Additive manufacturing by means of laser-aided directed metal deposition of 2024 aluminium powder: Investigation and optimization

Abstract

Directed metal deposition by means of laser beam is investigated in this article. The process is receiving increasingly interest in the frame of additive manufacturing to the purpose of maintenance, repair and overhaul of condemned products when severe conditions hindering the working order have been experienced. Minimal distortion, reduced heataffected zones and better surface quality are benefited in comparison with conventional techniques. Namely, metal feeding of 2024 aluminium powder is considered to produce clad traces on 2024 aluminium plates, aiming to give grounds for repairing damaged real components using materials with same or similar features with respect to the parent metal. A fibre-delivered disc laser and a three-way feeding nozzle are used. The responses are discussed in terms of geometry, microstructure and microhardness both in the fusion zone and in the heat-affected zone; the optimization is conducted via desirability functions, based on proper technical constraints upon numerical modelling. Reparation of real parts, where cracks are machined to produce V-grooves to be filled, is aimed.

Additive manufacturing by means of laser-aided directed metal deposition of titanium wire

“…In agreement with other findings on welding and DMD [22,29] and welding [30], occasional pore formation is random and irrespective of the processing conditions. One may assume this would not result in rejection of parts at quality checks.…”

“…In agreement with common practice in DMD [22], a number of geometrical responses in the cross-section (Fig. 5) have been measured as a function of the governing parameters: width, depth, height, and shape angle at both sides of the reported metal.…”

“…To perform AM by means of DMD, a deposition line is required involving a number of base components [22], irrespective of the form of the feedstock supply. To the purpose of this work ( Fig.…”

Simulation of Laser Heating of Aluminum and Model Validation via Two-Color Pyrometer and Shape Assessment

“…Moreover, since the model is aimed to simulate an application of repairing via metal addition where a defocused beam must be used [ 22 ], the laser beam was defocused to a processing diameter of 3 mm.…”

“…Laser heating in the form of bead-on-plate tests was performed. The operating window to achieve effective penetration in the cross-section was borrowed from previous works on the same alloy [ 22 ], even aiming for non-penetrative bead-on-plate welds to prevent porosity [ 31 ]; traveling speed and power were considered, and the results of six testing conditions have been found ( Table 1 ). For the purpose of an easier comparison of the responses, the length of the scanning path was conveniently set in order to result in 10 s heating, irrespective of the traveling speed.…”