Friction and wear behavior analysis of the stainless steel surface fabricated by laser texturing underwater

• Texturing underwater suppresses thermal effect and increases the ablation depth.
• Friction coefficient drops as the texture acts as lubricant and debris reservoirs.
• Micro-bearings effect reduces the friction coefficient at high sliding speed.

Laser surface texturing is an advanced technology to reducing the friction between two contact surfaces in relative motion. Experiments both underwater and in the air were performed to evaluate the influence of processing environment on the machining quality. Processing parameters including water depth, pulse width and repetition rate significantly influence the morphology of micro dimples. It is found that thermal effect of laser can be suppressed in the water. Meanwhile, recoil pressure of water evaporation could increase the depth of generated micro dimples. Results of the friction and wear tests show that the friction coefficient of laser textured surface is greatly reduced at high sliding speed and heavy load situations where micro-dimples act as micro-bearings, lubricant and debris reservoirs.