Host: The Japan Society of Mechanical Engineers
Name : [in Japanese]
Date : February 28, 2017 - March 03, 2017
The authors proposed a new evaluation method “Cyclic indentation tests”. In this method, 118.6N of cyclic force of 118.6 N (1.46 GPa of Hertzian contact pressure) acts on DLC films without sliding. The present paper describes evaluation of DLC films strength and failure mode using the cyclic indentation test. DLC films, which consisted of Cr/C gradient and a-C:H layers, were prepared using unbalanced magnetron sputtering. Thickness of DLC films was approximately 2μm. Substrates of DLC films are flat plates as lapped, and material of them was SCM415. Three kinds of DLC films, which have different hardness by changing substrate bias voltages were prepared. As a results, DLC films were damaged around indentation tracks, and failure modes were thought to be so called “buckling pattern”. In addition, protrusions were observed around indentation tracks. Height of these protrusions were smaller as increasing hardness of DLC films.
