Processing Windows of Ni625 Alloy Fabricated Using Direct Energy Deposition

Abstract

Herein, we developed a process window for Ni625 alloy fabricated using a Nikon Lasermeister laser powder direct energy deposition unit. The process map illustrates the relationship between the laser power, scan speed, and effective energy density, established by examining the correlation between the microstructure and mechanical properties. All samples exhibited a bimodal microstructure comprising equiaxed and columnar dendrite grains, and the dendrite arm spacing decreased with increasing scan speed. The tensile behavior of each sample demonstrated minimal variation, and the values were comparable to those reported previously. The ultimate tensile and yield strengths ranged from 1008 ± 2 to 941 ± 9 and 682 ± 11 to 640 ± 7 MPa, respectively. This study highlights the remarkable manufacturability of Ni625 alloy for additive manufacturing across diverse parameter sets, demonstrating that a single ideal process set does not exist for each material and machine. Instead, multiple “recipes” may be employed to achieve similar outcomes.This article is protected by copyright. All rights reserved.