Combining Ultrafast Laser Texturing and Laser Hardening to Enhance Surface Durability by Improving Hardness and Wear Performance

Abstract

Aluminum alloy 7075 is utilized widely across marine, aerospace, and automotive sectors. However, its surface wear resistance has hindered its application in certain tribological environments. Addressing this challenge, the current study examines a hybrid laser method to increase surface wear resistance by combining two techniques: ultrafast laser texturing and laser‐based surface hardening. Ultrafast laser processing is conducted using 3 W laser power, 100 kHz pulse repetition rate, 4 mm s−1 scanning speed, and three different scan patterns. After the texturing operation, laser‐based surface hardening is then performed on these textures using a continuous wave laser. The laser heat treatment is conducted using laser powers of 400 and 500 W with three different scan speeds of 1, 2, and 3 mm s−1. Microhardness evaluations show a notable increase in hardness, with the hardest sample exhibiting a 17.8% increase compared to the pristine sample. The laser‐textured and laser heat‐treated samples exhibit a significant reduction in the average coefficient of friction and wear volumes compared to samples that were laser‐textured but not laser heat‐treated. The investigated laser processing strategy offers a promising approach for surface modification, enhancing both mechanical properties and wear resistance of aluminum alloy 7075 surfaces.