Browse Prior Art Database

Fusion of Opaque Crucibles

IP.com Disclosure Number: IPCOM000012178D
Publication Date: 2003-Apr-15
Document File: 2 page(s) / 25K

Publishing Venue

The IP.com Prior Art Database

Abstract

This idea is to fuse opaque quartz pieces, crucibles and other parts such are cylinders, rings, near net shape pieces, etc. by fusing the quartz under a reducing atmosphere.

This text was extracted from a Microsoft Word document.
This is the abbreviated version, containing approximately 53% of the total text.

<!DOCTYPE HTML PUBLIC "-//IETF//DTD HTML//EN">

Fusion of Opaque Crucibles

ABSTRACT

This idea is to fuse opaque quartz pieces, crucibles and other parts such are cylinders, rings, near net shape pieces, etc. by fusing the quartz under a reducing atmosphere.

Fusion of Opaque Crucible parts and other opaque pieces by fusing under a reducing atmosphere

I.         � � � � � � � � � � � SUMMARY OF IDEA

This idea is to fuse opaque quartz pieces, crucibles and other parts such are cylinders, rings, near net shape pieces, etc. by fusing the quartz under a reducing atmosphere.� A gas atmosphere of 13% normal atmosphere and of 87% a reducing blanket of Helium + Hydrogen mix is used.

II.         � � � � � � � � � � � PROBLEM TO BE SOLVED

Normally (up to this time) opaque quartz pieces were made by mixing a special doped sand. The sand is normally doped with 40 ppm of silicon carbide. When this doped sand is fused, the silicon carbide reacts with the sand and generates many, many small bubbles.  The silicon carbide doping is sometimes hard to control and depending on the variability in the silicon carbide raw material lots, there can be some variability in the product. In addition, there are always serious concerns with the manufacture of this material since the SiC doped sand can contaminate the preparation and fusion areas with negative side effects for weeks to come.

In the current process, the sand is doped with approximately 40 ppm of granular silicon carbide material. During crucible fusion, the silicon carbide reacts with the hot molten sand and forms carbon monoxide and silicon monoxide. These two gaseous species generate a myriad of small bubbles dispersed through the product. The opaque material is noted for and sold for the fact...