The United States Department of Defense heavily relies on forged components owing to their high yield strength, precision, and wear resistance. Forging dies are critical for shaping ingots or preforms into their final geometries under extreme thermo-mechanical cyclic loads. The severe operating environment leads to thermal fatigue, surface cracking, mechanical wear, and eventual failure of the forging die. This study proposes the direct energy deposition-based additive manufacturing processes as an innovative and effective solution for repairing forging dies. Eureka-450 and IN718 were deposited as repair alloys using wire arc additive manufacturing (WAAM) and wire laser additive manufacturing (WLAM) on an H-13 tool steel plate. Additionally, Eureka 635 was deposited on AISI 4142 steel by flood welding for a baseline for performance comparison with DED-based forging die repair techniques. The microstructural and mechanical properties of the interface, along with the bulk samples from the repair side, were examined using scanning electron microscopy, Vickers indentation, uniaxial tensile testing, and Charpy V-notch impact testing. The results indicated that WAAM and WLAM provided superior metallurgical bonding and significantly reduced heat affected zone (HAZ) compared to conventional methods. The DED-based repaired samples exhibit dense, defect-free microstructures at interface. The ultimate tensile strength and ductility of the interface samples were consistently lower than the bulk samples in all the cases, likely due to the formation of hard and brittle heat-affected zones near the interface, which weakened the overall strength of the interface samples. Among Eureka 450 and IN718, the former exhibited higher tensile strength but low ductility and impact strength, while the latter depicted higher impact strength and ductility. This is attributed to the martensitic crystal structure of the Eureka 450, while the austenitic crystal structure of the IN718.
Presentation Stage: Evaluation — Exploring Possibilities and Applications
