Thermo-penetrative spreading behaviours of oil in lasered microgrooves on stainless steel 316L surfaces

The thermo-penetrative spreading behaviours of oil in microgrooves on stainless steel 316L surfaces were studied experimentally under temperature gradient conditions. An interface of smooth surface and microgrooved surface was designed to comparatively investigate the penetrative spreading of oil in microgrooves and the apparent spreading of oil on microgrooves and smooth surfaces. Then, microgrooves with different depths but a same width were laser processed to analyse the relationship between the actions of surface texture and temperature gradient on oil directional spreading. Results showed that the apparent oil on microgrooves extended directionally along the temperature gradient, leading to the lubricant loss from the high-temperature region to the lower, while the penetrative oil in microgrooves could spread rapidly from the low-temperature region to the higher under the obstruction of the thermocapillary effect, providing a potential method to enhance the lubrication.