Process Development to Repair Aluminum Components, Using EHLA and Laser DED Techniques

The article presents a new AM (Additive Manufacturing) process development, necessary to repair parts made from aluminum 6061 material, with T6 treatment. The laser DED and EHLA capabilities are evaluated for repairing Al large components. To optimize the process parameters, single track depositions were analyzed for both conventional DED (feed rate of 2m/s) and high-speed DED/EHLA (feed rate 20m/s), for AlSi10Mg and Al6061 powders. The cross sections of single tracks revealed the bonding characteristics and provided a suitable parameter selection for the repair. Three damage types were identified on the Al component, to define the specification of the repair process and to highlight the capabilities of DED and EHLA in repairing intricate surface scratches and dents. Our research is based on variation of the powder mass flow and beam power, studying the influence of these parameters on the weld bead geometry and bonding quality. The evaluation criteria include bonding defects, crack formation, porosity and dilution zone depth. The bidirectional path planning strategy was applied with a fly-in and fly-out path for the hatching adjustment and acceleration distance. Samples were etched for a qualitative microstructure analysis and the HV hardness was tested. The novelty of the paper is the new process parameters for DED and EHLA deposition strategies, to repair large Al components (6061 T6), using AlSi10Mg and Al6061 powder. Our experimental research tested the defect-free deposition and the compatibility of AlSi10Mg on the Al6061 substrate. The readers could replicate the method presented in this article, to repair by DED/EHLA large Al parts and avoid the replacement of Al components by new ones.