Host: The Japan Society of Mechanical Engineers
Name : [in Japanese]
Date : September 03, 2017 - September 06, 2017
When Diamond-Like Carbon (DLC) on a die is damaged by peeling and wear to lose its tribological performance, DLC is repaired through the following process: (1) Uninstallation of the die from a processing machine, (2) Removal of all the DLC film coated on the die, (3) Recoating of new DLC film, (4) Installation of the recoated die to the processing machine. However, most of damaged parts of DLC are localized, and thus we propose a new way of repairing such a local damage of DLC without uninstalling a coated die from a processing machine. In recoating new DLC onto the damaged part of DLC, some part of the new DLC overlaps the old DLC remaining on a die. Such an overlap may cause weak interface in repaid DLC, and thus we are required to give high-adhesive strength between old and new DLCs. For this purpose, we overcoated a new layer of Si-DLC film by plasma-enhanced chemical vapor deposition (PECVD), on a pre-coated layer of Si-DLC on a steel disk, so that we investigate the effect of cleaning process before peel-off load of the new layer was investigated. Disks successfully overcoated with a new layer after different cleaning time of 270, 300, 360 and 390 seconds were slid against a steel ball (SUJ2, JIS), where vertical load was increased by every 10 m of sliding distance. The peel-off loads obtained were 10, 12, 10, and 1.5 N for the cleaning time of 270, 300, 360 and 390 seconds, respectively, implying cleaning time of 300 seconds was optimum for maximizing the peel-off load.
