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Browse Prior Art Database

Surface Hardening of Ceramic and Glass Materials

IP.com Disclosure Number: IPCOM000104140D
Original Publication Date: 1993-Mar-01
Included in the Prior Art Database: 2005-Mar-18
Document File: 2 page(s) / 37K

Publishing Venue

IBM

Related People

Cuomo, JJ: AUTHOR

Abstract

This invention describes a structure and method for enhancing the properties of glass and ceramic materials by surface coating with amorphous diamond, which induces high compressive stress into the surface, provides coating of micro voids and cracks in the surface with a material that has the intrinsic properties of diamond and provides the surface with the chemical stability of diamond. Films of pure amorphous carbon with a high fraction of sp sup 3 bonds have been prepared by ion beam, laser beam and cathodic arc deposition. The properties of these films approach that of diamond as the sp sup 3 fraction increases. Some cathodic arc deposited carbon has sp sup 3 content of about 90% and the elastic constant and hardness measured essentially that of diamond, i.e.

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Surface Hardening of Ceramic and Glass Materials

      This   invention   describes  a  structure  and  method  for
enhancing the properties of glass and ceramic  materials  by surface
coating  with amorphous diamond, which induces high compressive
stress into the  surface,  provides  coating  of micro  voids  and
cracks in the surface with a material that has the intrinsic
properties of  diamond  and  provides  the surface  with  the
chemical stability of diamond.  Films of pure amorphous carbon with a
high fraction of sp sup 3 bonds have  been  prepared  by  ion  beam,
laser  beam  and cathodic  arc  deposition.    The  properties of
these films approach that of diamond as the sp sup 3 fraction
increases.  Some cathodic arc deposited carbon has sp sup 3 content
of about 90% and the elastic constant and  hardness measured
essentially that of diamond, i.e., 1100 GPa and 90 GPA respectively.
The films have a very  large  compressive stress,  which  will
further  enhance  the stability of the material coated.  We see the
coating  of  glass  or  ceramic materials  with  amorphous  dense
carbon as a way to improve the properties of these  materials  and
to  maintain  these property enhancements due to the chemical
stability provided by the surface.

      Griffith  and  Orocoan  have  shown  that, in amorphous
materials, brittle fracture  occurs when initiated by micro-cracks
through tensile failure.  If t...