S1160405 Effects of Residual Gases during Deposition on the Friction Properties of PECVD-DLC
At a Glance
Section titled āAt a Glanceā| Metadata | Details |
|---|---|
| Publication Date | 2015-01-01 |
| Journal | The Proceedings of Mechanical Engineering Congress Japan |
| Authors | Hotaka SHIBASAWA, Hiroyuki Kousaka, Noritsugu Umehara, Xinerui DENG |
| Institutions | Nagoya University |
Abstract
Section titled āAbstractāDLC (Diamond-Like Carbon) has excellent mechanical properties such as high hardness, low friction and high wear resistance. One of the main coating methods of DLC is PECVD, which enables ultra-high-speed coating at larger than 100 Ī¼m/h if combined with an appropriate high-density plasma represented by MVP (Microwave sheath-Voltage combination Plasma). For practically achieving high-throughput in DLC coating by MVP, not only coating time but also evacuation time should be shortened. If vacuum condition including not negligible amount of residual gases is allowed during coating, it leads to shorten the evacuation time before coating. Thus, in this research, in order to understand the effect of a residual gas, or water, during coating on Si-containing DLC (Si-DLC) deposited, we compared 3 Si-DLCs deposited under different 3 vacuum conditions; 1) evacuated down to 4Ć10^<-4> Pa with turbo-molecular pump, 2) evacuated down to 1 Pa only with rotary pump, and 3) water was added to the vacuum condition. Deposition of 3 Si-DLCs under the 3 vacuum conditions was conducted with not only MVP but also conventional DC plasma for comparison. As a result, it was observed in DC that 1) hardness decreased from 18.6 GPa to 10.8 GPa, 2) ID/IG increased from 0.25 to 0.41, 3) Si/C increased from 0.37 to 0.76, and 4) O/C increased from 0.02 to 0.42, with increasing of residual water during coating. Similar results were obtained in MVP, however, the increased/decreased ranges of the 4 parameters were decreased; in other words; the effect of residual water was suppressed by employing MVP instead of DC plasma. In spite of thus changes in films, friction coefficient in PAO oil was almost the same value from 0.08 to 0.1 in all specimens.