Laser Surface Modification of AISI 1025 Low Carbon Steel using Pulsed Nd:YAG Laser for Enhanced Surface Properties

This paper presents laser surface modification of AISI 1025 low carbon steel for enhance surface hardness properties. A Nd:YAG laser system with pulse mode was used in order to modify 10mm thick plate surface. Three controlled parameters were laser power, pulse duration and overlap percentage which ranged from 100 W to 200 W, 0.4 to 1.0 ms and 50% to 90% respectively. The metallographic and hardness of the treated samples were characterised. Metallographic study was conducted using optical microscope for laser modified layer thickness and grain size. Hardness properties were measured using Vickers indenter. The result show that hardness of laser treated area increased due to fine grain size produced in the laser modified layer. The overlap percentage increased significantly with decreasing laser scanning speed which was found to result in a lower hardness. These findings are important high wear applications such as may be found in semi-sold metal forming.