Evaluation of tribo-characteristics of diamond-like-carbon containing Si by metal forming simulators

Environmental protection is an important issue among current manufacturing. Meanwhile, tribology in metal forming is making a great contribution to solve the problems related to both environmental and manufacturing aspects. High performance hard coatings and lubricants are in great demands for solving those problems. Diamond-like-carbon containing silicon, DLC-Si, which is an attractive material to reduce friction and prevent pick-up, has already been developed and used in the sliding parts of automobiles. This new coating has high adhesion strength, which has been proved in the application of metal forming. In this paper, its tribological characteristics are evaluated with different pressures and sliding velocities by four typical tribo-simulators: rotating compression test, strip-ironing test, ball-penetration test, and backward extrusion test. These results show that DLC-Si demonstrated high tribological properties in anti-galling and low friction. That means there is a high possibility for the application of DLC-Si on dies for cold metal forming.

► The DLC-Si coating without intermediate layers is developed.
► The coating demonstrates high properties in anti-galling and low friction in four severe tribo-simulators for cold metal forming.
► That means there is a good possibility of applying the coating to dies for cold-metal forming.