2006 年 47 巻 549 号 p. 983-987
A series of experiments was carried out to investigate the influence of hard particles on diamond-like carbon (DLC) coating damage in the strip-ironing process. Three types of commercially available DLC coating were used as die coatings on alloy tool steel SKD11 substrates. Three types of hard particles, namely, sand, SiC and Al2O3, were used. Experiments under dry conditions showed no DLC coating damage after ironing with a dull-finished sheet, but DLC coating damage can be observed at the interface inlet when using a sheet finished with abrasive paper. In the case of aluminum sheet (A1050-H24), severe galling is observed under dry conditions. When using a lubricant with hard particles, no DLC coating damage can be observed in samples with sand or Al2O3 particles, but severe DLC coating damage can be observed in samples with SiC particles. The degree of DLC coating damage becomes greater with a high-tensile-strength steel sheet than with an aluminum sheet. The TiN coating is also destroyed by SiC particles but TiC coating damage is negligible.