Coating method for crucibles used in crucible pulling of quartz glass comprises applying protective coating to tungsten crucible, coating consisting of tungsten and second metal consisting of iridium, rhenium, osmium or ruthenium

摘要

Coating method for melting crucibles for use in crucible pulling of quartz glass comprises applying a protective coating to a tungsten crucible. The coating consists of tungsten and a second metal consisting of iridium, rhenium, osmium or ruthenium. This is present in an amount corresponding to the phase boundary of a solid mixed phase which is stable at the working temperature and contains tungsten and a maximum of 25 At% of the second metal. An independent claim is included for melting crucibles with a protecting coating as described above.