Research on Diamond-Like Carbon Coatings for Low-Friction Valve Lifters Nissan Motor Company, Limited

Format:

Conference/Event

Author/Creator:

Yasuda, Yoshiteru, author.

Conference Name:

SAE 2003 World Congress & Exhibition (2003-03-03 : Detroit, Michigan, United States)

Language:

English

Physical Description:

1 online resource

Place of Publication:

Warrendale, PA SAE International 2003

Summary:

One important development area for obtaining better fuel economy is to reduce mechanical friction losses in engine components. The valvetrain is a significant source of mechanical friction loss in an automobile engine, especially at low speeds where fuel economy is most important.This paper describes the potential use of diamond-like carbon (DLC) coatings at the cam/follower interface in a bucket-type valvetrain. Using a pin-on-disk tester, a motored valvetrain friction apparatus and a bench test rig, the frictional performance of DLC coatings was tested. Experimental data indicate that under a lubricated condition, DLC coatings produced by a plasma CVD (chemical vapor deposition) technique did not show a sufficient effect on reducing friction (only a 20-25% reduction) contrary to our expectations. DLC coatings prepared by arc-ion plating and containing less hydrogen showed superior frictional performance compared with CVD-DLC coatings under a lubricated condition. Results obtained with a motored valvetrain friction tester indicate that an arc ion-plated DLC coating on a valve lifter can reduce friction loss by almost 45% compared with a phosphated steel valve lifter in a conventional valvetrain. Surface hardness, film thickness and surface roughness can be designed to match the intended valvetrain application

Notes:

Vendor supplied data

Publisher Number:

2003-01-1101

Access Restriction:

Restricted for use by site license