Tribological properties of dimpled surface alloying layer on carbon steel

The effect of surface structure and coating on tribological properties of 45# carbon steel disc was analyzed. A Nd:YAG laser was used to generate microdimples on steel surfaces. Dimples with diameter of 150 m and depth of 50 m were distributed in an orbicular array on disc surface. Then the alloying element Mo was sputtered to 45# carbon steel disc surface by means of double glow plasma technology. Diffusion Mo alloying layer with 30 min thickness and high hardness up to 0.025 was formed on the disc surface. Tribological experiments of three types samples (smooth, texturing and texturing+alloying) were conducted with a pin-on-disc tribometer. It is found that the dimpled-samples are most effective for reducing friction in comparison with smooth steel surfaces, improving the lubricating state from boundary to hydrodynamic region.