Effect of oscillation process parameters in direct laser metal deposition 3d printing deposition for single layer track using Ti-6al-4v: microhardness analysis

Abstract This study focuses on optimizing Direct Laser Metal Deposition (DLMD) process parameters to enhance microhardness across deposition regions using Ti-6Al-4V materials for powder and substrate. DLMD, a prominent additive manufacturing method, is valued for its precision in creating complex 3D geometries; however, achieving consistent and high microhardness remains challenging. Through the application of the Taguchi method and ANOVA, the research identifies optimal oscillation parameters with an overlap value, OL of 70% and a travel rate, RV of 800 mm/min significantly improve microhardness. Signal-to-noise ratio analysis highlights the travel rate as the most influential factor, particularly affecting the top and middle deposition layers. Microscopic analysis reveals distinct microstructures, including equiaxed grains at the top, cellular structures in the middle, and columnar grains near the substrate, attributed to varying cooling rates and thermal gradients. Regression models further clarify the relationship between process parameters and microhardness. The findings present a robust framework for optimizing DLMD processes, ensuring improved material properties, stability, and manufacturing precision.