STUDY ON THE MECHANISM OF CRACK FOMATION IN INCONEL 625 FORMED BY DIRECT LASER METAL DEPOSITION

Abstract

ABSTRACT
Direct Laser Metal Deposition (DLMD) is one of the contemporary forming technologies with
significant potential for application across critical industries. This technology proves its worth in
the manufacture of intricate components from challenging materials, such as nickel alloys and
titanium alloys... DLMD represents a complex process, where the structural and mechanical
properties of the formed material are heavily reliant on technological factors. Crucially, the
assessment of defects residing within the deposition layers emerges as a focal yardstick,
commanding current research endeavors. This paper investigates the influence of energy density
within the molten region on crack formation within the deposition layers of Inconel 625 nickel alloy
formed using DLMD technology. Results show that lower energy densities lead to poor adhesion
between the forming layers and the substrate material, thereby initiating cracks within the
deposition layer. The outcomes of the analysis unveil the existence of clusters comprised of
aluminum oxide and titanium oxide within the fissures. These clusters stand as contributory agents
to the diminished cohesion between the deposition layers, ultimately instigating the emergence
of cracks at locations where these oxide aggregates reside. Subsequently, these cracks propagate
along the paths delineated by crystalline structures, traversing through the deposition layers.