Eaton Corporation

Stephen B Caird

Jay M Larson

Sundaram L Narasimhan

Flavio A Rigamonti

John D Dingell, Iii

Charles E Pennock

Emory Z Pankas

Michael A Allibone

Antonio Gutierrez

A method is provided that in one embodiment is operative to form a wear resistant coating of titanium nitride on the outer surface of a metal valve such as an internal combustion engine poppet valve (100). In another embodiment, the method is operative to provide a valve made from titanium with an in situ zone of titanium nitride extending inwardly from the valve's outer surface. In yet another embodiment, the method is operative to provide a valve made from titanium with both a coating of titanium on the valve's outer surface and an in situ zone of titanium nitride extending inwardly from the valve's outer surface.

Titanium nitride coated valve and method for making

A process for providing an engine valve (2) with varied microstructure grain size is provided. The process includes the steps of: providing a slug (4) of suitable metallic valve composition having a grain size of less than about A.S.T.M. 8; solution heat treating slug (4) to provide a larger grain size and to substantially dissolve carbonitride stringers if present; and forging the solution heat treated slug (4) in a manner that provides a substantially uniformly distributed A.S.T.M. grain size of about 1 to about 7 in a central region beneath the combustion face of head (14) of valve (2) while cold working a seat face (16) on head (14) and extruding the stem (10) of valve (2) such that its microstructure grain size is less than about A.S.T.M. 8.

Process for providing valve members having varied microstructure

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Saginaw, MI, United States of America

Stephen B Caird