Browse Prior Art Database

Flame Sprayed Ceramic Coating for Heat Efficiency

IP.com Disclosure Number: IPCOM000108345D
Original Publication Date: 1992-May-01
Included in the Prior Art Database: 2005-Mar-22
Document File: 2 page(s) / 56K

Publishing Venue

IBM

Related People

Deans, D: AUTHOR

Abstract

The development of this design was necessary due to the continual failures of the crucible due to the beam "tunneling" into the slug and burning through the copper.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 100% of the total text.

Flame Sprayed Ceramic Coating for Heat Efficiency

       The development of this design was necessary due to the
continual failures of the crucible due to the beam "tunneling" into
the slug and burning through the copper.

      This condition was a result of the high conductive losses
during operation.

      In a water-cooled (Egun) copper crucible application, the heat
loss due to conduction can be as high as 75% (see the figure).

      Present practice to reduce this heat loss is to use a liner
under the source material.  In the past this has not proven
successful for AlCu applications because of it breaking down into the
slug, thus causing contamination.

      The method proposed to reduce the conductive loss is to flame-
spray a ceramic layer on the underside of the AlCu pocket which is
NOT in direct contact with the source material.  This coating adds an
insulating barrier between the AlCu source, through the copper wall
to the cooling water.  Thus, more of the heat energy remains in the
source and reduces initial power requirements and the beam
"tunneling" effect.

      The prototype being tested is presently showing that the power
needed to obtain the same or better rate is 8.6% less (7700 W vs.
8433 W, average), and the melt is more uniform without gross
tunneling.

      Also, filament life increases, egun regulation is smoother
resulting in more stable rate for uniform thickness.