Texturing of micro-lubricant pores on high-speed steel surface by fiber laser

The objective of this research is to study the fabrication of micro-lubricant pores on high-speed steel by using a laser texturing process. Effects of laser power and focal position on size of micro-lubricant pores were investigated. Specimens were made of JIS SKH51 high-speed steel with a hardness of 63 ± 2 HRC and polished smooth surface. This steel grade is one of the materials utilized for making tools and die. A laser surface texturing process with fiber laser source using an optical fiber as the active gain medium was employed. Studying influence of laser power demonstrated the diameter of micro- lubricant pores and the heat- affected zone diameter increased when the laser power increased, the laser power of 18 watts gave larger diameter of 41 μm. For the focal position, the heat- affected zone diameter became larger with
raising the focal position. Elevating the focal position far from the surface resulted in larger diameter of micro- lubricant pores. At the focal position of 1 mm. and laser power of 18 watts exhibited the largest diameter of micro-lubricant pores, 67 μm. The laser texturing process can be utilized for the fabrication of the micro-lubricant pores with a diameter between 30 to 67 μm. and this process is able to texture array of dimples over the area of flat surface.