Developments of Hard Carbon Films and Their Tribological Properties

in Frontier Carbon Technology Project

 

Akihiro TANAKA

 

Research Center for Advanced Carbon Materials, National Institute of Advanced Industrial Science and Technology

1-2 Namiki, Tsukuba, Ibaraki 305-8564, Japan

 atanaka@mel.go.jp, Fax:+81-298-61-7007, Tel:+81-298-61-7069

 

1. INTRODUCTION

In Japan, a national project of Frontier Carbon Technology (FCT) has been conducted from 1998 in a five-years plan. In FCT project, the developments of hard carbon thin films has been conducted for the tribological applications. In this paper, these developments are introduced briefly.

 

2. DEVELOPMENTS FOR TRIBOLOGICAL APPlCATIONS

Toward the development of hard carbon films with friction coefficient of less than 0.1 and wear rate of less than 1*10-7mm3/Nm, DLC films have been deposited using a antenna-induced microwave plasma CVD method with the mixture gas of CH4 and H21). Until now, a DLC film with friction coefficient of 0.11 and wear rate of 3*10-8mm3/Nm.has been developed.

For the development of DLC films with high adhesive force to substrate, DLC films have been deposited using a apparatus which consists of ECR plasma CVD method combined with high energy ion implantation method2). The adhesive force of a DLC film with the N2+ ion implantation at the initial stage of film growth was clearly improved; the critical load of the DLC film with N2+ ion implantation was about 220 mN by a scratch test.

In order to develop a deposition technique for three dimensional substrates, DLC films have been deposited using a plasma based ion implantation method3). By selecting the suitable deposition parameters, the dependency of DLC film thickness on the direction of microwave was considerably decreased.

The effects of various factors such as environments, normal loads, and mating materials on friction and wear of pure DLC and Si-DLC films have been examined4). The rupture load of DLC films in dry air was smaller than that in high humid air. The friction decreased with increasing hardness of mating materials.

Besides the tribological application, anti-corrosive films under high temperature conditions have been developed. These films have been made using both spraying method and sputtering method. The diamond deposition technique on a large area substrate has been developed using a microwave plasma CVD method.

 

REFERENCES

1)K. Wazumi, A. Tanaka, and Y. Koga, Synopses of ITC Nagasaki 2000, (2000)434.

2)K. Fuchigami, M. Horiuchi, K. Takashima, and K. Uematsu, Synopses of ITC Nagasaki 2000, (2000)436.

3)K. Watanabe, etc, Synopses of ITC Nagasaki 2000, (2000)434.

4)Y. Ozmen, A. Tanaka, and T. Sumiya, JST Trib. Conf., (2000)67.