Browse Prior Art Database

Surface Hardening of Ceramic and Glass Materials

IP.com Disclosure Number: IPCOM000103650D
Original Publication Date: 1993-Jan-01
Included in the Prior Art Database: 2005-Mar-18
Document File: 1 page(s) / 43K

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 sp3 bonds have been prepared by ion beam, laser beam and cathodic arc deposition. The properties of these films approach that of diamond as the sp3 fraction increases. Some cathodic arc deposited carbon has sp3 content of about 90 percent and the elastic constant and hardness measured essentially that of diamond, i.e., 1100 GPa and 90 GPA respectively.

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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 sp3 bonds have
been prepared by ion beam, laser beam and cathodic arc deposition.
The properties of these films approach that of diamond as the sp3
fraction increases.  Some cathodic arc deposited carbon has sp3
content of about 90 percent 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 the surface can be protected from scratches,
atmospheric erosion and reaction or that the surface could be
enhanced in compressive...