Study on the influence of scanning strategy on the morphology of laser micro-dimple texturing

Laser surface texturing is an advanced technology which can effectively improve surface tribological properties and has been attracted wide attention. However, the large diameter micro-dimple cannot be finished by fixed-point pulse processing, and fewer researches about the effect of laser scanning strategy on large diameter micro-dimple texture have been reported. Therefore, the effect of laser scanning strategy on the morphology of large diameter micro-dimple texturing is discussed in this work. An experiment of micro-dimple texturing on the 40Cr steel temples is performed by using a nanosecond laser. The effect of laser scanning mode on the micro-dimple texture is investigated to determine a reasonable laser scanning mode. Meanwhile, the influence of scanning interval on the micro-dimple texture with different diameters is studied under the best scanning mode. Results show that the diameter of the micro-dimples which are processed by the fixed-point pulse is about 48.1μm, and the spiral scanning is the best scanning mode for the large diameter micro-dimple texture. For spiral scanning, with the increase of scanning interval, the diameter of micro-dimples increases slightly, while the depth of micro-dimples, the height and the width of craters decreases. In order to ensure that the micro-dimple texture has good formability, the scanning interval can be properly floated on the basis of 10μm, but the scanning interval should not be close to the diameter of micro-dimples processed by the fixed-point pulse.