Performance Analysis of Fiber Laser Micro-Marking on Aluminium 7075 Alloy

Abstract

Analyzing the performance of fiber laser micro-marking on aluminium alloy under focus–defocus conditions entails determining the way varying the focus position during the marking process impacts the overall performance. A special process variable defocus height refers to the distance between the focal point of the laser beam and the surface of the material being marked. In micro-marking, the focal point can be moved above or below the surface to generate distinct effects. The paper determines the optimal parameters for laser micro-marking on aluminium 7075 alloy, including laser power, pulse frequency, scan speed, defocus height (the distance between the top surface and the focal point), and duty cycle, for mark quality and characteristics such as depth and mark width. Experimental results showcase that laser parameters affect mark width and depth nonlinearly. In addition, small variations in laser power, scanning speed, or focus height, have led to moderate changes in dimensions of the mark geometry. A target mark of 40[Formula: see text][Formula: see text]m in width and 25[Formula: see text][Formula: see text]m in depth is achieved by combining optimum settings like a power of 23.862[Formula: see text]w, a duty factor of 45%, a pulse frequency of 76.0506[Formula: see text]Khz, a scanning speed of 0.70[Formula: see text]mm/s, and a defocus height of 0.7[Formula: see text]mm.