PREPARATION OF PLATINUM-FREE LASER GLASS.
Abstract
The problem of platinum inclusions in laser glass was investigated by two separate approaches simultaneously; namely, the improvement of platinum lined melters and the development of an all-ceramic melter. In the former, the major cause of platinum inclusions was identified as the formation of platinum oxide at elevated temperatures and its subsequent vaporization and deposition on exposed molten glass surfaces. This was largely eliminated with the use of inert atmospheres. The inert atmosphere introduces the possibility of direct interaction between the glass and platinum which was investigated but not completely resolved. A 50-lb capacity, platinum lined, inert atmosphere furnace producing glass of good optical quality is now in operation. In the all-ceramic melter approach, evaluation of existing ceramic materials led to the design and construction of a 'bottom-casting' system fabricated from a high purity mullite material. This furnace, also of 50-lb capacity, is now in operation. Several modifications were made to improve the optical quality of the glass produced. Melts to date, have been designed to investigate the stirring parameters of the system. The resulting glass contains varying degrees of striae but exhibits excellent absorption characteristics, equal to that produced in a platinum crucible indicating that the high purity mullite is not a source of iron contamination. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Aug 01, 1969
- Accession Number
- AD0692504
Entities
People
- Richard F. Woodcock