The effect of laser in-situ induced graphene-like micro-texture on the friction and wear properties of ductile cast iron

Abstract

Picosecond fiber laser was subjected on surface of ductile cast iron to induce graphene-like micro-texture array and enhance the tribological properties. The size of the dimples was regulated in the range of 5 μm–110 μm. The in-situ fabrication process was carried out on the workpiece surface in parallel manner and the scanning speed can be up to 3 m/s. The formation mechanism of graphene-like structure was analyzed. The tribological properties of the textured samples were investigated using a ball-on-disk tribometer. The results showed that the laser textured samples exhibit low coefficient of friction and the anti-wear properties were improved significantly. The textured sample showed no distinct wear pit, while the non-textured sample showed typical wear pit with depth up to 15 μm. Volume wear rate was reduced by 69.6 ± 6.9%. The graphene-like micro-texture array conducted by picosecond fiber laser scanning will not change the material isotropic, and the improved tribological properties are attributed to the combined effects of the increased surface hardness, improved heat dispersion property and entrapment of wear debris.

Keywords

• Picosecond laser
• Laser texturing
• Ductile cast iron
• Tribological properties