m² /g.

6. The raw batch of claim 1 wherein the silica is fume silica.

7. The raw batch of claim 6 wherein the silica has a surface area of about 20-24 m² /g.

8. The raw batch of claim 1 wherein the content of silicon carbide s about 79 wt %, the silicon about 7 wt %, the alumina about 10 wt %, and the silica about 4 wt %.

10. The raw batch of claim 6 wherein the refractory article exhibits a modulus of rupture greater than about 1000 psi.

9. A raw batch for producing a reaction-bonded silicon carbide refractory article, said raw batch comprising between about 88 wt % and about 98.5 wt % solids and between about 1.5 wt % and about 12 wt % vehicle, said solids including about 60 wt % to about 85 wt % silicon carbide, about 5 wt % to about 16 wt % silicon, about 5 wt % to about 14 wt % alumina, and about 1 wt % to about 7 wt % silica, said raw batch being capable of yielding a reaction-bonded silicon carbide refractory article comprising a silicon carbide phase and a bond phase, said silicon carbide phase comprising between about 65 wt % and about 85 wt % of the article, said bond phase comprising about 15 wt % to about 35 wt % of the article, said bond phase comprising at least about 30 wt % of both silicon oxynitride and at least about 30 wt % of alumina.