Raghavan Krishnaswamy

US Patent:

60869534, Jul 11, 2000

Filed:

Mar 12, 1999

Appl. No.:

9/267869

Inventors:

Srimathy Raghavan - Ellington CT
Raghavan Krishnaswamy - Ellington CT

International Classification:

C23C 1606

US Classification:

42725531

Abstract:

A method for manufacturing a guide pin is disclosed, which comprises machining a metal substrate core; optionally depositing an intermediate coating onto the substrate core; and depositing an insulative ceramic coating onto the intermediate coating by a chemical vapor deposition process under pressure conditions of up to about 500 torr, wherein the Rockwell C hardness of the metal core is greater than or equal to about 45, and the surface roughness values of the as-deposited coating are Ra less than or equal to about 35 microinches and Rmax less than or equal to about 250 microinches.

US Patent:

59254122, Jul 20, 1999

Filed:

Jul 25, 1997

Appl. No.:

8/900742

Inventors:

Srimathy Raghavan - Ellington CT
Raghavan Krishnaswamy - Ellington CT

International Classification:

C23C 1600

US Classification:

4272481

Abstract:

A method for manufacturing a guide pin is disclosed, which comprises maching a metal substrate core; and depositing an insulative ceramic coating by the Bernex chemical vapor deposition process, wherein the Rockwell C hardness of the metal core is greater than or equal to about 45, and the surface roughness value of the as-deposited coating are Ra less than or equal to about 35 microinches and Rmax less than or equal to about 250 microinches.

US Patent:

61750972, Jan 16, 2001

Filed:

Mar 11, 1999

Appl. No.:

9/266470

Inventors:

Srimathy Raghavan - Ellington CT
Raghavan Krishnaswamy - Ellington CT

International Classification:

B21J 1308

US Classification:

219158

Abstract:

A guide pin comprising a metal core and a generally smooth, non-porous insulative ceramic layer disposed on the metal core. An intermediate layer comprising titanium-carbonitride (TiCN) may be disposed on the metal core, thereby improving bonding of the ceramic layer to the guide pin assembly. In an important feature, the insulative layer is generally nonporous and has high hardness, and thus exhibits excellent wear resistance. The intermediate and insulative layers are deposited by a chemical vapor deposition process known as the "Bernex" process that results in a very hard, generally nonporous coating.