Abstract:

Regular micro-dimples are processed on 45 steel surfaces by a LM-YLP-20F-Ⅱ laser marking machine. Ring-on-block line contact wear and friction tests are conducted under dry sliding in order to study tribological properties of laser surface textures on 45 steel surfaces. The hardness of the inside and outside of dimples are examined, worn surfaces of specimens are observed by SEM, and influence mechanisms of laser surface textures on 45 steel surfaces with different original surface hardness are investigated. The results show that the geometric parameters of laser surface textures have a significant influence on wear resistance under dry sliding, and under certain conditions, laser surface textures can reduce wear loss successfully. Laser texturing will change the surface hardness of specimens drastically. When the original surface hardness of textured specimens is low, laser dimples will sustain and protect materials nearby, thus reduce adhesive wear. However, when the original surface hardness of textured specimens is high, laser dimples will abrade and plough the mating surface seriously, which leads to the increase of abrasive wear.

Key words: dry sliding, friction and wear tests, laser processing, surface texture